Electronic keyboard

An electronic keyboard or digital keyboard is an electronic musical instrument , an electronic or digital derivative of keyboard instruments .  Broadly speaking , in a popular music context , the term electronic keyboard or just a keyboard mostly refers to any type of digital or electronic keyboard instrument . These include synthesizers , digital pianos , stage pianos , electronic organs and digital audio workstations . However , in true musical terminology , an electronic keyboard is an inexpensive synthesizer equipped with built-in power amplifier and small loudspeakers .   Electronic keyboards are capable of recreating a wide range of instrument sounds ( piano , electric piano , Hammond organ , pipe organ , violin , etc. ) with less complex sound synthesis . Electronic keyboards are usually dedicated for home users , beginners and other non-professional users . They typically have unweighted keys . The least expensive models do not have velocity-sensitive keys ; but mid - to high-priced models do have these feature . Home keyboards typically have little if any sound editing capacity . The user typically selects from a range of preset `` voices '' or sounds , which include imitations of many instruments and some electronic synthesizer sounds . Home keyboards have a much lower cost than professional synthesizers . Casio and Yamaha are among the leading manufacturers of home keyboards .


Emergency management

-RCB- -RCB-  Disaster management ( or emergency management ) can be defined as the organization and management of resources and responsibilities for dealing with all humanitarian aspects of emergencies in particular preparedness , response and recovery in order to reduce the impact of disasters .


Emissions trading

Emissions trading or cap and trade is a government-mandated , market-based approach to controlling pollution by providing economic incentives for achieving reductions in the emissions of pollutants . In contrast to command-and-control environmental regulations such as best available technology ( BAT ) standards and government subsidies , cap and trade ( CAT ) schemes are a type of flexible environmental regulation that allows organizations to decide how best to meet policy targets . Various countries , states and groups of companies have adopted such trading systems , notably for mitigating climate change .   A central authority ( usually a governmental body ) allocates or sells a limited number of permits to discharge specific quantities of a specific pollutant per time period . Polluters are required to hold permits in amount equal to their emissions . Polluters that want to increase their emissions must buy permits from others willing to sell them . Financial derivatives of permits can also be traded on secondary markets .   In theory , polluters who can reduce emissions most cheaply will do so , achieving the emission reduction at the lowest cost to society . Cap and trade is meant to provide the private sector with the flexibility required to reduce emissions while stimulating technological innovation and economic growth .   There are active trading programs in several air pollutants . For greenhouse gases , which cause climate change , permit units are often called carbon credits . The largest greenhouse gases trading program is the European Union Emission Trading Scheme , which trades primarily in European Union Allowances ( EUAs ) ; the Californian scheme trades in California Carbon Allowances , the New Zealand scheme in New Zealand Units and the Australian scheme in Australian Units . The United States has a national market to reduce acid rain and several regional markets in nitrogen oxides .


Energy in South Australia

South Australia is rich in energy resources . It contains significant reserves of fossil fuels such as natural gas , coal , and oil -- although there are incentives to phase these out in favour of clean energy . The state also contains large amounts of uranium , including the world 's single biggest deposit at Olympic Dam , which represents 30 % of the world 's total resource .   More recently , the State has seen a rapid increase in investment in renewable energy , and is now the leading producer of wind power in Australia . South Australia has been noted for the availability of hot rocks suitable for geothermal electricity generation . The South Australian Government has released plans to make South Australia a green energy hub for Australia 's eastern seaboard .


Energy industry

The energy industry is the totality of all of the industries involved in the production and sale of energy , including fuel extraction , manufacturing , refining and distribution . Modern society consumes large amounts of fuel , and the energy industry is a crucial part of the infrastructure and maintenance of society in almost all countries .   In particular , the energy industry comprises :  the petroleum industry , including oil companies , petroleum refiners , fuel transport and end-user sales at gas stations  the gas industry , including natural gas extraction , and coal gas manufacture , as well as distribution and sales  the electrical power industry , including electricity generation , electric power distribution and sales  the coal industry  the nuclear power industry  the renewable energy industry , comprising alternative energy and sustainable energy companies , including those involved in hydroelectric power , wind power , and solar power generation , and the manufacture , distribution and sale of alternative fuels  traditional energy industry based on the collection and distribution of firewood , the use of which , for cooking and heating , is particularly common in poorer countries


Energy policy of China

The energy policy of China is a policy decided on by the Central Government with regard to energy and energy resources . Ensuring adequate energy supply to sustain economic growth has been a core concern of the Chinese government since 1949 . The country is currently the world 's largest emitter of greenhouse gases according to a Dutch research agency . However , China 's per capita emissions are still far behind the developed countries . In addition , China is the world 's leading renewable energy producer .   From 2010 to 2015 China reduced energy consumption per unit of GDP by 18 % , and CO2 emissions per unit of GDP by 20 % .   Primary energy use in China was 26,250 TWh and 20 TWh per million persons in 2009 . According to IEA the primary energy use grew 40 % and electricity use 70 % from 2004 to 2009 . The energy import was three times bigger in 2009 compared to 2004 . The share of energy import of the primary energy use was 12 % in 2009 . The CO2 emissions growth in five years ( 2004-2009 ) was 44 % .


Energy policy of India

The energy policy of India is largely defined by the country 's expanding energy deficit and increased focus on developing alternative sources of energy , particularly nuclear , solar and wind energy . India ranks 81 position in overall energy self sufficiency at 66 % in 2014 .   The primary energy consumption in India is the third biggest after China and USA with 5.3 % global share in 2015 . The total primary energy consumption from crude oil ( 195.5 Mtoe ; 27.91 % ) , natural gas ( 45.5 Mtoe ; 6.50 % ) , coal ( 407.2 Mtoe ; 58.13 % ) , nuclear energy ( 8.6 Mtoe ; 1.23 % ) , hydro electricity ( 28.1 Mtoe ; 4.01 % ) and renewable power ( 15.5 Mtoe ; 2.21 % ) is 700.5 Mtoe ( excluding traditional biomass use ) in 2015 . In 2013 , India 's net imports are nearly 144.3 million tons of crude oil , 16 Mtoe of LNG and 95 Mtoe coal totalling to 255.3 Mtoe of primary energy which is equal to 42.9 % of total primary energy consumption . About 70 % of India 's electricity generation capacity is from fossil fuels . India is largely dependent on fossil fuel imports to meet its energy demands -- by 2030 , India 's dependence on energy imports is expected to exceed 53 % of the country 's total energy consumption . In 2009-10 , the country imported 159.26 million tonnes of crude oil which amounts to 80 % of its domestic crude oil consumption and 31 % of the country 's total imports are oil imports . By the end of calendar year 2015 , India has become a power surplus country with huge power generation capacity idling for want of electricity demand . India ranks second after China in renewables production with 208.7 Mtoe in 2014 .   In 2015-16 , the per-capita energy consumption is 22.042 Giga Joules ( 0.527 Mtoe ) excluding traditional biomass use and the energy intensity of the Indian economy is 0.271 Mega Joules per INR ( 65 kcal/INR ) . Due to rapid economic expansion , India has one of the world 's fastest growing energy markets and is expected to be the second-largest contributor to the increase in global energy demand by 2035 , accounting for 18 % of the rise in global energy consumption . Given India 's growing energy demands and limited domestic fossil fuel reserves , the country has ambitious plans to expand its renewable and most worked out nuclear power programme . India has the world 's fifth largest wind power market and also plans to add about 100,000 MW of solar power capacity by 2020 . India also envisages to increase the contribution of nuclear power to overall electricity generation capacity from 4.2 % to 9 % within 25 years . The country has five nuclear reactors under construction ( third highest in the world ) and plans to construct 18 additional nuclear reactors ( second highest in the world ) by 2025 .


Energy policy of the European Union

Although the European Union has legislated in the area of energy policy for many years , the concept of introducing a mandatory and comprehensive European Union energy policy was only approved at the meeting of the informal European Council on 27 October 2005 at Hampton Court . The EU Treaty of Lisbon of 2007 legally includes solidarity in matters of energy supply and changes to the energy policy within the EU . Prior to the Treaty of Lisbon , EU energy legislation has been based on the EU authority in the area of the common market and environment . However , in practice many policy competencies in relation to energy remain at national member state level , and progress in policy at European level requires voluntary cooperation by members states .   In 2007 , the EU was importing 82 % of its oil and 57 % of its gas , which then made it the world 's leading importer of these fuels . Only 3 % of the uranium used in European nuclear reactors was mined in Europe . Russia , Canada , Australia , Niger and Kazakhstan were the five largest suppliers of nuclear materials to the EU , supplying more than 75 % of the total needs in 2009 . In 2015 , the EU imports 53 % of the energy it consumes .  In January 2014 , the EU agreed to a 40 % emissions reduction by 2030 , compared to 1990 levels , and a 27 % renewable energy target . The target is the most ambitious of any region in the world , and is expected to provide 70,000 full-time jobs and cut $ 33bn in fossil fuel imports .   In 2015 , the Framework Strategy for Energy Union is launched as one of the European Commission 's 10 Priorities .


Energy policy of the United States

The energy policy of the United States is determined by federal , state , and local entities in the United States , which address issues of energy production , distribution , and consumption , such as building codes and gas mileage standards . Energy policy may include legislation , international treaties , subsidies and incentives to investment , guidelines for energy conservation , taxation and other public policy techniques .   Several mandates have been proposed over the years , such as gasoline will never exceed $ 1.00 / gallon ( Nixon ) , and the United States will never again import as much oil as it did in 1977 ( Carter ) , but no comprehensive long-term energy policy has been proposed , although there has been concern over this failure . Three Energy Policy Acts have been passed , in 1992 , 2005 , and 2007 , which include many provisions for conservation , such as the Energy Star program , and energy development , with grants and tax incentives for both renewable energy and non-renewable energy .   There is also criticism that federal energy policies since the 1973 oil crisis have been dominated by crisis-mentality thinking , promoting expensive quick fixes and single-shot solutions that ignore market and technology realities . Instead of providing stable rules that support basic research while leaving plenty of scope for American entrepreneurship and innovation , congresses and presidents have repeatedly backed policies which promise solutions that are politically expedient , but whose prospects are doubtful , without adequate consideration of the dollar costs , environmental costs , or national security costs of their actions .   State-specific energy-efficiency incentive programs also play a significant role in the overall energy policy of the United States .  The United States refused to endorse the Kyoto Protocol , preferring to let the market drive CO2 reductions to mitigate global warming , which will require CO2 emission taxation . The administration of Barack Obama has proposed an aggressive energy policy reform , including the need for a reduction of CO2 emissions , with a cap and trade program , which could help encourage more clean renewable , sustainable energy development . Thanks to new technologies such as fracking , the United States has in 2014 resumed its former role as the top oil producer in the world .


Energy subsidy

Energy subsidies are measures that keep prices for consumers below market levels or for producers above market levels, or reduce costs for consumers and producers. Energy subsidies may be direct cash transfers to producers, consumers, or related bodies, as well as indirect support mechanisms, such as tax exemptions and rebates, price controls, trade restrictions, and limits on market access.  Eliminating fossil fuel subsidies would greatly reduce global carbon emissions and would reduce the health risks of air pollution.


Engine

An engine or motor is a machine designed to convert one form of energy into mechanical energy . Heat engines burn a fuel to create heat , which is then used to create a force . Electric motors convert electrical energy into mechanical motion ; pneumatic motors use compressed air and clockwork motors in wind-up toys use elastic energy . In biological systems , molecular motors , like myosins in muscles , use chemical energy to create forces and eventually motion .


Ensemble forecasting

Ensemble forecasting is a method used in numerical weather prediction . Instead of making a single forecast of the most likely weather , a set ( or ensemble ) of forecasts are produced . This set of forecasts aims to give an indication of the range of possible future states of the atmosphere . Ensemble forecasting is a form of Monte Carlo analysis . The multiple simulations are conducted to account for the two usual sources of uncertainty in forecast models : ( 1 ) the errors introduced by the use of imperfect initial conditions , amplified by the chaotic nature of the evolution equations of the atmosphere , this is often referred to as sensitive dependence on the initial conditions ; and ( 2 ) errors introduced because of imperfections in the model formulation , such as the approximate mathematical methods to solve the equations . Ideally , the verified future atmospheric state should fall within the predicted ensemble spread , and the amount of spread should be related to the uncertainty ( error ) of the forecast . In general , this approach can be used to make probabilistic forecasts of any dynamical system , and not just for weather prediction .   Today ensemble predictions are commonly made at most of the major operational weather prediction facilities worldwide , including :  National Centers for Environmental Prediction ( NCEP of the US )  European Centre for Medium-Range Weather Forecasts ( ECMWF )  United Kingdom Met Office  Météo-France  Environment Canada  Japan Meteorological Agency  Bureau of Meteorology ( Australia )  China Meteorological Administration ( CMA )  Korea Meteorological Administration  CPTEC ( Brazil )  Experimental ensemble forecasts are made at a number of universities , such as the University of Washington , and ensemble forecasts in the US are also generated by the US Navy and Air Force . There are various ways of viewing the data such as spaghetti plots , ensemble means or Postage Stamps where a number of different results from the models run can be compared .


Environmental degradation

Environmental degradation is the deterioration of the environment through depletion of resources such as air , water and soil ; the destruction of ecosystems ; habitat destruction ; the extinction of wildlife ; and pollution . It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable . As indicated by the I = PAT equation , environmental impact ( I ) or degradation is caused by the combination of an already very large and increasing human population ( P ) , continually increasing economic growth or per capita affluence ( A ) , and the application of resource depleting and polluting technology ( T ) .   Environmental degradation is one of the ten threats officially cautioned by the High-level Panel on Threats , Challenges and Change of the United Nations . The United Nations International Strategy for Disaster Reduction defines environmental degradation as `` The reduction of the  capacity of the environment to meet social and ecological objectives , and needs '' . Environmental degradation is of many types . When natural habitats are destroyed or natural resources are depleted , the environment is degraded . Efforts to counteract this problem include environmental protection and environmental resources management .


Environmental economics

Environmental economics is a sub-field of economics that is concerned with environmental issues . Quoting from the National Bureau of Economic Research Environmental Economics program :   -LSB- ... -RSB- Environmental Economics -LSB- ... -RSB- undertakes theoretical or empirical studies of the economic effects of national or local environmental policies around the world -LSB- ... -RSB- . Particular issues include the costs and benefits of alternative environmental policies to deal with air pollution , water quality , toxic substances , solid waste , and global warming .   Environmental economics is distinguished from ecological economics in that ecological economics emphasizes the economy as a subsystem of the ecosystem with its focus upon preserving natural capital . One survey of German economists found that ecological and environmental economics are different schools of economic thought , with ecological economists emphasizing `` strong '' sustainability and rejecting the proposition that natural capital can be substituted by human-made capital .


Environmental impact of aviation

The environmental impact of aviation occurs because aircraft engines emit heat , noise , particulates and gases which contribute to climate change and global dimming . Among others airplanes emit particles and gases such as carbon dioxide , water vapor , hydrocarbons , carbon monoxide , nitrogen oxides , sulfur oxides , lead and black carbon which interact among themselves and with the atmosphere .   Despite emission reductions from automobiles and more fuel-efficient and less polluting turbofan and turboprop engines , the rapid growth of air travel in recent years contributes to an increase in total pollution attributable to aviation . From 1992 to 2005 , passenger kilometers increased 5.2 % per year . And in the European Union , greenhouse gas emissions from aviation increased by 87 % between 1990 and 2006 .   Comprehensive research shows that despite anticipated efficiency innovations to airframes , engines , aerodynamics and flight operations , there is no end in sight -- even many decades out -- to rapid growth in CO2 emissions from air travel and air freight , due to projected continual growth in air travel . This is because international aviation emissions have escaped international regulation up to the ICAO triennial conference in October 2016 agreed on the CORSIA offset scheme , and because of the lack of taxes on aviation fuel worldwide , lower fares become more frequent than otherwise which gives a competitive advantage over other transportation modes . Unless market constraints are put in place this growth in aviation 's emissions will result in the sector 's emissions amounting to all or nearly all of the annual global emissions budget by mid-century , if climate change is to be held to a temperature increase of 2 ° C or less .   There is an ongoing debate about possible taxation of air travel and the inclusion of aviation in an emissions trading scheme , with a view to ensuring that the total external costs of aviation are taken into account .


Environmental impact of aviation in the United Kingdom

The environmental impact of aviation in the United Kingdom is increasing due to the increasing demand for air travel in the country . In the past 25 years the UK air transport industry has seen sustained growth , and the demand for passenger air travel in particular is forecast to increase more than twofold , to 465 million passengers , by 2030 . Two airports ; London Heathrow Airport and London Gatwick Airport , are amongst the top ten busiest airports in the world for international passenger traffic . Whilst more than half of all passengers travelling by air in the UK currently travel via the five London area airports , regional airports have experienced the most growth in recent years , due to the success of ` no-frills ' airlines over the last decade .   The ability of the existing airport infrastructure to meet forecast demand is limited , and government policy published in 2003 supports the development of additional airport capacity by 2030 to address this . The strategy is generally based on making the best use of existing facilities , although an additional five new runways nationwide are considered to be necessary , three of them at the London airports of Stansted , Heathrow and , towards the end of the timeframe involved , Gatwick . This policy is designed to be a balanced and measured approach to the future of the air transport industry ; one that recognises both an economic advantage in providing for growth in demand for air travel and also the need to address the consequent environmental impacts . The strategy has been criticised by the House of Commons Environmental Audit Select Committee , by environmentalist and campaign groups , and in research papers , for implementing a predict and provide model that overstates the economic advantages whilst paying insufficient heed to the environmental consequences .   Support for airport expansion is based on an economic case that regards the air transport industry not only as an important industry in its own right , but also as a facilitator of growth for the economy as a whole . One study predicts that the government 's strategy will realise an additional # 13 billion per annum in Gross Domestic Product ( GDP ) by 2030 . Another study which is critical of the government approach , and which favours addressing environmental impacts through increased taxation of air transport , indicates a negative economic benefit resulting from airport expansion . In 2006 the industry was responsible for over 6 per cent of all UK carbon emissions , a figure that is set to rise as demand increases . Under current strategies of emissions reduction and growth in air transport , air travel in the UK could account for up to 50 per cent of the UK carbon budget by 2050 . Industry attempts to address this issue are longer term efforts based on technological and operational improvements , whilst government policy is based on the inclusion of air transport within emissions trading schemes . Critics advocate a shift in government policy to address environmental impacts by constraining the growth in demand for air travel , primarily through the use of economic instruments to price air travel less attractively . Local environmental issues include noise and air quality , and the impact of these , particularly in the case of the former , is subject to debate . Government policy generally is that these are local issues best addressed locally , and has introduced legislation designed to facilitate this .


Environmental impact of the coal industry

The environmental impact of the coal industry includes issues such as land use , waste management , water and air pollution , caused by the coal mining , processing and the use of its products . In addition to atmospheric pollution , coal burning produces hundreds of millions of tons of solid waste products annually , including fly ash , bottom ash , and flue-gas desulfurization sludge , that contain mercury , uranium , thorium , arsenic , and other heavy metals .   There are severe health effects caused by burning coal . According to a report by the World Health Organization in 2008 , coal particulates pollution are estimated to shorten approximately 1,000,000 lives annually worldwide . A 2004 study commissioned by environmental groups , but contested by the US EPA , concluded that coal burning costs 24,000 lives a year in the United States .   Historically , coal mining has been a very dangerous activity and the list of historical coal mining disasters is a long one . Underground mining hazards include suffocation , gas poisoning , roof collapse and gas explosions . Open cut hazards are principally mine wall failures and vehicle collisions . In the United States , an average of 26 coal miners per year died in the decade 2005-2014 .


Environmental impact of wind power

The environmental impact of wind power when compared to the environmental impacts of fossil fuels , is relatively minor . Compared with other low carbon power sources , wind turbines have some of the lowest global warming potential per unit of electrical energy generated . According to the IPCC , in assessments of the life-cycle global warming potential of energy sources , wind turbines have a median value of between 15 and 11 ( geq/kWh ) depending on whether off - or onshore turbines are being assessed .   While wind turbine installations may cover a large area , they are compatible with many land uses such as farming and grazing , as only small areas of turbine foundations and infrastructure are made unavailable for use .   Wind turbines generate some noise . At a residential distance of 300 m this may be around 45 dB , which is slightly louder than a refrigerator . At 1.5 km distance most wind turbines become inaudible .  From a fundamental biological point of view , it is known that loud noise increases stress and stress causes diseases .  Peer-reviewed research has generally supported the view that when properly sited wind turbines do not affect human health from noise . However , when improperly sited , data from the monitoring of two groups of growing geese revealed substantially lower body weights and higher concentrations of a stress hormone in the blood of the first group of geese who were situated 50 meters away compared to a second group which was at a distance of 500 meters from the turbine .   Aesthetic aspects of wind turbines and resulting changes of the visual landscape can be significant . Conflicts arise especially in scenic and heritage protected landscapes . Siting restrictions ( such as setbacks ) have often been implemented to limit any intrusive environmental impacts .   There are reports of bird and bat mortality at wind turbines as there are around other artificial structures . The scale of the ecological impact may or may not be significant , depending on specific circumstances . Prevention and mitigation of wildlife fatalities , and protection of peat bogs , affect the siting and operation of wind turbines .


Environmental issues in Thailand

Thailand introduced its Seventh Economic and Social Development Plan ( 1992 -- 1996 ) , declaring that protecting the environment was a top priority of the Thai government . The plan sought to achieve sustainable growth and stability , especially in the petrochemical , engineering , electronics , and basic industries .   Thailand 's dramatic economic growth has caused numerous environmental issues . The country faces problems with air and water pollution , declining wildlife populations , deforestation , soil erosion , water scarcity , and waste issues . According to a 2004 indicator , the cost of air and water pollution for the country scales up to approximately 1.6 -- 2.6 percent of GDP per year . As such , Thailand 's economic growth has come at great cost in damage to its people and environment .


Environmental issues in the Philippines

The Environment of Philippines is prone to natural disasters , particularly typhoons , floods , landslides , volcanic eruptions , earthquakes , and tsunamis , lying as it does astride the typhoon belt , in the active volcanic region known as the Pacific Ring of Fire , and in the geologically unstable region between the Pacific and Eurasian tectonic plates .   The Philippines also suffers major human-caused environmental degradation aggravated by a high annual population growth rate , including loss of agricultural lands , deforestation , soil erosion , air and water pollution , improper disposal of solid and toxic wastes , loss of coral reefs , mismanagement and abuse of coastal resources , and overfishing .


Environmental policy of the Donald Trump administration

The environmental policy of the Donald Trump administration represents a shift from the policy priorities and goals of his predecessor , Barack Obama . During the campaign Trump often described environmental regulations as an impediment to business . He promised to roll back many regulations and end a moratorium on the leasing of federal coal reserves .   Immediately upon his inauguration , the White House released an `` America First Energy Plan '' , which focused on fossil fuels and did not mention renewable energy . The plan would repeal many Obama policies including the Climate Action Plan and the Waters of the U.S. rule , and limit the Environmental Protection Agency 's mission to protecting air and water quality . Within days of taking office he signed executive orders to approve two controversial pipelines and to require federal review of the Clean Water Rule and the Clean Power Plan . He also invited American manufacturers to suggest what regulations should be eliminated ; industry leaders submitted 168 comments , of which nearly half targeted Environmental Protection Agency rules . In March 2017 he released a proposed 2018 budget which would cut funding for the EPA by 31 % . In May 2017 Congress approved a budget for the balance of the 2017-18 year which cuts the EPA 's funding by 1 % and eliminates no jobs .   Trump 's appointments to key agencies dealing in energy and environmental policy reflected his commitment to deregulation , particularly of the fossil fuel industry . Several of his cabinet picks , such as Rick Perry as Secretary of Energy and Scott Pruitt as Administrator of the Environmental Protection Agency , were of people with a history of opposition to the agency they were named to head .


Environmental sociology

Environmental sociology is typically defined as the sociological study of societal-environmental interactions , although this definition immediately presents the problem of integrating human cultures with the rest of the environment . Although the focus of the field is the relationship between society and environment in general , environmental sociologists typically place special emphasis on studying the social factors that cause environmental problems , the societal impacts of those problems , and efforts to solve the problems . In addition , considerable attention is paid to the social processes by which certain environmental conditions become socially defined as problems .   Although there was sometimes acrimonious debate between the constructivist and realist `` camps '' within environmental sociology in the 1990s , the two sides have found considerable common ground as both increasingly accept that while most environmental problems have a material reality they nonetheless become known only via human processes such as scientific knowledge , activists ' efforts , and media attention . In other words , most environmental problems have a real ontological status despite our knowledge/awareness of them stemming from social processes , processes by which various conditions are constructed as problems by scientists , activists , media and other social actors . Correspondingly , environmental problems must all be understood via social processes , despite any material basis they may have external to humans . This interactiveness is now broadly accepted , but many aspects of the debate continue in contemporary research in the field .


Environmental threats to the Great Barrier Reef

The Great Barrier Reef , the world 's largest reef system , stretching along the East coast of Australia from the northern tip down to the town of Bundaberg , is composed of roughly 2,900 individual reefs and 940 islands and cays that stretch for 2,300 kilometres ( 1,616 mi ) and cover an area of approximately 344,400 km2 . The reef is located in the Coral Sea , off the coast of Queensland in northeast Australia . A large part of the reef is protected by the Great Barrier Reef Marine Park .   According to the 2014 report of the Australian Government 's Great Barrier Reef Marine Park Authority ( GBRMPA ) , says that climate change is the most significant environmental threat to the Great Barrier Reef , while the other major environmental pressures are listed as decreased water quality from land-based runoff , impacts from coastal development and some persistent impacts from fishing activities . The reef is also threatened by storms , coral bleaching and ocean acidification . The 2014 report also shows that , while numerous marine life species have recovered after previous declines , the strength of the dugong population is continuing to decline . Terry Hughes , Federation Fellow , ARC Centre of Excellence for Coral Reef Studies at James Cook University , wrote in a 14 August 2014 Conversation piece that harmful government policies and ongoing conflicts of interest over mining royalties are risks of an equivalent magnitude .   The GBRMPA consider climate change , poor water quality , coastal development , and some impacts from fishing to be the area 's major threats , but reef scientists Jon Day , Bob Pressey , Jon Brodie and Hughes stated that the `` cumulative effects of many combined impacts '' is the real issue .   In a Conversation Article , Mathieu Mongin , a biogeochemical modeller at CSIRO and colleagues mapped parts of the Great Barrier Reef that are most exposed to ocean acidification . This map of pH on the Great Barrier Reef presents the exposure to ocean acidification on each of the 3,581 reefs , providing managers with the information they need to tailor management to individual reefs . The Great Barrier Reef is not a singular reef nor a physical barrier that prevents exchange between reefs ; it is a mixture of thousands of productive reefs and shallow areas lying on a continental shelf with complex oceanic circulation .


Eocene

The Eocene ( -LSB- pronˈiːəˌsiːn , _ ˈiːoʊ - -RSB- ) Epoch , lasting from , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era . The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch . The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C . The end is set at a major extinction event called the Grande Coupure ( the `` Great Break '' in continuity ) or the Eocene -- Oligocene extinction event , which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay . As with other geologic periods , the strata that define the start and end of the epoch are well identified , though their exact dates are slightly uncertain .   The name Eocene comes from the Ancient Greek ἠώς ( ēṓs , `` dawn '' ) and καινός ( kainós , `` new '' ) and refers to the `` dawn '' of modern ( ` new ' ) fauna that appeared during the epoch .


Equator

An equator is the intersection of the surface of a rotating spheroid ( such as a planet ) with the plane perpendicular to the axis of rotation and midway between its poles .  On Earth , the Equator is an imaginary line on the surface , equidistant from the North and South Poles , dividing the Earth into Northern and Southern Hemispheres . It is about 40,075 km long , of which 78.7 % lies across water and 21.3 % over land .


Ethiopia

Ethiopia ( -LSB- ˌiːθiˈoʊpiə -RSB- ኢትዮጵያ , , ) , officially the Federal Democratic Republic of Ethiopia ( የኢትዮጵያ ፌዴራላዊ ዲሞክራሲያዊ ሪፐብሊክ , yeʾĪtiyoṗṗya Fēdēralawī Dēmokirasīyawī Rīpebilīk ) , is a country located in the Horn of Africa . It shares borders with Eritrea to the north and northeast , Djibouti and Somalia to the east , Sudan and South Sudan to the west , and Kenya to the south . With over 100 million inhabitants , Ethiopia is the most populous landlocked country in the world , as well as the second-most populous nation on the African continent after Nigeria . It occupies a total area of 1,100,000 km2 , and its capital and largest city is Addis Ababa .   Some of the oldest evidence for anatomically modern humans has been found in Ethiopia . It is widely considered as the region from which modern humans first set out for the Middle East and places beyond . According to linguists , the first Afroasiatic-speaking populations settled in the Horn region during the ensuing Neolithic era . Tracing its roots to the 2nd millennium BC , Ethiopia was a monarchy for most of its history . During the first centuries AD , the Kingdom of Aksum maintained a unified civilization in the region , followed by the Ethiopian Empire circa 1137 . Ethiopia derived prestige with its uniquely successful military resistance during the late 19th-century Scramble for Africa , becoming the only African country to defeat a European colonial power and retain its sovereignty . Subsequently , many African nations adopted the colors of Ethiopia 's flag following their independence . It was the first independent African member of the 20th-century League of Nations and the United Nations . In 1974 , at the end of Haile Selassie 's reign , power fell to a communist military dictatorship known as the Derg , backed by the Soviet Union , until it was defeated by the Ethiopian People 's Revolutionary Democratic Front , which has ruled since about the time of the collapse of the Soviet Union in 1991 .   Ethiopia 's ancient Ge'ez script , also known as Ethiopic , is one of the oldest alphabets still in use in the world . The Ethiopian calendar , which is approximately seven years and three months behind the Gregorian calendar , co-exists alongside the Borana calendar . A majority of the population adheres to Christianity ( mainly the Ethiopian Orthodox Tewahedo Church and P'ent ` ay ) , while around a third follows Islam ( primarily Sunni Islam ) . The country is the site of the Migration to Abyssinia and the oldest Muslim settlement in Africa at Negash . A substantial population of Ethiopian Jews , known as Bete Israel , resided in Ethiopia until the 1980s , but most of them have since emigrated to Israel . Ethiopia is a multilingual nation with around 80 ethnolinguistic groups , the four largest of which are the Oromiffa , Amhara , Somali , and Tigrayans . Most people in the country speak Afroasiatic languages of the Cushitic or Semitic branches . Additionally , Omotic languages are spoken by ethnic minority groups inhabiting the southern regions . Nilo-Saharan languages are also spoken by the nation 's Nilotic ethnic minorities .   Ethiopia is the place of origin for the coffee bean which originated from the place called Kefa ( which was one of the 14 provinces in the old Ethiopian administration ) . It is a land of natural contrasts , with its vast fertile West , jungles , and numerous rivers , and the world 's hottest settlement of Dallol in its north . The Ethiopian Highlands are Africa 's largest continuous mountain ranges , and Sof Omar Caves contain Africa 's largest cave . Ethiopia has the most UNESCO World Heritage Sites in Africa .   Ethiopia is one of the founding members of the UN , the Group of 24 ( G-24 ) , the Non-Aligned Movement , G-77 and the Organisation of African Unity . Ethiopia 's capital city Addis Ababa serves as the headquarters of the African Union , the Pan African Chamber of Commerce and Industry , the United Nations Economic Commission for Africa , African Aviation Training HQ , the African Standby Force , and many of the global NGOs focused on Africa . In the 1970s and 1980s , Ethiopia suffered from civil wars and communist purges which devastated its economy . The country has begun to recover recently however , and now has the largest economy ( by GDP ) in East Africa and Central Africa . According to Global Fire Power , Ethiopia has the 42nd most powerful military in the world , and the third most powerful in Africa .


Europa (moon)

Europa -LSB- jʊˈroʊpə -RSB- ( Jupiter II ) , is the smallest of the four Galilean moons orbiting Jupiter , and the sixth-closest to the planet . It is also the sixth-largest moon in the Solar System . Europa was discovered in 1610 by Galileo Galilei and was named after Europa , the legendary mother of King Minos of Crete and lover of Zeus ( the Greek equivalent of the Roman god Jupiter ) .   Slightly smaller than Earth 's Moon , Europa is primarily made of silicate rock and has a water-ice crust and probably an iron -- nickel core . It has a tenuous atmosphere composed primarily of oxygen . Its surface is striated by cracks and streaks , whereas craters are relatively rare . In addition to Earth-bound telescope observations , Europa has been examined by a succession of space probe flybys , the first occurring in the early 1970s .   Europa has the smoothest surface of any known solid object in the Solar System . The apparent youth and smoothness of the surface have led to the hypothesis that a water ocean exists beneath it , which could conceivably harbor extraterrestrial life . The predominant model suggests that heat from tidal flexing causes the ocean to remain liquid and drives ice movement similar to plate tectonics , absorbing chemicals from the surface into the ocean below . Sea salt from a subsurface ocean may be coating some geological features on Europa , suggesting that the ocean is interacting with the seafloor . This may be important in determining if Europa could be habitable . In addition , the Hubble Space Telescope detected water vapor plumes similar to those observed on Saturn 's moon Enceladus , which are thought to be caused by erupting cryogeysers .   The Galileo mission , launched in 1989 , provides the bulk of current data on Europa . No spacecraft has yet landed on Europa , although there have been several proposed exploration missions . The European Space Agency 's Jupiter Icy Moon Explorer ( JUICE ) is a mission to Ganymede that is due to launch in 2022 , and will include two flybys of Europa . NASA 's planned Europa Clipper will be launched in the mid-2020s .


Europe

Europe is a continent that comprises the westernmost part of Eurasia . Europe is bordered by the Arctic Ocean to the north , the Atlantic Ocean to the west , and the Mediterranean Sea to the south . The eastern boundary with Asia is a historical and cultural construct , as there is no clear physical and geographical separation between them ; Europe is generally considered as separated from Asia by the watershed divides of the Ural and Caucasus Mountains , the Ural River , the Caspian and Black Seas , and the waterways of the Turkish Straits . Yet the non-oceanic borders of Europe -- a concept dating back to classical antiquity -- are arbitrary . The primarily physiographic term `` continent '' as applied to Europe also incorporates cultural and political elements whose discontinuities are not always reflected by the continent 's current overland boundaries .   Europe covers about 10,180,000 km2 , or 2 % of the Earth 's surface ( 6.8 % of land area ) . Politically , Europe is divided into about fifty sovereign states of which the Russian Federation is the largest and most populous , spanning 39 % of the continent and comprising 15 % of its population .  Europe had a total population of about 740 million ( about 11 % of world population ) .   The European climate is largely affected by warm Atlantic currents that temper winters and summers on much of the continent , even at latitudes along which the climate in Asia and North America is severe . Further from the sea , seasonal differences are more noticeable than close to the coast .   Europe , in particular ancient Greece , was the birthplace of Western civilization . The fall of the Western Roman Empire , during the migration period , marked the end of ancient history and the beginning of an era known as the Middle Ages . Renaissance humanism , exploration , art , and science led to the modern era . From the Age of Discovery onwards , Europe played a predominant role in global affairs . Between the 16th and 20th centuries , European powers controlled at various times the Americas , most of Africa , Oceania , and the majority of Asia .   The Industrial Revolution , which began in Great Britain at the end of the 18th century , gave rise to radical economic , cultural , and social change in Western Europe , and eventually the wider world . Both world wars took place for the most part in Europe , contributing to a decline in Western European dominance in world affairs by the mid-20th century as the Soviet Union and the United States took prominence . During the Cold War , Europe was divided along the Iron Curtain between NATO in the west and the Warsaw Pact in the east , until the revolutions of 1989 and fall of the Berlin Wall .   In 1955 , the Council of Europe was formed following a speech by Sir Winston Churchill , with the idea of unifying Europe to achieve common goals . It includes all states except for Belarus , Kazakhstan and Vatican City . Further European integration by some states led to the formation of the European Union , a separate political entity that lies between a confederation and a federation . The EU originated in Western Europe but has been expanding eastward since the fall of the Soviet Union in 1991 . The currency of most countries of the European Union , the euro , is the most commonly used among Europeans ; and the EU 's Schengen Area abolishes border and immigration controls among most of its member states . The European Anthem is `` Ode to Joy '' and states celebrate peace and unity on Europe Day .


The European Centre for Medium-Range Weather Forecasts , ECMWF , is an independent intergovernmental organisation supported by most of the nations of Europe and is based at Shinfield Park , Reading , United Kingdom .  It operates one of the largest supercomputer complexes in Europe and the world 's largest archive of numerical weather prediction data .  The Centre is considering an offer from the Italian Government to move ECMWF 's data centre to Bologna , Italy . The new site , a former tobacco factory , would be redesigned by the architecture firm gmp .


European Southern Observatory

The European Southern Observatory ( ESO , formally : European Organization for Astronomical Research in the Southern Hemisphere ; Organisation Européenne pour des Recherches Astronomiques dans l'Hémisphere Austral ) is a 16-nation intergovernmental research organization for ground-based astronomy . Created in 1962 , ESO has provided astronomers with state-of-the-art research facilities and access to the southern sky . The organisation employs about 730 staff members and receives annual member state contributions of approximately $ 131 million . Its observatories are located in northern Chile .   ESO has built and operated some of the largest and most technologically advanced telescopes . These include the New Technology Telescope , an early pioneer in the use of active optics , and the Very Large Telescope ( VLT ) , which consists of four individual telescopes , each with a primary mirror 8.2 metre across , and four smaller auxiliary telescopes . The Atacama Large Millimeter Array observes the universe in the millimetre and submillimetre wavelength ranges , and is the world 's largest ground-based astronomy project to date . It was completed in March 2013 in an international collaboration by Europe ( represented by ESO ) , North America , East Asia and Chile .   Currently under construction is the European Extremely Large Telescope . It will use a 39.3-metre-diameter segmented mirror , and become the world 's largest optical reflecting telescope when operational in 2024 . Its light-gathering power will allow detailed studies of planets around other stars , the first objects in the universe , supermassive black holes , and the nature and distribution of the dark matter and dark energy which dominate the universe .   ESO 's observing facilities have made astronomical discoveries and produced several astronomical catalogues . Its findings include the discovery of the most distant gamma-ray burst and evidence for a black hole at the centre of the Milky Way . In 2004 , the VLT allowed astronomers to obtain the first picture of an extrasolar planet ( 2M1207b ) orbiting a brown dwarf 173 light-years away . The High Accuracy Radial Velocity Planet Searcher ( HARPS ) instrument installed in another ESO telescope led to the discovery of extrasolar planets , including Gliese 581c -- one of the smallest planets seen outside the solar system .


Evidence

Evidence , broadly construed , is anything presented in support of an assertion . This support may be strong or weak . The strongest type of evidence is that which provides direct proof of the truth of an assertion . At the other extreme is evidence that is merely consistent with an assertion but does not rule out other , contradictory assertions , as in circumstantial evidence .   In law , rules of evidence govern the types of evidence that are admissible in a legal proceeding . Types of legal evidence include testimony , documentary evidence , and physical evidence . The parts of a legal case which are not in controversy are known , in general , as the `` facts of the case . '' Beyond any facts that are undisputed , a judge or jury is usually tasked with being a trier of fact for the other issues of a case . Evidence and rules are used to decide questions of fact that are disputed , some of which may be determined by the legal burden of proof relevant to the case . Evidence in certain cases ( e.g. capital crimes ) must be more compelling than in other situations ( e.g. minor civil disputes ) , which drastically affects the quality and quantity of evidence necessary to decide a case .   Scientific evidence consists of observations and experimental results that serve to support , refute , or modify a scientific hypothesis or theory , when collected and interpreted in accordance with the scientific method .   In philosophy , the study of evidence is closely tied to epistemology , which considers the nature of knowledge and how it can be acquired .


Evidence-based medicine

Evidence-based medicine ( EBM ) is an approach to medical practice intended to optimize decision-making by emphasizing the use of evidence from well-designed and well-conducted research . Although all medicine based on science has some degree of empirical support , EBM goes further , classifying evidence by its epistemologic strength and requiring that only the strongest types ( coming from meta-analyses , systematic reviews , and randomized controlled trials ) can yield strong recommendations ; weaker types ( such as from case-control studies ) can yield only weak recommendations . The term was originally used to describe an approach to teaching the practice of medicine and improving decisions by individual physicians about individual patients . Use of the term rapidly expanded to include a previously described approach that emphasized the use of evidence in the design of guidelines and policies that apply to groups of patients and populations ( `` evidence-based practice policies '' ) . It has subsequently spread to describe an approach to decision-making that is used at virtually every level of health care as well as other fields ( evidence-based practice ) .   Whether applied to medical education , decisions about individuals , guidelines and policies applied to populations , or administration of health services in general , evidence-based medicine advocates that to the greatest extent possible , decisions and policies should be based on evidence , not just the beliefs of practitioners , experts , or administrators . It thus tries to assure that a clinician 's opinion , which may be limited by knowledge gaps or biases , is supplemented with all available knowledge from the scientific literature so that best practice can be determined and applied . It promotes the use of formal , explicit methods to analyze evidence and makes it available to decision makers . It promotes programs to teach the methods to medical students , practitioners , and policy makers .


Evolution

Evolution is change in the heritable characteristics of biological populations over successive generations . Evolutionary processes give rise to biodiversity at every level of biological organisation , including the levels of species , individual organisms , and molecules .   All life on Earth shares a common ancestor known as the last universal common ancestor ( LUCA ) , which lived approximately 3.5 -- 3.8 billion years ago , although a study in 2015 found `` remains of biotic life '' from 4.1 billion years ago in ancient rocks in Western Australia . In July 2016 , scientists reported identifying a set of 355 genes from the LUCA of all organisms living on Earth .   Repeated formation of new species ( speciation ) , change within species ( anagenesis ) , and loss of species ( extinction ) throughout the evolutionary history of life on Earth are demonstrated by shared sets of morphological and biochemical traits , including shared DNA sequences . These shared traits are more similar among species that share a more recent common ancestor , and can be used to reconstruct a biological `` tree of life '' based on evolutionary relationships ( phylogenetics ) , using both existing species and fossils . The fossil record includes a progression from early biogenic graphite , to microbial mat fossils , to fossilized multicellular organisms . Existing patterns of biodiversity have been shaped both by speciation and by extinction . More than 99 percent of all species that ever lived on Earth are estimated to be extinct . Estimates of Earth 's current species range from 10 to 14 million , of which about 1.9 million are estimated to have been named and 1.6 million documented in a central database to date . More recently , in May 2016 , scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described .   In the mid-19th century , Charles Darwin formulated the scientific theory of evolution by natural selection , published in his book On the Origin of Species ( 1859 ) . Evolution by natural selection is a process demonstrated by the observation that more offspring are produced than can possibly survive , along with three facts about populations : 1 ) traits vary among individuals with respect to morphology , physiology , and behaviour ( phenotypic variation ) , 2 ) different traits confer different rates of survival and reproduction ( differential fitness ) , and 3 ) traits can be passed from generation to generation ( heritability of fitness ) . Thus , in successive generations members of a population are replaced by progeny of parents better adapted to survive and reproduce in the biophysical environment in which natural selection takes place . This teleonomy is the quality whereby the process of natural selection creates and preserves traits that are seemingly fitted for the functional roles they perform . The processes by which the changes occur , from one generation to another , are called evolutionary processes or mechanisms . The four most widely recognized evolutionary processes are natural selection ( including sexual selection ) , genetic drift , mutation and gene migration due to genetic admixture . Natural selection and genetic drift sort variation ; mutation and gene migration create variation .   Consequences of selection can include meiotic drive ( unequal transmission of certain alleles ) , nonrandom mating and genetic hitchhiking .  In the early 20th century the modern evolutionary synthesis integrated classical genetics with Darwin 's theory of evolution by natural selection through the discipline of population genetics . The importance of natural selection as a cause of evolution was accepted into other branches of biology . Moreover , previously held notions about evolution , such as orthogenesis , evolutionism , and other beliefs about innate `` progress '' within the largest-scale trends in evolution , became obsolete . Scientists continue to study various aspects of evolutionary biology by forming and testing hypotheses , constructing mathematical models of theoretical biology and biological theories , using observational data , and performing experiments in both the field and the laboratory .   In terms of practical application , an understanding of evolution has been instrumental to developments in numerous scientific and industrial fields , including agriculture , human and veterinary medicine , and the life sciences in general . Discoveries in evolutionary biology have made a significant impact not just in the traditional branches of biology but also in other academic disciplines , including biological anthropology , and evolutionary psychology . Evolutionary computation , a sub-field of artificial intelligence , involves the application of Darwinian principles to problems in computer science .


Evolution as fact and theory

Many scientists and philosophers of science have described evolution as fact and theory , a phrase which was used as the title of an article by paleontologist Stephen Jay Gould in 1981 . He describes fact in science as meaning data , not absolute certainty but `` confirmed to such a degree that it would be perverse to withhold provisional assent '' . A scientific theory is a well-substantiated explanation of such facts . The facts of evolution come from observational evidence of current processes , from imperfections in organisms recording historical common descent , and from transitions in the fossil record . Theories of evolution provide a provisional explanation for these facts .   Each of the words `` evolution '' , `` fact '' and `` theory '' has several meanings in different contexts . Evolution means change over time , as in stellar evolution . In biology it refers to observed changes in organisms , to their descent from a common ancestor , and at a technical level to a change in gene frequency over time ; it can also refer to explanatory theories ( such as Charles Darwin 's theory of natural selection ) which explain the mechanisms of evolution . To a scientist , fact can describe a repeatable observation that all can agree on ; it can refer to something that is so well established that nobody in a community disagrees with it ; and it can also refer to the truth or falsity of a proposition . To the public , theory can mean an opinion or conjecture ( e.g. , `` it 's only a theory '' ) , but among scientists it has a much stronger connotation of `` well-substantiated explanation '' . With this number of choices , people can often talk past each other , and meanings become the subject of linguistic analysis .   Evidence for evolution continues to be accumulated and tested . The scientific literature includes statements by evolutionary biologists and philosophers of science demonstrating some of the different perspectives on evolution as fact and theory .


Exhaust gas

Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas , gasoline , petrol , biodiesel blends , diesel fuel , fuel oil , or coal . According to the type of engine , it is discharged into the atmosphere through an exhaust pipe , flue gas stack , or propelling nozzle . It often disperses downwind in a pattern called an exhaust plume .   It is a major component of motor vehicle emissions ( and from stationary internal combustion engines ) , which can also include :  Crankcase blow-by  Evaporation of unused gasoline   Motor vehicle emissions contribute to air pollution and are a major ingredient in the creation of smog in some large cities . A 2013 study by MIT indicates that 53,000 early deaths occur per year in the United States alone because of vehicle emissions . According to another study from the same university , traffic fumes alone cause the death of 5,000 people every year just in the United Kingdom .


Exoplanet

An exoplanet ( -LSB- ˈɛk.səʊˌplæn.ɪt -RSB- , -LSB- ˌɛk.soʊˈplæn.ɪt -RSB- ) or extrasolar planet is a planet outside of our solar system that orbits a star . The first scientific detection of an exoplanet was in 1988 . However , the first confirmed detection came in 1992 ; since then , and as of , there have been exoplanets , in planetary systems and multiple planetary systems , confirmed detections .   HARPS ( since 2004 ) has discovered about a hundred exoplanets while the Kepler space telescope ( since 2009 ) has found more than two thousand . Kepler has also detected a few thousand candidate planets , of which about 11 % may be false positives .  On average , there is at least one planet per star , with a percentage having multiple planets .  About 1 in 5 Sun-like starsFor the purpose of this 1 in 5 statistic , `` Sun-like '' means G-type star . Data for Sun-like stars was not available so this statistic is an extrapolation from data about K-type stars have an `` Earth-sized `` For the purpose of this 1 in 5 statistic , Earth-sized means 1 -- 2 Earth radii planet in the habitable zone.For the purpose of this 1 in 5 statistic , `` habitable zone '' means the region with 0.25 to 4 times Earth 's stellar flux ( corresponding to 0.5 -- 2 AU for the Sun ) . Assuming there are 200 billion stars in the Milky Way , About 1/4 of stars are GK Sun-like stars . The number of stars in the galaxy is not accurately known , but assuming 200 billion stars in total , the Milky Way would have about 50 billion Sun-like ( GK ) stars , of which about 1 in 5 ( 22 % ) or 11 billion would be Earth-sized in the habitable zone . Including red dwarfs would increase this to 40 billion . one can hypothesize that there are 11 billion potentially habitable Earth-sized planets in the Milky Way , rising to 40 billion if planets orbiting the numerous red dwarfs are included .   The least massive planet known is Draugr ( also known as PSR B1257 +12 A or PSR B1257 +12 b ) , which is about twice the mass of the Moon . The most massive planet listed on the NASA Exoplanet Archive is DENIS-P J082303.1-491201 b , about 29 times the mass of Jupiter , although according to some definitions of a planet , it is too massive to be a planet and may be a brown dwarf instead . There are planets that are so near to their star that they take only a few hours to orbit and there are others so far away that they take thousands of years to orbit . Some are so far out that it is difficult to tell whether they are gravitationally bound to the star . Almost all of the planets detected so far are within the Milky Way , but there have also been a few possible detections of extragalactic planets . The nearest exoplanet is Proxima Centauri b , located 4.2 light-years ( 1.3 parsecs ) from Earth and orbiting Proxima Centauri , the closest star to the Sun .   The discovery of exoplanets has intensified interest in the search for extraterrestrial life . There is special interest in planets that orbit in a star 's habitable zone , where it is possible for liquid water , a prerequisite for life on Earth , to exist on the surface . The study of planetary habitability also considers a wide range of other factors in determining the suitability of a planet for hosting life .   Besides exoplanets , there are also rogue planets , which do not orbit any star and which tend to be considered separately , especially if they are gas giants , in which case they are often counted , like WISE 0855 − 0714 , as sub-brown dwarfs . The rogue planets in the Milky Way possibly number in the billions ( or more ) .


Explosive

An explosion is a rapid expansion in volume associated with an extremely vigorous outward release of energy, usually with the generation of high temperatures and release of high-pressure gases.  Supersonic explosions created by high explosives are known as detonations and travel via shock waves.  Subsonic explosions are created by low explosives through a slower combustion process known as deflagration.


Externality

In economics , an externality is the cost or benefit that affects a party who did not choose to incur that cost or benefit . Economists often urge governments to adopt policies that `` internalize '' an externality , so that costs and benefits will affect mainly parties who choose to incur them .   For example , manufacturing activities that cause air pollution impose health and clean-up costs on the whole society , whereas the neighbors of an individual who chooses to fire-proof his home may benefit from a reduced risk of a fire spreading to their own houses . If external costs exist , such as pollution , the producer may choose to produce more of the product than would be produced if the producer were required to pay all associated environmental costs . Because responsibility or consequence for self-directed action lies partly outside the self , an element of externalization is involved . If there are external benefits , such as in public safety , less of the good may be produced than would be the case if the producer were to receive payment for the external benefits to others . For the purpose of these statements , overall cost and benefit to society is defined as the sum of the imputed monetary value of benefits and costs to all parties involved . Thus , unregulated markets in goods or services with significant externalities generate prices that do not reflect the full social cost or benefit of their transactions ; such markets are therefore inefficient .


Extinction

In biology and ecology , extinction is the end of an organism or of a group of organisms ( taxon ) , normally a species . The moment of extinction is generally considered to be the death of the last individual of the species , although the capacity to breed and recover may have been lost before this point . Because a species ' potential range may be very large , determining this moment is difficult , and is usually done retrospectively . This difficulty leads to phenomena such as Lazarus taxa , where a species presumed extinct abruptly `` reappears '' ( typically in the fossil record ) after a period of apparent absence .   More than 99 percent of all species , amounting to over five billion species , that ever lived on Earth are estimated to be extinct . Estimates on the number of Earth 's current species range from 10 million to 14 million , of which about 1.2 million have been documented and over 86 percent have not yet been described . More recently , in May 2016 , scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described .   Through evolution , species arise through the process of speciation -- where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche -- and species become extinct when they are no longer able to survive in changing conditions or against superior competition . The relationship between animals and their ecological niches has been firmly established . A typical species becomes extinct within 10 million years of its first appearance , although some species , called living fossils , survive with virtually no morphological change for hundreds of millions of years .   Mass extinctions are relatively rare events ; however , isolated extinctions are quite common . Only recently have extinctions been recorded and scientists have become alarmed at the current high rate of extinctions . Most species that become extinct are never scientifically documented . Some scientists estimate that up to half of presently existing plant and animal species may become extinct by 2100 .   A dagger symbol next to a species name is often used to indicate its extinction .


Extinction event

An extinction event ( also known as a mass extinction or biotic crisis ) is a widespread and rapid decrease in the biodiversity on Earth . Such an event is identified by a sharp change in the diversity and abundance of multicellular organisms . It occurs when the rate of extinction increases with respect to the rate of speciation . Because the majority of diversity and biomass on Earth is microbial , and thus difficult to measure , recorded extinction events affect the easily observed , biologically complex component of the biosphere rather than the total diversity and abundance of life .   Extinction occurs at an uneven rate . Based on the fossil record , the background rate of extinctions on Earth is about two to five taxonomic families of marine animals every million years . Marine fossils are mostly used to measure extinction rates because of their superior fossil record and stratigraphic range compared to land animals .   The Great Oxygenation Event was probably the first major extinction event . Since the Cambrian explosion five further major mass extinctions have significantly exceeded the background extinction rate . The most recent and debatably best-known , the Cretaceous -- Paleogene extinction event , which occurred approximately million years ago ( Ma ) , was a large-scale mass extinction of animal and plant species in a geologically short period of time . In addition to the five major mass extinctions , there are numerous minor ones as well , and the ongoing mass extinction caused by human activity is sometimes called the sixth extinction . Mass extinctions seem to be a mainly Phanerozoic phenomenon , with extinction rates low before large complex organisms arose .   Estimates of the number of major mass extinctions in the last 540 million years range from as few as five to more than twenty . These differences stem from the threshold chosen for describing an extinction event as `` major '' , and the data chosen to measure past diversity .


Extinction risk from global warming

The extinction risk of global warming is the risk of species becoming extinct due to the effects of global warming .


Extraterrestrial atmosphere

The study of extraterrestrial atmospheres is an active field of research , both as an aspect of astronomy and to gain insight into Earth 's atmosphere . In addition to Earth , many of the other astronomical objects in the Solar System have atmospheres . These include all the gas giants , as well as Mars , Venus , and Pluto . Several moons and other bodies also have atmospheres , as do comets and the Sun . There is evidence that extrasolar planets can have an atmosphere . Comparisons of these atmospheres to one another and to Earth 's atmosphere broaden our basic understanding of atmospheric processes such as the greenhouse effect , aerosol and cloud physics , and atmospheric chemistry and dynamics .


Extratropical cyclone

Extratropical cyclones , sometimes called mid-latitude cyclones or wave cyclones , are low-pressure areas which , along with the anticyclones of high-pressure areas , drive the weather over much of the Earth . Extratropical cyclones are capable of producing anything from cloudiness and mild showers to heavy gales , thunderstorms , blizzards , and tornadoes . These types of cyclones are defined as large scale ( synoptic ) low pressure weather systems that occur in the middle latitudes of the Earth . In contrast with tropical cyclones , extratropical cyclones produce rapid changes in temperature and dew point along broad lines , called weather fronts , about the center of the cyclone .


Extreme weather

Extreme weather includes unexpectable , unusual , unpredictable severe or unseasonal weather ; weather at the extremes of the historical distribution -- the range that has been seen in the past . Often , extreme events are based on a location 's recorded weather history and defined as lying in the most unusual ten percent . In recent years some extreme weather events have been attributed to human-induced global warming , with studies indicating an increasing threat from extreme weather in the future .


Fahrenheit

Fahrenheit is a temperature scale based on one proposed in 1724 by Amsterdam-based physicist Daniel Gabriel Fahrenheit ( 1686 -- 1736 ) , after whom the scale is named . It uses the degree Fahrenheit ( symbol ° F ) as the unit . Several accounts of how he originally defined his scale exist . The lower defining point , 0 ° F , was established as the temperature of a solution of brine made from equal parts of ice and salt . Further limits were established as the melting point of ice ( 32 ° F ) and his best estimate of the average human body temperature ( 96 ° F , about 2.6 ° F less than the modern value due to a later redefinition of the scale ) . The scale is now usually defined by two fixed points : the temperature at which water freezes into ice is defined as 32 ° F , and the boiling point of water is defined to be 212 ° F , a 180 ° F separation , as defined at sea level and standard atmospheric pressure .   By the end of the 20th century , Fahrenheit was used as the official temperature scale only in the United States ( including its unincorporated territories ) , its freely associated states in the Western Pacific ( Palau , the Federated States of Micronesia and the Marshall Islands ) , the Bahamas , Belize , and the Cayman Islands . All other countries in the world now use the Celsius scale , defined since 1954 by absolute zero being − 273.15 ° C and the triple point of water being at 0.01 ° C.


Falsifiability

Falsifiability or refutability of a statement , hypothesis , or theory is the inherent possibility that it can be proven false . A statement is called falsifiable if it is possible to conceive of an observation or an argument which negates the statement in question . In this sense , falsify is synonymous with nullify , meaning to invalidate or `` show to be false '' .   For example , by the problem of induction , no number of confirming observations can verify a universal generalization , such as All swans are white , since it is logically possible to falsify it by observing a single black swan . Thus , the term falsifiability is sometimes synonymous to testability . Some statements , such as It will be raining here in one million years , are falsifiable in principle , but not in practice .   The concern with falsifiability gained attention by way of philosopher of science Karl Popper 's scientific epistemology `` falsificationism '' . Popper stresses the problem of demarcation -- distinguishing the scientific from the unscientific -- and makes falsifiability the demarcation criterion , such that what is unfalsifiable is classified as unscientific , and the practice of declaring an unfalsifiable theory to be scientifically true is pseudoscience .


Famine

A famine is a widespread scarcity of food , caused by several factors including crop failure , population imbalance , or government policies . This phenomenon is usually accompanied or followed by regional malnutrition , starvation , epidemic , and increased mortality . Every inhabited continent in the world has experienced a period of famine throughout history . In the 19th and 20th century , it was generally Eastern Europe and Asia that suffered the most deaths from famine . The numbers dying from famine began to fall sharply from the 1970s .   Some countries , particularly in sub-Saharan Africa , continue to have extreme cases of famine . Since 2010 , Africa has been the most affected continent in the world . As of 2017 , the United Nations has warned some 20 million are at risk in South Sudan , Somalia , Nigeria and Yemen . Agricultural conditions have been fluctuating more and more due to variations in weather , and the distribution of food has been affected by conflict . Most programmes now direct their aid towards Africa .


Farleigh Hungerford Castle

Farleigh Hungerford Castle , sometimes called Farleigh Castle or Farley Castle , is a medieval castle in Farleigh Hungerford , Somerset , England . The castle was built in two phases : the inner court was constructed between 1377 and 1383 by Sir Thomas Hungerford , who made his fortune working as a steward to John of Gaunt . The castle was built to a quadrangular design , already slightly old-fashioned , on the site of an existing manor house overlooking the River Frome . A park was attached to the castle , requiring the destruction of a local village . His son , Sir Walter Hungerford , a successful knight and courtier to Henry V , became rich during the Hundred Years War with France and extended the castle with an additional , outer court , enclosing the parish church in the process . By Walter 's death in 1449 , the substantial castle was richly appointed and its chapel decorated with murals .   The castle largely remained in the hands of the Hungerford family over the next two centuries , despite periods during the War of the Roses in which it was held by the Crown following the attainder and execution of members of the family . At the outbreak of the English Civil War in 1642 , the castle , modernized to the latest Tudor and Stuart fashions , was held by Sir Edward Hungerford . Edward declared his support for Parliament , becoming a leader of the Roundheads in Wiltshire . Farleigh Hungerford was seized by Royalist forces in 1643 , but recaptured by Parliament without a fight near the end of the conflict in 1645 . As a result , it escaped slighting following the war , unlike many other castles in the south-west of England .   The last member of the Hungerford family to hold the castle , Sir Edward Hungerford , inherited it in 1657 , but his gambling and expensive living forced him to sell the property in 1686 . By the 18th century the castle was no longer lived in by its owners and fell into disrepair ; in 1730 it was bought by the Houlton family , when much of it was broken up for salvage . Antiquarian and tourist interest in the now ruined castle increased through the 18th and 19th centuries . The castle chapel was repaired in 1779 and became a museum of curiosities , complete with the murals rediscovered on its walls in 1844 and a number of rare lead anthropomorphic coffins from the mid-17th century . In the 1915 Farleigh Hungerford Castle was sold to the Office of Works and a controversial restoration programme began . It is now owned by English Heritage , who operate it as a tourist attraction , and the castle is a Grade I listed building and a Scheduled Ancient Monument .


February 8


Fertilizer

A fertilizer ( American English ) or fertiliser ( British English ; see spelling differences ) is any material of natural or synthetic origin ( other than liming materials ) that is applied to soils or to plant tissues ( usually leaves ) to supply one or more plant nutrients essential to the growth of plants .


Field hockey

Field hockey is a team sport of the hockey family . The earliest origins of the game date back to the Middle Ages in England , Scotland , France and the Netherlands . The game can be played on a grass field or a turf field as well as an indoor board surface . Each team plays with eleven players , including the goalie . Players use sticks made out of wood , carbon fibre , fibre glass or a combination of carbon fibre and fibre glass in different quantities ( with the higher carbon fibre stick being more expensive and less likely to break ) to hit a round , hard , plastic ball . The length of the stick depends on the player 's individual height . Only one end of the stick is allowed to be used . Goalies often have a different kind of stick , however they can also use an ordinary field hockey stick . The specific goal-keeping sticks have another curve at the end of the stick , this is to give them more surface area to save the ball . The uniform consists of shin guards , shoes , shorts , a mouth guard and a jersey . Today , the game is played globally , with particular popularity throughout Western Europe , the Indian subcontinent , Southern Africa , Australia , New Zealand , Argentina , and parts of the United States ( primarily New England and the Mid-Atlantic states ) . Field Hockey is the national game of Pakistan . The term `` field hockey '' is used primarily in Canada and the United States where ice hockey is more popular . In Sweden the term `` landhockey '' is used and to some degree also in Norway . It is a section of Norway 's Bandy Association . Until recently they called it `` hockey '' , when it was changed to `` landhockey '' .   During play , goal keepers are the only players who are allowed to touch the ball with any part of their body ( the player 's hand is considered ` part of the stick ' if on the stick ) , while field players play the ball with the flat side of their stick . Goal keepers also can not play the ball with the back of their stick . Whoever scores the most goals by the end of the match wins . If the score is tied at the end of the game , either a draw is declared or the game goes into extra time or a penalty shootout , depending on the competition 's format . There are many variations to overtime play that depend on the league and tournament play . In college play , a seven-aside overtime period consists of a 10-minute golden goal period with seven players for each team . If a tie still remains , the game enters a one-on-one competition where each team chooses 5 players to dribble from the 25 yard line down to the circle against the opposing goalie . The player has 8 seconds to score on the goalie keeping it in bounds . The play ends after a goal is scored , the ball goes out of bounds , a foul is committed ( ending in either a penalty stroke or flick or the end of the one on one ) or time expires . If the tie still persists extra rounds thereafter until one team has scored .   The governing body of hockey is the International Hockey Federation ( FIH , in French ) , with men and women being represented internationally in competitions including the Olympic Games , World Cup , World League , Champions Trophy and Junior World Cup , with many countries running extensive junior , senior , and masters club competitions . The FIH is also responsible for organising the Hockey Rules Board and developing the rules for the game .   A popular variant of field hockey is indoor field hockey , which differs in a number of respects while embodying the primary principles of hockey . Indoor hockey is a 5-a-side variant , with a field which is reduced to approximately 40 x. With many of the rules remaining the same , including obstruction and feet , there are several key variations : Players may not raise the ball unless shooting on goal , players may not hit the ball ( instead using pushes to transfer the ball ) , and the sidelines are replaced with solid barriers which the ball will rebound off .


Figure of the Earth

The expression figure of the Earth has various meanings in geodesy according to the way it is used and the precision with which the Earth 's size and shape is to be defined . While the sphere is a close approximation of the true figure of the Earth and satisfactory for many purposes , geodesists have developed several models that more closely approximate the shape of the Earth so that coordinate systems can serve the precise needs of navigation , surveying , cadastre , land use , and diverse other concerns .


Financial crisis of 2007–08

The financial crisis of 2007–2008, also known as the global financial crisis (GFC), was a severe worldwide financial crisis. Excessive risk-taking by banks combined with the bursting of the United States housing bubble caused the values of securities tied to U.S. real estate to plummet, damaging financial institutions globally, culminating with the bankruptcy of Lehman Brothers on September 15, 2008, and an international banking crisis. The crisis sparked the Great Recession, which, at the time, was the most severe global recession since the Great Depression. It was also followed by the European debt crisis, which began with a deficit in Greece in late 2009, and the 2008–2011 Icelandic financial crisis, which involved the bank failure of all three of the major banks in Iceland and, relative to the size of its economy, was the largest economic collapse suffered by any country in economic history. It was among the five worst financial crises the world had experienced and led to a loss of more than $2 trillion from the global economy.U.S. home mortgage debt relative to GDP increased from an average of 46% during the 1990s to 73% during 2008, reaching $10.5 trillion. The increase in cash out refinancings, as home values rose, fueled an increase in consumption that could no longer be sustained when home prices declined. Many financial institutions owned investments whose value was based on home mortgages such as mortgage-backed securities, or credit derivatives used to insure them against failure, which declined in value significantly. The International Monetary Fund estimated that large U.S. and European banks lost more than $1 trillion on toxic assets and from bad loans from January 2007 to September 2009.Lack of investor confidence in bank solvency and declines in credit availability led to plummeting stock and commodity prices in late 2008 and early 2009. The crisis rapidly spread into a global economic shock, resulting in several bank failures. Economies worldwide slowed during this period since credit tightened and international trade declined. Housing markets suffered and unemployment soared, resulting in evictions and foreclosures. Several businesses failed. From its peak in the second quarter of 2007 at $64.4 trillion, household wealth in the United States fell $14 trillion, to $50.4 trillion by the end of the first quarter of 2009, resulting in a decline in consumption, then a decline in business investment. In the fourth quarter of 2008, the quarter-over-quarter decline in real GDP in the U.S. was 8.4%. The U.S. unemployment rate peaked at 10.0% in October 2009, the highest rate since 1983 and roughly twice the pre-crisis rate. The average hours per work week declined to 33, the lowest level since the government began collecting the data in 1964.The economic crisis started in the U.S. but spread to the rest of the world. U.S. consumption accounted for more than a third of the growth in global consumption between 2000 and 2007 and the rest of the world depended on the U.S. consumer as a source of demand. Toxic securities were owned by corporate and institutional investors globally. Derivatives such as credit default swaps also increased the linkage between large financial institutions. The de-leveraging of financial institutions, as assets were sold to pay back obligations that could not be refinanced in frozen credit markets, further accelerated the solvency crisis and caused a decrease in international trade. Reductions in the growth rates of developing countries were due to falls in trade, commodity prices, investment and remittances sent from migrant workers. This led to a dramatic rise in the number of households living below the poverty line. States with fragile political systems feared that investors from Western states would withdraw their money because of the crisis.As part of national fiscal policy response to the Great Recession, governments and central banks, including the Federal Reserve, the European Central Bank and the Bank of England, provided then-unprecedented trillions of dollars in bailouts and stimulus, including expansive fiscal policy and monetary policy to offset the decline in consumption and lending capacity, avoid a further collapse, encourage lending, restore faith in the integral commercial paper markets, avoid the risk of a deflationary spiral, and provide banks with enough funds to allow customers to make withdrawals. In effect, the central banks went from being the "lender of last resort" to the "lender of only resort" for a significant portion of the economy. In some cases the Fed was considered the "buyer of last resort". During the fourth quarter of 2008, these central banks purchased US$2.5 trillion of government debt and troubled private assets from banks. This was the largest liquidity injection into the credit market, and the largest monetary policy action in world history. Following a model initiated by the 2008 United Kingdom bank rescue package, the governments of European nations and the United States guaranteed the debt issued by their banks and raised the capital of their national banking systems, ultimately purchasing $1.5 trillion newly issued preferred stock in major banks. The Federal Reserve created then-significant amounts of new currency as a method to combat the liquidity trap.Bailouts came in the form of trillions of dollars of loans, asset purchases, guarantees, and direct spending. Significant controversy accompanied the bailouts, such as in the case of the AIG bonus payments controversy, leading to the development of a variety of "decision making frameworks", to help balance competing policy interests during times of financial crisis. Alistair Darling, the U.K.'s Chancellor of the Exchequer at the time of the crisis, stated in 2018 that Britain came within hours of "a breakdown of law and order" the day that Royal Bank of Scotland was bailed-out.Instead of financing more domestic loans, some banks instead spent some of the stimulus money in more profitable areas such as investing in emerging markets and foreign currencies.In July 2010, the Dodd–Frank Wall Street Reform and Consumer Protection Act was enacted in the United States to "promote the financial stability of the United States". The Basel III capital and liquidity standards were adopted worldwide. Since the 2008 financial crisis, consumer regulators in America have more closely supervised sellers of credit cards and home mortgages in order to deter anticompetitive practices that led to the crisis. At least two major reports on the causes of the crisis were produced by the U.S. Congress: the Financial Crisis Inquiry Commission report, released January 2011, and a report by the United States Senate Homeland Security Permanent Subcommittee on Investigations entitled Wall Street and the Financial Crisis: Anatomy of a Financial Collapse, released April 2011.  In total, 47 bankers served jail time as a result of the crisis, over half of which were from Iceland, where the crisis was the most severe and led to the collapse of all 3 of the major Icelandic banks. In April 2012, Geir Haarde of Iceland became the only politician to be convicted as a result of the crisis. Only one banker in the United States served jail time as a result of the crisis, Kareem Serageldin, a banker at Credit Suisse who was sentenced to 30 months in jail and returned $25.6 million in compensation for manipulating bond prices to hide $1 billion of losses. No individuals in the United Kingdom were convicted as a result of the crisis. Goldman Sachs paid $550 million to settle fraud charges after allegedly anticipating the crisis and selling toxic investments to its clients.With fewer resources to risk in creative destruction, the number of patent applications was flat, compared exponential increases in patent application in prior years.  Typical American families did not fare well, nor did those "wealthy-but-not-wealthiest" families just beneath the pyramid's top. However, half of the poorest families did not have wealth declines at all during the crisis because they generally did not own financial investments whose value fluctuates. The Federal Reserve surveyed 4,000 households between 2007 and 2009, and found that the total wealth of 63% of all Americans declined in that period and 77% of the richest families had a decrease in total wealth, while only 50% of those on the bottom of the pyramid suffered a decrease.


First 100 days of Donald Trump's presidency

The first 100 days of Donald Trump 's presidency began with his inauguration as the 45th President of the United States , which occurred at noon on January 20 , 2017 . The 48th Vice President of the United States , Mike Pence , was inaugurated on the same day . The 100th day of Trump 's presidency was April 29 , 2017 . Trump first announced his plan for the first hundred days of his presidency in Gettysburg , Pennsylvania , on October 23 , 2016 , before the election .   One of Trump 's major accomplishments , made as part of a `` 100-day pledge '' , was the confirmation of Neil Gorsuch as an Associate Justice of the Supreme Court of the United States . Structurally , President Trump had the advantage of a Republican Party majority in the U.S. House of Representatives and the Senate , but was unable to fulfill his major pledges in his first 100 days and had an approval rating of between 40 and 42 percent , `` the lowest for any first-term president at this point in his tenure '' . Although he tried to make progress on one of his key economic policies -- the dismantling of the Dodd -- Frank Wall Street Reform and Consumer Protection Act -- his failure to repeal the Patient Protection and Affordable Care Act ( ACA ) in the first 100 days was a major setback . He reversed his position on a number of issues including labeling China as a currency manipulator , NATO , launching the 2017 Shayrat missile strike without congressional approval , the North American Free Trade Agreement ( NAFTA ) , renomination of Janet Yellen as Chair of the Federal Reserve , and the nomination of Export-Import Bank directors . Supporters claimed that as the first to have been elected President in present times who has held neither military or political office , he therefore faced a steep learning curve . Trump 's approval among his base was high , with 96 % of those who voted for him saying in an April 2017 poll that they would vote for him again .   Near the end of the 100 days , the Trump administration introduced a broad outline of a sweeping tax reform focusing on deep tax cuts . While it is intended to encourage economic growth , there were concerns from some members of the United States Congress about raising the national deficit . In spite of the sharp decline in gross domestic product ( GDP ) in the first quarter of 2017 -- representing the weakest quarterly economic growth in three years -- the S&P 500 was near an all-time high , representing a 12 % rise from the first quarter of 2016 , as investor confidence remained elevated . Although Trump had to concede to delay funding for the U.S. -- Mexico border wall he had promised , narrowly avoiding a government shutdown a few days before the end of the first 100 days , his rhetoric may have contributed to a sharp drop in the number of illegal crossings at the Mexico -- United States border .   Trump signed 24 executive orders in his first 100 days , the most executive orders of any President since World War II . He also signed 22 presidential memoranda , 20 presidential proclamations , and 28 bills . About a dozen of those bills roll-back regulations finalized during the last months of his immediate predecessor Barack Obama 's presidency using the Congressional Review Act . Most of the other bills are `` small-scale measures that appoint personnel , name federal facilities or modify existing programs . '' None of Trump 's bills are considered to be `` major bills '' -- based on a `` longstanding political-science standard for ` major bills ' . '' Presidential historian Michael Beschloss said that `` based on a legislative standard '' -- which is what the first 100 days has been judged on since the tenure of President Franklin Roosevelt , who enacted 76 laws in 100 days including nine that were `` major '' -- `` Trump is really pretty low down on the list . ''


Fisheries and climate change

Rising ocean temperatures and ocean acidification are radically altering aquatic ecosystems . Climate change is modifying fish distribution and the productivity of marine and freshwater species . This has impacts on the sustainability of fisheries and aquaculture , on the livelihoods of the communities that depend on fisheries , and on the ability of the oceans to capture and store carbon ( biological pump ) . The effect of sea level rise means that coastal fishing communities are in the front line of climate change , while changing rainfall patterns and water use impact on inland ( freshwater ) fisheries and aquaculture .


Flood

A flood is an overflow of water that submerges land that is usually dry . The European Union ( EU ) Floods Directive defines a flood as a covering by water of land not normally covered by water . In the sense of `` flowing water '' , the word may also be applied to the inflow of the tide .   Flooding may occur as an overflow of water from water bodies , such as a river , lake , or ocean , in which the water overtops or breaks levees , resulting in some of that water escaping its usual boundaries , or it may occur due to an accumulation of rainwater on saturated ground in an areal flood . While the size of a lake or other body of water will vary with seasonal changes in precipitation and snow melt , these changes in size are unlikely to be considered significant unless they flood property or drown domestic animals .   Floods can also occur in rivers when the flow rate exceeds the capacity of the river channel , particularly at bends or meanders in the waterway . Floods often cause damage to homes and businesses if they are in the natural flood plains of rivers . While riverine flood damage can be eliminated by moving away from rivers and other bodies of water , people have traditionally lived and worked by rivers because the land is usually flat and fertile and because rivers provide easy travel and access to commerce and industry .   Some floods develop slowly , while others such as flash floods , can develop in just a few minutes and without visible signs of rain . Additionally , floods can be local , impacting a neighborhood or community , or very large , affecting entire river basins .