Query: The final amount of extra CO2 that remains in the atmosphere stays there on a time scale of centuries.

Relevant passages:
Carbon price <=SEP=> Carbon pricing -- the method favored by many economists for reducing global-warming emissions -- charges those who emit carbon dioxide ( CO2 ) for their emissions . That charge , called a carbon price , is the amount that must be paid for the right to emit one tonne of CO2 into the atmosphere . Carbon pricing usually takes the form either of a carbon tax or a requirement to purchase permits to emit , generally known as cap-and-trade , but also called `` allowances '' .   Carbon pricing solves the economic problem that , a known greenhouse gas , is what economics calls a negative externality -- a detrimental product that is not priced ( charged for ) by any market . As a consequence of not being priced , there is no market mechanism responsive to the costs of CO2 emitted . The standard economic solution to problems of this type , first proposed by Arthur Pigou in 1920 , is for the product - in this case , CO2 emissions - to be charged at a price equal to the monetary value of the damage caused by the emissions . This should result in the economically optimal ( efficient ) amount of CO2 emissions . Many practical concerns mar the theoretical simplicity of this picture : for example , the exact monetary damage caused by a tonne of CO2 is uncertain .   The economics of carbon pricing is much the same for taxes and cap-and-trade . Both prices are efficient ; they have the same social cost and the same effect on profits if permits are auctioned . However , some economists argue that caps prevent non-price policies , such as renewable energy subsidies , from reducing carbon emissions , while carbon taxes do not . Others argue that an enforced cap is the only way to guarantee that carbon emissions will actually be reduced ; a carbon tax will not prevent those who can afford to do so from continuing to generate emissions .   The choice of pricing approach , a tax or cap-and-trade , has been controversial . A carbon tax is generally favored on economic grounds for its simplicity and stability , while cap-and-trade is often favored on political grounds . Recently ( 2013 − 14 ) economic opinion has been shifting more heavily toward taxes as national policy measures , and toward a neutral carbon-price-commitment position for the purpose of international climate negotiations .

Petroleum <=SEP=> Petroleum ( from petra #Greek : `` rock '' + oleum #Latin : `` oil '' . ) is a naturally occurring , yellow-to-black liquid found in geological formations beneath the Earth 's surface , which is commonly refined into various types of fuels . Components of petroleum are separated using a technique called fractional distillation .   It consists of hydrocarbons of various molecular weights and other organic compounds . The name petroleum covers both naturally occurring unprocessed crude oil and petroleum products that are made up of refined crude oil . A fossil fuel , petroleum is formed when large quantities of dead organisms , usually zooplankton and algae , are buried underneath sedimentary rock and subjected to both intense heat and pressure .   Petroleum has mostly been recovered by oil drilling ( natural petroleum springs are rare ) . Drilling is carried out after studies of structural geology ( at the reservoir scale ) , sedimentary basin analysis , and reservoir characterization ( mainly in terms of the porosity and permeability of geologic reservoir structures ) have been completed . It is refined and separated , most easily by distillation , into a large number of consumer products , from gasoline ( petrol ) and kerosene to asphalt and chemical reagents used to make plastics and pharmaceuticals . Petroleum is used in manufacturing a wide variety of materials , and it is estimated that the world consumes about 95 million barrels each day .   Concern over the depletion of the earth 's finite reserves of oil , and the effect this would have on a society dependent on it , is a concept known as peak oil . The use of fossil fuels , such as petroleum , will have a negative impact on Earth 's biosphere , damaging ecosystems through events such as oil spills and releasing a range of pollutants into the air including ground-level ozone and sulfur dioxide from sulfur impurities in fossil fuels . The burning of fossil fuels plays the major role in the current episode of global warming .

Global warming <=SEP=> Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years .   In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing .   Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years .   Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) ,  whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change .   Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned .