Query: CO2 does not cause climate change, it RESPONDS to it [...]

Relevant passages:
Scientific consensus on climate change <=SEP=> There is currently a strong scientific consensus that the Earth is warming and that this warming is mainly caused by human activities. This consensus is supported by various studies of scientists' opinions and by position statements of scientific organizations, many of which explicitly agree with the Intergovernmental Panel on Climate Change (IPCC) synthesis reports.  Nearly all actively publishing climate scientists (97–98%) support the consensus on anthropogenic climate change, and the remaining 2% of contrarian studies either cannot be replicated or contain errors.

Carbon dioxide <=SEP=> Carbon dioxide ( chemical formula ) is a colorless gas with a density about 60 % higher than that of air ( 1.225 g/L ) that is odorless at normally encountered concentrations . Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms . It occurs naturally in Earth 's atmosphere as a trace gas at a concentration of about 0.04 percent ( 400 ppm ) by volume . Natural sources include volcanoes , hot springs and geysers , and it is freed from carbonate rocks by dissolution in water and acids . Because carbon dioxide is soluble in water , it occurs naturally in groundwater , rivers and lakes , ice caps , glaciers and seawater . It is present in deposits of petroleum and natural gas .   As the source of available carbon in the carbon cycle , atmospheric carbon dioxide is the primary carbon source for life on Earth and its concentration in Earth 's pre-industrial atmosphere since late in the Precambrian has been regulated by photosynthetic organisms and geological phenomena . Plants , algae and cyanobacteria use light energy to photosynthesize carbohydrate from carbon dioxide and water , with oxygen produced as a waste product .   Carbon dioxide is produced by all aerobic organisms when they metabolize carbohydrates and lipids to produce energy by respiration . It is returned to water via the gills of fish and to the air via the lungs of air-breathing land animals , including humans . Carbon dioxide is produced during the processes of decay of organic materials and the fermentation of sugars in bread , beer and winemaking . It is produced by combustion of wood and other organic materials and fossil fuels such as coal , peat , petroleum and natural gas .   It is a versatile industrial material , used , for example , as an inert gas in welding and fire extinguishers , as a pressurizing gas in air guns and oil recovery , as a chemical feedstock and in liquid form as a solvent in decaffeination of coffee and supercritical drying . It is added to drinking water and carbonated beverages including beer and sparkling wine to add effervescence . The frozen solid form of , known as `` dry ice '' is used as a refrigerant and as an abrasive in dry-ice blasting .   Carbon dioxide is the most significant long-lived greenhouse gas in Earth 's atmosphere . Since the Industrial Revolution anthropogenic emissions - primarily from use of fossil fuels and deforestation - have rapidly increased its concentration in the atmosphere , leading to global warming . Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid .

Climate change adaptation <=SEP=> Climate change adaptation is a response to global warming and climate change , that seeks to reduce the vulnerability of social and biological systems to relatively sudden change and thus offset the effects of global warming . Even if emissions are stabilized relatively soon , global warming and its effects will last many years , and adaptation will be necessary to the resulting changes in climate . Adaptation is especially important in developing countries since those countries are predicted to bear the brunt of the effects of global warming . That is , the capacity and potential for humans to adapt ( called adaptive capacity ) is unevenly distributed across different regions and populations , and developing countries generally have less capacity to adapt ( Schneider et al. , 2007 ) . Furthermore , the degree of adaptation correlates to the situational focus on environmental issues . Therefore , adaptation requires the situational assessment of sensitivity and vulnerability to environmental impacts . Adaptive capacity is closely linked to social and economic development ( IPCC , 2007 ) . The economic costs of adaptation to climate change are likely to cost billions of dollars annually for the next several decades , though the amount of money needed is unknown . Donor countries promised an annual $ 100 billion by 2020 through the Green Climate Fund for developing countries to adapt to climate change . However , while the fund was set up during COP16 in Cancún , concrete pledges by developed countries have not been forthcoming . The adaptation challenge grows with the magnitude and the rate of climate change .   Another response to climate change , known as climate change mitigation ( Verbruggen , 2007 ) is to reduce greenhouse gas ( GHG ) emissions and/or enhance the removal of these gases from the atmosphere ( through carbon sinks ) . Even the most effective reductions in emissions , however , would not prevent further climate change impacts , making the need for adaptation unavoidable ( Klein et al. , 2007 ) . In a literature assessment , Klein et al. ( 2007 ) assessed options for adaptation . They concluded , with very high confidence , that in the absence of mitigation efforts , the effects of climate change would reach such a magnitude as to make adaptation impossible for some natural ecosystems . Others are concerned that climate adaptation programs might interfere with the existing development programs and thus lead to unintended consequences for vulnerable groups . For human systems , the economic and social costs of unmitigated climate change would be very high .

Greenhouse gas <=SEP=> A greenhouse gas ( abbrev . GHG ) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range . This process is the fundamental cause of the greenhouse effect . The primary greenhouse gases in Earth 's atmosphere are water vapor , carbon dioxide , methane , nitrous oxide , and ozone . Without greenhouse gases , the average temperature of Earth 's surface would be about -18 ° C , rather than the present average of 15 ° C . In the Solar System , the atmospheres of Venus , Mars and Titan also contain gases that cause a greenhouse effect .   Human activities since the beginning of the Industrial Revolution ( taken as the year 1750 ) have produced a 40 % increase in the atmospheric concentration of carbon dioxide , from 280 ppm in 1750 to 406 ppm in early 2017 . This increase has occurred despite the uptake of a large portion of the emissions by various natural `` sinks '' involved in the carbon cycle . Anthropogenic carbon dioxide emissions ( i.e. , emissions produced by human activities ) come from combustion of fossil fuels , principally coal , oil , and natural gas , along with deforestation , soil erosion and animal agriculture .   It has been estimated that if greenhouse gas emissions continue at the present rate , Earth 's surface temperature could exceed historical values as early as 2047 , with potentially harmful effects on ecosystems , biodiversity and the livelihoods of people worldwide . Recent estimates suggest that on the current emissions trajectory the Earth could pass a threshold of 2 ° C global warming , which the United Nations ' IPCC designated as the upper limit to avoid `` dangerous '' global warming , by 2036 .