Query: contrary to the hypothesis that rising temperature is caused by increasing CO2.

Relevant passages:
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 .

Fred Singer <=SEP=> Siegfried Fred Singer ( born September 27 , 1924 ) is an Austrian-born American physicist and emeritus professor of environmental science at the University of Virginia . Singer trained as an atmospheric physicist and is known for his work in space research , atmospheric pollution , rocket and satellite technology , his questioning of the link between UV-B and melanoma rates , and that between CFCs and stratospheric ozone loss , his public downplaying of the health risks of passive smoking , and as an advocate for climate change denial . He is the author or editor of several books including Global Effects of Environmental Pollution ( 1970 ) , The Ocean in Human Affairs ( 1989 ) , Global Climate Change ( 1989 ) , The Greenhouse Debate Continued ( 1992 ) , and Hot Talk , Cold Science ( 1997 ) . He has also co-authored Unstoppable Global Warming : Every 1,500 Years ( 2007 ) with Dennis Avery , and Climate Change Reconsidered ( 2009 ) with Craig Idso .   Singer has had a varied career , serving in the armed forces , government , and academia . He designed mines for the U.S. Navy during World War II , before obtaining his Ph.D. in physics from Princeton University in 1948 and working as a scientific liaison officer in the U.S. Embassy in London . He became a leading figure in early space research , was involved in the development of earth observation satellites , and in 1962 established the National Weather Bureau 's Satellite Service Center . He was the founding dean of the University of Miami School of Environmental and Planetary Sciences in 1964 , and held several government positions , including deputy assistant administrator for the Environmental Protection Agency , and chief scientist for the Department of Transportation . He held a professorship with the University of Virginia from 1971 until 1994 , and with George Mason University until 2000 .   In 1990 Singer founded the Science & Environmental Policy Project , and in 2006 was named by the Canadian Broadcasting Corporation as one of a minority of scientists said to be creating a stand-off on a consensus on climate change . Singer argues there is no evidence that global warming is attributable to human-caused increases in atmospheric carbon dioxide , and that humanity would benefit if temperatures do rise .  He is an opponent of the Kyoto Protocol , and has claimed that climate models are neither based on reality nor evidence . Singer has been accused of rejecting peer-reviewed and independently confirmed scientific evidence in his claims concerning public health and environmental issues .

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 .