Query: Consequently, CO2 levels at around 1,000 to 2,300 ppm were actually low enough to promote glaciation in the southern continent of Gondwana.

Relevant passages:
Gondwana <=SEP=> In paleogeography , Gondwana ( -LSB- pronɡɒndˈwɑːnə -RSB- ) , also Gondwanaland , is the name given to an ancient supercontinent . It is believed to have sutured about , joining East Gondwana to West Gondwana . Gondwana formed prior to Pangaea , and later became part of it .   Around , Gondwana and Laurasia joined together to form the supercontinent Pangaea , which existed until approximately . Gondwana then separated from Laurasia ( the mid-Mesozoic era ) in the breakup of Pangaea , drifting farther south after the split . Gondwana itself then also broke apart .   Gondwana included most of the landmasses in today 's Southern Hemisphere , including Antarctica , South America , Africa , Madagascar , and the Australian continent , as well as the Arabian Peninsula and the Indian subcontinent , which have now moved entirely into the Northern Hemisphere .   The continent of Gondwana was named by Austrian scientist Eduard Suess , after the Gondwana region of central northern India which is derived from Sanskrit for `` forest of the Gonds '' . The name had been previously used in a geological context , first by H.B. Medlicott in 1872 , from which the Gondwana sedimentary sequences ( Permian-Triassic ) are also described .   The adjective `` Gondwanan '' is in common use in biogeography when referring to patterns of distribution of living organisms , typically when the organisms are restricted to two or more of the now-discontinuous regions that were once part of Gondwana , including the Antarctic flora . For example , the plant family Proteaceae , known only from southern South America , South Africa , Australia , and New Zealand , is considered to have a `` Gondwanan distribution '' . This pattern is often considered to indicate an archaic , or relict , lineage .

Supercontinent <=SEP=> In geology , a supercontinent is the assembly of most or all of Earth 's continental blocks or cratons to form a single large landmass . However , the definition of a supercontinent can be ambiguous . Many earth scientists use the term `` supercontinent '' to mean `` a clustering of nearly all continents '' . This definition leaves room for interpretation when labeling a continental body and is easier to apply to Precambrian times . Using the first definition provided here , Gondwana is not considered a supercontinent , because the landmasses of Baltica , Laurentia and Siberia also existed at the same time but physically separate from each other . The landmass of Pangaea is the collective name describing all of these continental masses when they were most recently in proximity to one another . This would classify Pangaea as a supercontinent . According to the modern definitions , a supercontinent does not exist today . Supercontinents have assembled and dispersed multiple times in the geologic past ( see table ) . The positions of continents have been accurately determined back to the early Jurassic . However , beyond , continental positions are much less certain .

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 .

Carbon dioxide in Earth's atmosphere <=SEP=> Carbon dioxide is an important trace gas in Earth 's atmosphere . Currently it constitutes about 0.041 % ( equal to 410 parts per million ; ppm ) by volume of the atmosphere . Despite its relatively small concentration is a potent greenhouse gas and plays a vital role in regulating Earth 's surface temperature through radiative forcing and the greenhouse effect . Reconstructions show that concentrations of in the atmosphere have varied , ranging from as high as 7,000 ppm during the Cambrian period about 500 million years ago to as low as 180 ppm during the Quaternary glaciation of the last two million years .   Carbon dioxide is an integral part of the carbon cycle , a biogeochemical cycle in which carbon is exchanged between the Earth 's oceans , soil , rocks and the biosphere . Plants and other photoautotrophs use solar energy to produce carbohydrate from atmospheric carbon dioxide and water by photosynthesis . Almost all other organisms depend on carbohydrate derived from photosynthesis as their primary source of energy and carbon compounds .   The current episode of global warming is attributed to increasing emissions of and other greenhouse gases into Earth 's atmosphere . The global annual mean concentration of in the atmosphere has increased by more than 40 % since the start of the Industrial Revolution , from 280 ppm , the level it had for the last 10,000 years leading up to the mid-18th century , to 399 ppm as of 2015 . The present concentration is the highest in at least the past 800,000 years and likely the highest in the past 20 million years . The increase has been caused by anthropogenic sources , particularly the burning of fossil fuels and deforestation . The daily average concentration of atmospheric CO2 at Mauna Loa Observatory first exceeded 400 ppm on 10 May 2013 . It is currently rising at a rate of approximately 2 ppm/year and accelerating . An estimated 30 -- 40 % of the released by humans into the atmosphere dissolves into oceans , rivers and lakes , which contributes to ocean acidification .