<P> Carbon exists in various forms in the atmosphere . Carbon dioxide and methane (CH) are partly responsible for the greenhouse effect and among the most important human - contributed greenhouse gases . </P> <P> In the past two centuries, human activities have altered the global carbon cycle, most significantly in the atmosphere . Although carbon dioxide levels have changed naturally over the past several thousand years, human emissions of carbon dioxide into the atmosphere have created unnatural fluctuations . Changes in the amount of atmospheric CO are considerably altering weather patterns and indirectly influencing oceanic chemistry . Current carbon dioxide levels in the atmosphere exceed measurements from the last 1,000 years and levels are rising quickly, making it of critical importance to better understand how the carbon cycle works and what its effects are on the global climate . </P> <Table> Carbon pools in the major reservoirs on earth . <Tr> <Th> Pool </Th> <Th> Quantity (gigatons) </Th> </Tr> <Tr> <Td> Atmosphere </Td> <Td> 720 </Td> </Tr> <Tr> <Td> Oceans (total) </Td> <Td> 38,400 </Td> </Tr> <Tr> <Td> Total inorganic </Td> <Td> 37,400 </Td> </Tr> <Tr> <Td> Total organic </Td> <Td> 1,000 </Td> </Tr> <Tr> <Td> Surface layer </Td> <Td> 670 </Td> </Tr> <Tr> <Td> Deep layer </Td> <Td> 36,730 </Td> </Tr> <Tr> <Td> Lithosphere </Td> <Td> </Td> </Tr> <Tr> <Td> Sedimentary carbonates </Td> <Td>> 60,000,000 </Td> </Tr> <Tr> <Td> Kerogens </Td> <Td> 15,000,000 </Td> </Tr> <Tr> <Td> Terrestrial biosphere (total) </Td> <Td> 2,000 </Td> </Tr> <Tr> <Td> Living biomass </Td> <Td> 600 - 1,000 </Td> </Tr> <Tr> <Td> Dead biomass </Td> <Td> 1,200 </Td> </Tr> <Tr> <Td> Aquatic biosphere </Td> <Td> 1 - 2 </Td> </Tr> <Tr> <Td> Fossil fuels (total) </Td> <Td> 4,130 </Td> </Tr> <Tr> <Td> Coal </Td> <Td> 3,510 </Td> </Tr> <Tr> <Td> Oil </Td> <Td> 230 </Td> </Tr> <Tr> <Td> Gas </Td> <Td> 140 </Td> </Tr> <Tr> <Td> Other (peat) </Td> <Td> 250 </Td> </Tr> </Table> <Tr> <Th> Pool </Th> <Th> Quantity (gigatons) </Th> </Tr>

Where is carbon stored in the largest amounts on earth
find me the text answering this question