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THE EVER-CHANGING IPCC CARBON CYCLE |
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11 October 2011: An article recently published in the journal Nature casts doubt on the IPCC's Carbon Cycle Model. Researchers at the Scripps Institute of Oceanograpy find that previous estimates of the amount of carbon dioxide absorbed annually by global vegetation may be low by as much as 45%.
A cornerstone of the theory of man-made global warming is the concept that emissions of CO2 and other greenhouse gases are accumulating in the atmosphere. In its 2007 Fourth Assessment Report, the IPCC states:
"The additional burden of CO2 added to the atmosphere by human activities ... leads to the current 'perturbed' global carbon cycle ... these perturbations to the natural carbon cycle are the dominant driver of climate change because of their persistent effect on the atmosphere."
The IPCC further claims that carbon dioxide remains for a long time in the atmosphere:
"About 50% of a CO2 increase willl be removed from the atmosphere within 30 years, and a further 30% will be removed within a few centuries. The remaining 20% may stay in the atmosphere for many thousands of years."
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The IPCC bases its conclusions on the Carbon Cycle Model shown at right, which was published in the 2007 Fourth Assessment Report. The model estimates that annual emissions of carbon from the land and biomass is 122 gigatons of carbon, with an annual absorption by the land and biomass of 123 gigatons. Annual man-made emissions are estimated at 6 gigatons. The model also shows that about 215 of the 750 gigatons of carbon in the atmosphere is exchanged with the biosphere and oceans, or about 29% of the carbon in the atmosphere each year. Many skeptical scientists have questioned the IPCC Carbon Cycle Model, pointing out that the uncertainties in the carbon flows are very large--much, much larger than yearly human emissions.
The scientists at the Scripps Institute recently found that yearly uptake of global vegetation is probably in the range of 150 to 175 gigatons of carbon, or up to 45% more than in the current IPCC models. This 45% error in one of the carbon cycle flows is 8 times more than total annual human industrial emissions. Read more about it here.
The article calls into question the accuracy of the whole Carbon Cycle Model. It's clear that climate science really doesn't have a good handle on the estimates of global carbon flows.
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The Carbon Cycle According to the IPCC. Numbers in billions of tons of carbon. The numbers shown are estimated carbon totals residing in each climate subsystem. The numbers next to the arrows are estimates of annual transfers of carbon in the form of CO2. Diagram from Climatism! Science, Common Sense, and the 21st Century's Hottest Topic. |
Should these new estimates be true, we can conclude that 1) annual emissions by mankind are a yet smaller part of Earth's carbon cycle, only about 2% of the flows, and 2) about 34% of all the carbon dioxide in the atmosphere is exchanged with the biosphere and oceans each year. These findings further challenge the IPCC's assertions that mankind's relatively small emissions have "perturbed the carbon cycle" and that CO2 "remains in the atmosphere for thousands of years."
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Last Updated on Friday, 18 November 2011 05:12 |