(01-10-2019, 12:25 AM)Thoreauvian Wrote: Permafrost and methane hydrates
Significant thawing of the permafrost may begin at 1.5̊C of warming. Nearly a quarter of all the land in the northern hemisphere is underlaid by permafrost. When it warms, frozen organic materials from ages long past will decompose and release their carbon. IPCC climate models likely underestimate warming in this century because they don’t include permafrost releases of CO₂ and methane.
Frozen in the permafrost around the Arctic are an estimated 1.5 trillion tons of carbon, nearly twice as much carbon as in the atmosphere. Most is sequestered in the upper and vulnerable layers, two times more than what is sequestered in all of the earth’s forests. Fossil deposits of CO₂ and methane are already escaping from melting permafrost, and that melting will accelerate as global temperatures rise. By 2100, RCP 2.6 will result in a reduction of the permafrost by 37%. RCP 8.5 will result in a reduction of 81%. The permafrost could release up to an estimated 275 billion tons of carbon as CO₂ or methane.
Why don't they include permafrost? They're obviously aware of it, what would keep them from factoring it in?
