photo: Dave Bezaire & Suzi Havens-Bezaire via flickr
There's no doubt that Arctic permafrost stores a huge amount of greenhouse gases and as the planet warms and the permafrost thaws the climate change impact could be huge. Well, according to a new study in Global Biogeochemical Cycles (via Reuters) we may be seriously underestimating the impact. In fact the amount of carbon stored in permafrost is double previous estimates:Researcher Pep Canadell of the Global Carbon Project on this data:
Projections show that almost all near-surface permafrost will disappear by the end of this century exposing large carbon stores to decomposition and release of greenhouse gases.
Overall, Canadell said that if only 10% of the permafrost melts it would release enough carbon into the atmosphere to add a further 0.7°C of warming onto whatever warming is caused directly by human activity. This is equivalent to all the warming that has already taken place since the beginning of the industrial age.
Furthermore, Canadell's computer models show that global warming could easily push permafrost melt passed a tipping point where future melting was irreversible. Remember that the 0.7°C additional is only from 10% melting, imagine what could happen if all of it melts?
NOTE: This publication appears to be a reiteration of research first published nine months ago. The significant thing to take away is that if just small part of the permafrost melts it could make holding global temperature rise below the critical 2°C threshold very difficult.
Melting Permafrost Greenhouse Gas Emission Held at Bay by New Plant Growth, For a Little While
60% More Greenhouse Gases Trapped in Permafrost Than Previously Thought
Melting Arctic Ice Increases Permafrost Thaw Farther Inland Than Previously Thought