1,700 billion metric tonnes of carbon dioxide. That's twice the
current record amount of atmospheric CO2. 1,700 billion metric
tonnes is the estimated amount of CO2 held in the northern
hemisphere's permafrost that is now at risk of being released. A
report of the U.N. Environment Programme released at the Doha
climate summit warns that data from existing monitoring
networks, "indicates that large-scale thawing of permafrost may
have already started." With Arctic temperatures warming twice as
fast as the global average, scientists estimate thawing
permafrost could release large amounts of carbon into the
atmosphere through the end of the century with significant
climate impacts. Thawing permafrost could emit 43 billion to 135
billion metric tons of carbon dioxide equivalent by 2100, and
246 billion to 415 billion metric tons of CO2 by 2200, the U.N.
report says. "Uncertainties are large, but emissions from
thawing permafrost could start within the next few decades and
continue for several centuries, influenci