Transcript Could thawing permafrost accelerate global warming?

Could Thawing Permafrost Accelerate
Global Warming?
by Dr. Aaron Thierry
The School of Geosciences, The University of Edinburgh, U.K.
Email: [email protected]
Source: International Permafrost Association
What is Permafrost?
Permafrost is soil that has been frozen for at least two
consecutive years.
It is found in large parts of the Arctic & in the Himalayas –
encompassing about 25% of the northern hemisphere land area.
There’s more than twice as much carbon stored in permafrost as
there is in the whole atmosphere.
Did you know that scientists have found Mammoths frozen in
permafrost? This shows that much of it has been frozen since the
last ice age – thousands of years ago!
Find out more: http://tinyurl.com/lu27dkt
Source: Alex Petrov
Permafrost and Climate Change
Global warming, due to man-made greenhouse gas
emissions from burning fossil fuels, is happening faster in
the Arctic than anywhere else. This warming is causing
permafrost to begin to thaw.
The graph opposite is from a scientific report by the
Intergovernmental Panel on Climate Change – it shows the
projected decline in the area of surface permafrost.
Source: IPCC (2013) Fig 12.30
The different coloured lines represent different scenarios.
Dark blue represents a scenario in which we take action to
dramatically reduce our carbon emissions. The red one is
one in which we keep burning more & more fossil fuels, if
that happens then by 2100 the surface permafrost might be
nearly all gone!
Find out more: http://tinyurl.com/co73ndb
Why is Permafrost important?
When permafrost thaws, bacteria can start to breakdown the
soil – like when a freezer breaks & all the food goes off.
As microbes breakdown soil, Carbon Dioxide (CO2) & other
heat trapping greenhouse gases are released. This could
possibly create a vicious cycle whereby warming causes thaw
& thaw then causes more warming!
On the other hand Arctic plants also grow better in warmer
climates & take up more CO2 - this might offset some of the
soil decomposition.
My work at the University of Edinburgh on the CYCLOPS
project is trying to better understand the balance between
plant sinks & soil sources of carbon in the Arctic.
Source: National Science Foundation
To find out more go to:
http://arp.arctic.ac.uk/projects/carbon-cycling-linkages-permafrost-systems-cyclops/