There are a number of tipping points in the Arctic which threaten to rapidly escalate the threat of climate change for the whole planet. These should serve as a wake-up call in the fight against climate change.
In this episode of Climate Radio Phil England speaks to Professor Peter Wadhams, Head of the Polar Ocean Physics Group at Cambridge University and Professor Timothy Lenton, the award-winning Chair in Climate Change and Earth Systems Science at University of Exeter.
Listen to the podcast here.
The podcast explores the science behind Arctic tipping points including:
Arctic Sea Ice: New data from the CryoSat 2 satellite confirms that Arctic sea ice is declining faster than most climate models predicted. Is the trend in volume decline turning exponential or are recent observations just anomalies waiting to be explained?
Greenland Ice Sheet: Work published in 2012 indicates we are now within the estimated range for tipping the Greenland ice sheet into irreversible meltdown – although a 2008 assessment suggested this process itself could take hundreds of years to complete.
Atlantic Thermohaline Circulation: Recent observations appear to suggest that freshwater from Greenland ice melt may be weakening the Atlantic thermohaline circulation – the ocean current which includes the Gulf Stream and brings warm water to the Arctic (EAC, p.20).
Arctic Methane: There are several potential sources of methane in the arctic: on-shore permafrost (which turns into wetland as it melts); subsea permafrost on coastal shelves; and methane hydrates which are locked up on the deep ocean floor.
New evidence is emerging of the possible link between Arctic warming and extreme weather in the mid Northern latitudes such the heat waves, drought, flooding and cold spells.
According to the Arctic Council, the effects on marine animals and birds of a warming Arctic are likely to be ‘profound’. This two-part Climate Radio special from 2009 explores how Arctic First Nations peoples are finding their traditional lifestyles increasingly difficult to follow, and have been at the forefront in the struggle to stop oil and gas development in their territories, winning many important victories.
But what is the answer? If we are already at a level of average global warming that is dangerous, and the concentration of greenhouse gases in the atmosphere commits us to a further 0.5C or more – even if we stopped burning fossil fuels tomorrow – is it time to consider geoengineering?
Two days after this programme was originally broadcast, Professor Wadhams and the Arctic Methane Emergency Group submitted further written evidence to the EAC urging the government to ‘adopt a precautionary approach.’
Lenton is unconvinced that geo-engineering is an appropriate solution at this point, instead he is arguing for removal of CO2 from the atmosphere by planting trees or by chemical means, and for taking action on reducing soot pollution (also known as black carbon).
Listen to the podcast here.
This post is adapted from a more in-depth summary of this episode which can be read at the Climate Radio website.
This show is dedicated to the late Professor Seymour Laxon who died tragically on New Year’s Eve 2012. Our thoughts are with his family and friends.