Submission by the Arctic Methane Emergency Group (AMEG) to the Environment Audit Committee’s Inquiry on Arctic Sustainability - EAC letter from AMEG
Our account of climate change and the Arctic is based on an understanding of how the Earth System operates and the essential role of the Arctic in controlling climate. Hopefully our account can bring people with hitherto different views on climate change together, unified in agreement on the action we propose to cool the Arctic and save the sea ice. This action has the potential to reverse climate change if executed with great urgency and in parallel with concerted action to reduce the levels of greenhouse gases in the atmosphere. There could be huge benefits in food production and food security, with reduced costs from weather extremes.
We reject the view that the Earth System is intrinsically stable and would return to the old norm if CO2 emissions were halted. The Arctic is a crucial component of the Earth System and the part which can change most rapidly because it contains a switch mechanism*. We have learnt that, within just a few decades, the Arctic can switch from a state where there is perennial sea ice to a state where the sea ice is seasonal, with no sea ice for part of the year. Effectively, mankind’s greenhouse gas emissions have been sufficient to operate the switch, and the switchover to seasonal ice will soon be complete. Nevertheless our group (AMEG) has studied the forces at play, and we believe that the switchover can be reversed by suitable intervention. We have two key messages for the committee: that completion of the switchover would be catastrophic and that rapid intervention is essential to prevent a complete switchover.
*The sea ice provides feedback. This feedback acts like the spring of an old-fashioned mechanical light switch. When the switch lever is operated, at first the springs act against the movement, but at a critical point (the tipping point) the springs start reinforce the movement and then the operation is completed very quickly. So it is with the Arctic. The main feedback is provided by the sea ice. As it retreats, sunshine is absorbed by the open water, heating the water to a considerable depth because of its transparency and releasing the heat to melt the sea ice from below in a positive (mutually reinforcing) feedback. But the open water also allows heat from the surface to radiate into space, which cools the water, encouraging ice to form in a negative (stabilising) feedback.
A complete rethink is required on government policy towards the Arctic and towards climate change generally. Over the past thirty years, rapid warming in the Arctic has been the main driver of climate change in the Northern Hemisphere, through a disruption of weather patterns. This disruption will get worse as warm water from the Atlantic penetrates further and further across the Arctic Ocean, melting the sea ice as it goes. Current policy for renewable energy and reducing carbon emissions comes too late to save the sea ice. To prevent dangerous climate change, the Arctic has to be refrozen such as to restore the reflective power of snow and sea ice. Recent climate change can potentially be reversed with prompt intervention on a large scale. This has to be a priority for the international community. We recommend that the UK government takes a lead in initiating and coordinating the international response as a matter of policy.
The rapid warming and melting in the Arctic has other adverse repercussions: on sea level rise as the Greenland Ice Sheet melts; on methane as permafrost thaws; and on global warming as the extra heat absorbed by the Arctic contributes to global warming. These repercussions add urgency for cooling the Arctic but also for reducing greenhouse gases in the atmosphere.