What would happen if the Arctic sea ice kept falling to, say, under 11 million square km by end April and then followed a trajectory similar to 2012 for the next four months? As the animation below shows, such a scenario could wipe out all Arctic sea ice for more than a month from September 1st, 2015.
|Sea ice thickness image, Naval Reserach Laboratory|
So, what would happen if the sea ice was wiped out like that?
Sunlight that previously went into melting the sea ice, as well as sunlight that was previously reflected back into space by sea ice, would be absorbed by the Arctic Ocean instead. In other words, we can expect massive warming. In an earlier post, Prof. Peter Wadhams warned that warming due to Arctic snow and ice loss may well exceed 2 W per square m, i.e. it could more than double the net warming causing by all emissions by all people of the world.
|Professor Peter Wadhams on albedo changes in the Arctic|
As a result, electricity supply could stutter, and much industrial activity may stop, while there may be lots of traffic problems, etc. This is only one of the problems, though, as discussed in the 2007 post Ten Dangers of Global Warming. Food supply will come under threat due to crop loss and reduced supply of food to shops, made worse by traffic problems. As discussed back in 2011, much of the soot from firestorms in Siberia could settle on the ice in the Himalaya Tibetan plateau, melting the glaciers there and causing short-term flooding followed by rapid decrease of the flow of ten of Asia’s largest river systems that originate there, with more than a billion people’s livelihoods depending on the continued flow of this water.
Less industrial activity will not cause an immediate fall of tenmperatures, though. Instead, it would make that the aerosols that are currently sent up in the air by such activities and that are currently masking the full wrath of global warming, will fall out of the air in a matter of weeks. Until now, about half of the global temperature rise is suppressed by such aerosols. Stopping aerosols release overnight could make temperatures rise abruptly by 1.2°C (2.16°F) in a matter of weeks.
Methane eruptions from the seafloor of the Arctic Ocean typically start becoming huge around the end of October.
|Conclusion from a paper presented at the 2008 EGU conference, on background|
of a frame from a video interview by Nick Breeze with Natalia Shakhova.
Further warming of the Arctic Ocean could cause methane to erupt from the seafloor of the Arctic Ocean in quantities that could quickly double and tripple the amount of methane in the atmosphere.
The combined impact of such feedbacks could wipe out crops, deplete water supplies and make a huge number of species go extinct very quickly, including human beings.
In conclusion, the situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog.