The complete collapse of Arctic sea ice during the summer months may happen within four years, according to one of the world’s leading sea ice researchers.
The Arctic sea ice is very rapidly disappearing, much faster than climate models have predicted. It reached its lowest ever recorded extent earlier this summer, weeks before the melt season was even over.
In an email to the Guardian, Professor Peter Wadhams of Cambridge University says: “Climate change is no longer something we can aim to do something about in a few decades’ time, and that we must not only urgently reduce CO2 emissions but must urgently examine other ways of slowing global warming, such as the various geoengineering ideas that have been put forward.”
Some of those geo-engineering ideas could have unintended effects worse than climate change itself, though — they remain a heavily-debated solution. The most prominent current ideas include: reflecting the sun’s light back into space with aerosols or mirrors; turning clouds a whiter color; and seeding the ocean with minerals in order to encourage massive plankton blooms that, theoretically, could sequester more CO2.
Professor Wadhams has spent “many years collecting ice thickness data from submarines passing below the arctic ocean. He predicted the imminent break-up of sea ice in summer months in 2007, when the previous lowest extent of 4.17 million square kilometres was set. This year, it has unexpectedly plunged a further 500,000 sq km to less than 3.5m sq km.”
“I have been predicting [the collapse of sea ice in summer months] for many years. The main cause is simply global warming: as the climate has warmed there has been less ice growth during the winter and more ice melt during the summer,” Dr Wadhams said.
“At first this didn’t [get] noticed; the summer ice limits slowly shrank back, at a rate which suggested that the ice would last another 50 years or so. But in the end the summer melt overtook the winter growth such that the entire ice sheet melts or breaks up during the summer months.
“This collapse, I predicted would occur in 2015-16 at which time the summer Arctic (August to September) would become ice-free. The final collapse towards that state is now happening and will probably be complete by those dates”.
According to Wadhams, the implications of this are “terrible,” primarily because of the domino effect this will have, accelerating the arctic death spiral. “The positives are increased possibility of Arctic transport, increased access to Arctic offshore oil and gas resources. The main negative is an acceleration of global warming.”
“As the sea ice retreats in summer the ocean warms up (to 7C in 2011) and this warms the seabed too. The continental shelves of the Arctic are composed of offshore permafrost, frozen sediment left over from the last ice age. As the water warms the permafrost melts and releases huge quantities of trapped methane, a very powerful greenhouse gas so this will give a big boost to global warming.”
Image Credits: Arctic Ice Melt via Wikimedia Commons; NASA/Goddard Scientific Visualization Studio