On Wednesday, the Greenland ice sheet lost so much water that it could have filled four million Olympic swimming pools. Ten gigatons of ice. Gone. In 24 hours.
Summer melting has always taken place. And, during naturally occurring heatwaves, the flow of meltwater can be pronounced. But extreme heatwaves are now taking place at least ten times more frequently than 100 years ago, according to the World Meteorological Organization (WMO). And we all – or at least those of us not taken in by fanciful conspiracy theories and the unscientific pontifications – know the reason why: the continuing rise in levels of greenhouse gases caused mostly by burning fossil fuels.
The warning signs in the Arctic are much more obvious than in other parts of the planet. Scientists believe the North Pole could be completely free of summer sea ice – possibly for the first time in 100,000 years – within the next few decades.
Melting sea ice does not contribute to sea-level rise, but the loss of reflective white ice means the darker sea will absorb more energy from the sun, causing further warming in a feedback loop, one of many that it is feared could eventually lead to a hugely dangerous process known as “runaway global warming”.
As Greenland’s ice melts, its land is burning. This summer has seen the island become part of a new ‘ring of fire’ with Alaska and Siberia. There have been more than 100 major wildfires in the Arctic Circle since the beginning of June. The WMO described the number of blazes as “unprecedented”.
Those who claim climate science is a massive hoax, who don’t trust scientists to read a thermometer, have a problem. Natural ‘thermometers’ – like ice sheets and glaciers that get smaller as the world gets warmer – have been giving a crystal clear signal about what has been going on for years. The idea that carbon dioxide is a greenhouse gas was established in the mid-19th century, a discovery that led one scientist to predict in the 1890s that the world would start to get warmer if we continued to use fossil fuels.
The dramatic loss of ice in Greenland is a warning. It shows what just one degree of average global warming can do. If we carry on burning fossil fuels, these effects are only going to get worse, but we are gradually realising the need to stop. Given the importance of North Sea oil to Scotland’s economy, it is vital to prepare and find a way to manage this change successfully.