A popular scare story running in the media is that the Greenland ice sheet is about to slip its moorings under ferocious and unprecedented Arctic heat and arrive in the reader’s front room any day now (I exaggerate, but not much). Meanwhile back in the scientific world, scientists are scrambling to understand what natural causes lie behind the sudden slow-down in Greenland’s summer warming and ice loss dating back to 2010. The recovery of Arctic summer sea ice has been spectacular of late, with the U.S.-based National Snow and Ice Data Center reporting that this year’s September minimum was 1.28 million square kilometres higher than the 2012 low point of 3.39 million square kilometres.
Three Japanese climatologists have recently published a paper noting that “frequent occurrence of central Pacific El Niño events has played a key role in the [abrupt] slow-down of Greenland warming and possibly Arctic sea ice loss”. Of course such findings play havoc with the simplistic ‘settled’ science notion that carbon dioxide produced by humans burning fossil fuel is the main, if not only, driver of global temperature warming or cooling – a notion that leads many green activists to claim that the climate will stop changing if society signs on to a ‘Net Zero’ CO2 emissions agenda.
For instance, a bizarre ‘fact check’ on a recently published Daily Sceptic article by Facebook partner Climate Feedback claimed there had been no natural climate change for almost 200 years. It quoted Professor Timothy Osborn of the University of East Anglia, who said: “The warming from the late 1800s to the present is all due to human-caused climate change, because natural factors have changed little since then, and even would have caused a slight cooling over the last 70 years rather than the warming we have observed.”
The Japanese scientists argue that they have been able to show that El Niño natural weather oscillations have driven “atmospheric teleconnection” and shifted the tropical rainfall zone to the north. The higher warming up to 2012 was “accelerated” by heat from the Pacific and a phase in the North Atlantic sea current oscillation that favoured warmer conditions over Greenland and enhanced ice melt. Changes around Greenland can be attributed to “natural variability, rather than anthropogenic forcing”, note the scientists, “although most climate models were unable to reasonably simulate the unforced natural variability over Greenland”.