2013 was the seventh warmest year on record and saw one of the strongest cyclones, some of the longest heatwaves and the most topsy-turvy weather experienced in decades.
Nowhere is thought to have witnessed faster change than Nikkaluokta, a small Lapland village above the Arctic circle in northern Sweden. On 3 December, it was enjoying an unseasonally warm 4.7C. Within a few days, the temperature had dropped to a bone-chilling -40.8C (-41.4F) but on 10 December it rose again in just a few hours to a balmy 7.7C. The 48.5C rise in under 48 hours is one of the greatest ever recorded and is comparable to the world’s fastest-temperature rise: 27C in just two minutes in Spearfish, South Dakota back in 1943.
What happened in Lapland was, on the surface at least, not unusual, abrupt short-term weather change possibly caused by a convoluted jet stream. But in a major report this month, the US National Research Council warned that abrupt climate change was already being seen with the collapse of the Arctic sea ice and in extinction rates. The good news, it said, was that most of the extreme climate predictions made over the past decade, such as an upwelling of methane from the bottom of the oceans or a shutdown of the Atlantic conveyor, were extremely unlikely – at least in the medium term. But the message was clear: if temperatures go on rising, expect the unexpected over the next 100 years.
The IPCC 5th assessment report, which is considered the consensus of world scientists, was unequivocal that climate change was happening fast. In September, it stated that each of the last three decades had been successively warmer at the Earth’s surface than at any preceding decade since measurements started in 1850. The period 1983-2012 was probably the warmest in the past 1,400 years, it said, and both the Greenland and Antarctic ice sheets were losing mass, along with most glaciers worldwide.
The Arctic in 2013 saw nowhere near as much sea ice loss as the exceptional 2012 when all records were broken by nearly 20%, but the relatively cool year still witnessed the sixth greatest ice loss since observations began in 1979. All seven lowest minimum ice extents have now occurred in the past seven years. Significantly for sea level rise, IPCC scientists said the loss of ice from Greenland’s ice sheet, which is situtated on land, has probably increased from around 34bn tonnes a year in the last decade of the 20th century to 215bn tonnes a year today.