The World Meteorological Organisation (WMO) has said in the preliminary findings of its annual State of the Global Climate report that the last decade has been one of high heat around the world, meaning it will almost certainly become the hottest on record.
The report found that global temperatures for 2010 to 2019 were about 1.1C above the pre-Industrial average. Meanwhile, 2019 looks set to be the second or third warmest year on record, with 2016 holding the record, with its exceptionally strong El Nino event.
Concentrations of atmospheric CO2 reached a record high of 407.8 parts per million in 2018 and continued to rise in 2019. Sea level rises are accelerating, because of melting ice sheets in Greenland and Antarctica. Ice loss for the Greenland Ice Sheet from September 2018 to August 2019 has been calculated at 329 Gigatonnes (Gt). From 2002 to 2016, Greenland lost about 260Gt of ice per year, with 458Gt lost in 2011-12.
The daily Arctic sea ice extent minimum was the second lowest in the satellite record in September 2019, whilst Antarctica has seen record low ice extents in several months of 2019.
Sea water is now more than a quarter more acidic than it was before the Industrial period, degrading vital marine ecosystems. More than 90% of the excess energy accumulating in the atmosphere as a result of greenhouse gas emissions goes into the oceans. Ocean heat content in the upper 700m (with data stretching back to the 1950s) and the upper 200m (data from 2005 onwards) have shown record or near-record levels throughout 2019, with average temperatures for the year so far exceeding the new record set in 2018.
“On a day-to-day basis, the impacts of climate change play out through extreme and “abnormal” weather. And, once again in 2019, weather and climate related risks hit hard. Heatwaves and floods which used to be “once in a century” events are becoming more regular occurrences. Countries ranging from the Bahamas to Japan to Mozambique suffered the effect of devastating tropical cyclones. Wildfires swept through the Arctic and Australia,” said WMO Secretary-General Petteri Taalas.
Evidence for this is clear. For example, in the 12 months from July 2018 to June 2019, the contiguous United States saw their highest average annual rainfall ever, at 962mm.
Two major heatwaves occurred in Europe in late June and late July, with France setting a new record high temperature of 46C, a massive 1.9C above the previous record. National records were also set in Germany (42.6C), the Netherlands (40.7C), Belgium (41.8C), Luxembourg (40.8C) and here in the UK (38.7C). Helsinki in Finland also saw its highest temperature on record (33.2C) on 28 July. Meanwhile, Australia's mean summer temperature was almost 1C higher than the previous record.
Extreme heat conditions are taking an increasing toll on human health and health systems with greater impacts where there are ageing populations, urbanization, urban heat island effects, and health inequities. In 2018, a record 220 million more heatwave exposures by vulnerable persons over the age of 65 occurred, compared with the average for the baseline of 1986-2005.
“If we do not take urgent climate action now, then we are heading for a temperature increase of more than 3°C by the end of the century, with ever more harmful impacts on human wellbeing,” said Mr Taalas. “We are nowhere near on track to meet the Paris Agreement target.”