By Tim Radford | 23 April 2021
Climate News Network
The year of plague and fire, record heat, melting ice and rising seas: who’s surprised 2021 is UN’s “year for action”?
The world’s most authoritative global forecasters have soberly confirmed conclusions first outlined in January. The year 2020, the year of Covid-19, of planet-wide economic slowdown, did almost nothing to damp global heating, which is why the UN says 2021 must be a “year of action”.
Even at a point in the natural weather cycle in which tropical conditions should have been cooler, it was hotter: one of the three warmest years on record.
The decade 2011-2020 is now the hottest on record. Global average temperatures reached 1.2°C above the long-term average for most of human history.
Carbon dioxide concentrations in the atmosphere – for most of human history around 285 parts per million – have now reached 410 ppm. This year they could reach 414 ppm, thanks to ever-greater use of fossil fuels.
Six years after the nations of the world vowed, in Paris in 2015, to act to keep global temperature rise “well below” 2°C, and ideally at 1.5°C, the last six years have all been the warmest since records began.
All this is catalogued in the World Meteorological Organisation (WMO) report State of the Global Climate 2020. It is the 28th such report since 1993. It simply confirms and underscores provisional conclusions published in January.
Earth is now committed to a 2°C hotter future https://t.co/0l6BLQWCWt
Earthlings are on our way to the global climate we promised barely six years ago we’d never reach − a 2°C hotter future
“Our results suggest we have most likely already emitted enough carbon to exceed 2°C” pic.twitter.com/LvQffDTr3h
— Svein T veitdal (@tveitdal) January 12, 2021
“The basic message remains the same, and we now have 28 more years of data that show significant temperature increases over land and sea as well as other changes like sea level rise, melting of sea ice and glaciers, and changes in precipitation patterns,” said Petteri Taalas, WMO secretary-general.
“All key climate indicators and associated impact information in this report highlight relentless, continuing climate change, an increasing occurrence and intensification of extreme events, and severe losses and damage, affecting people, societies and economies.”
The report appeared as US President Biden convened a virtual summit on climate. It showed, said UN secretary-general António Guterres, that there is no time to waste: “The climate is changing and the impacts are already too costly for people and the planet. This is the year for action.”
In the 2020 summer, the Arctic sea ice dwindled, for only the second time in recorded history, to below below 4 million square kilometres. The Greenland ice sheet lost 152 billion tonnes of ice between September 2019 and August 2020. The Antarctic ice sheet has been losing between 175 and 225 billion tonnes of ice a year in meltwater.
Because such loses are difficult to imagine, the report helpfully points out that 200 billion tonnes is about twice the annual discharge of the river Rhine into the North Sea.
It was a year of record temperatures: the mercury reached 38°C in the town of Verkhoyansk in the Siberian Arctic. Death Valley in California recorded an all-time global record of 54.4°C. Cuba, Dominica, Grenada and Puerto Rico all experienced record national temperatures. In a suburb of Australia’s city Sydney, the thermometer tipped 48.9°C.
Same but worse
Heavy rain and floods in the Sahel and the Horn of Africa triggered destructive swarms of the desert locust. An estimated 690 million people – 9% of humankind – were undernourished. The US saw its largest wildfires ever. Until 2020, the record number of hurricanes to hit the US coasts had stood at nine. Last year there were 12: one of these, Hurricane Laura, caused $19bn in losses.
A “gigafire,” a terrible new word we must now contend with, is a blaze spanning 1 million acres. That’s larger than the entire state of Rhode Island. https://t.co/a9EAozEs0J
— Climate Reality (@ClimateReality) October 24, 2020
Scientists have greeted the report with weary resignation and impatience. “Here we go again: 28 issues since the annual exercise began, the message is the same, yet incrementally worse. More floods, fires, heatwaves, storms, melting ice, and natural and human impacts,” said Chris Rapley, a climate scientist at University College London.
“Especially worrisome is that, despite the societal impact of Covid, the signals – atmospheric greenhouse concentrations, ocean heat content, decadal temperature – continued to rise, in some cases with clear acceleration. With estimates of the global mean temperature rise since pre-industrial times now in the range 1.15-1.28°C, the 1.5°C Paris guard-rail is close to being breached.
“The bottom line? The way we have organised and are running human affairs is destabilising the climate system, with predictable and increasingly dire consequences.”
Tim Radford, a founding editor of Climate News Network, worked for The Guardian for 32 years, for most of that time as science editor. He has been covering climate change since 1988.
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