Record atmospheric greenhouse gas concentrations and associated accumulated heat “have propelled the planet into uncharted territory, with far-reaching repercussions for current and future generations”, the World Meteorological Organisation (WMO) warned on Sunday.
The past seven years are on track to be the seven warmest on record, according to the provisional WMO State of the Global Climate 2021 report. The report will inform Cop26 negotiations over the next fortnight.
Data for the first nine months of the year, on which the report is based, shows a temporary cooling “La Niña” event means 2021 is expected to be “only” the fifth to seventh warmest year on record. “But this does not negate or reverse the long-term trend of rising temperatures,” the report states. Global sea level rise accelerated since 2013 to a new high in 2021, with continued ocean warming and ocean acidification.
The report combines input from United Nations agencies, national meteorological and hydrological services and scientists. It highlights impacts on food security, population displacement and crucial ecosystems that are undermining progress towards the UN sustainable development goals.
“The report draws from the latest scientific evidence to show how our planet is changing before our eyes. From the ocean depths to mountain tops, from melting glaciers to relentless extreme weather events, ecosystems and communities around the globe are being devastated. Cop26 must be a turning point for people and planet,” said UN secretary-general António Guterres.
“Scientists are clear on the facts. Now leaders need to be just as clear in their actions. The door is open; the solutions are there. Cop26 must be a turning point. We must act now – with ambition and solidarity – to safeguard our future and save humanity,” Mr Guterres said.
Warming impacts
WMO secretary general Prof Petteri Taalas summed up the unprecedented warming effects on the planet: "It rained – rather than snowed – for the first time on record at the peak of the Greenland ice sheet. Canadian glaciers suffered rapid melting. A heatwave in Canada and adjacent parts of the USA pushed temperatures to nearly 50 degrees in a village in British Columbia.
"Death Valley, California, reached 54.4 degrees during one of multiple heatwaves whilst many parts of the Mediterranean experienced record temperatures. Exceptional heat was often accompanied by devastating fires."
Months' worth of rainfall fell in the space of hours in China and parts of Europe saw severe flooding, leading to dozens of casualties and billions in economic losses. "A second successive year of drought in sub-tropical South America reduced the flow of mighty river basins and hit agriculture, transport and energy production," Prof Taalas added. "Extreme events are the new norm. There is mounting scientific evidence that some of these bear the footprint of human-induced climate change."
At the current rate of emissions’ increase we will see a temperature rise by the end of this century far in excess of the Paris Agreement targets of 1.5 to 2 degrees above pre-industrial levels, he said. “Cop26 is a make-or-break opportunity to put us back on track.”
The provisional report provides a snapshot of climate indicators such as greenhouse gas concentrations, temperatures, extreme weather, sea level, ocean warming and ocean acidification, glacier retreat and ice melt, as well as socio-economic impacts. It is one of the flagship scientific reports that will inform negotiations by almost 200 states in the coming days.
Reacting to the WMO data, Prof Hannah Cloke of the University of Reading said: "As a scientist primarily studying floods and heatwaves, I believe 2021 should stand out as something of an annus horribilis. Devastating floods in Europe, China and South America, and killer heatwaves and fires in North America and southern Europe, for example, ought to serve as a canary in the coal mine to spur faster action to adapt society to the reality of a changing climate."
She added: “We should remember this canary also represents thousands of unnecessary deaths and billions of dollars’ worth of destruction.”
PANEL;
Emissions
In 2020, greenhouse gas concentrations reached new highs. CO2 levels were at 413 parts per million (ppm); methane at 1,889 parts per billion (ppb) and nitrous oxide at 333 ppb – up 149 per cent, 262 per cent and 123 per cent respectively on pre-industrial (1750) levels. The increase continued in 2021.
Temperatures
Global mean temperature for January to September 2021 was 1.09 degrees above the 1850-1900 average.
Oceans
About 90 per cent of the accumulated heat in “the Earth system” is stored in the ocean. The upper 2,000 metre depth continued to warm in 2019 reaching a record high. Preliminary analysis suggests 2020 exceeded that. All data sets agree ocean warming rates show a particularly strong increase in the past two decades and oceans will continue to warm in the future – it will take hundreds of years to reduce this warming.
