Last seven years warmest on record, sea-level rise highest in 2021: WMO report

During COP26, the WMO will launch the Water and Climate Coalition to coordinate water and climate action, and the Systematic Observations Financing Facility to improve weather observations and forecasts which are vital to climate change adaptation.

“The provisional WMO ‘State of the Global Climate 2021’ 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 the planet. Scientists are clear on the facts. Now leaders need to be just as clear in their actions,” said United Nations Secretary-General António Guterres.

WMO Secretary-General Professor Petteri Taalas said, “For the first time on record, it rained—rather than snowed—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°C in a village in British Columbia. California’s Death Valley recorded a temperature of 54.4 °C during one of the multiple heatwaves in the southwestern USA, whilst many parts of the Mediterranean experienced record temperatures. The exceptional heat was often accompanied by devastating fires.”

According to the WMO report, greenhouse gas concentrations reached new highs in 2020. Levels of carbon dioxide were 413.2 parts per million, methane at 1889 parts per billion (ppb) and nitrous oxide at 333.2 ppb. These levels respectively were 149 per cent, 262 per cent and 123 per cent more than pre-industrial levels. The increase has continued in 2021.

The global mean temperature for 2021 (based on data from January to September) was about 1.09°C above the average during the 1850-1900 period. Moreover, 2016 was the warmest year on record according to most of the datasets surveyed.

The report stated that 90% of the accumulated heat in the Earth system is stored in the ocean, which is measured through ocean heat content. “The upper 2,000 meters depth of the ocean continued to warm in 2019 reaching a new record high,” says the report, adding that most of the oceans experienced at least one strong marine heatwave in 2021.

“The ocean absorbs around 23% of the annual emissions of anthropogenic CO₂ to the atmosphere and so is becoming more acidic. Open ocean surface pH has declined globally over the last 40 years and is now the lowest it has been for at least 26,000 years. Current rates of pH change are unprecedented since at least that time. As the pH of the ocean decreases, its capacity to absorb CO₂ from the atmosphere also declines,” the report stated.

WMO has also said that the global mean sea-level rise was 2.1 mm per year between 1993 and 2002, but it jumped to 4.4 mm per year between 2013 and 2021, mostly due to the accelerated loss of ice mass from glaciers and ice sheets. The Arctic-wide sea-ice extent was at a record low in the first half of July, 2021.

The report has also stated that mass loss from North American glaciers accelerated over the last two decades, nearly doubling for the period 2015-2019 as compared to 2000-2004. Referring to the exceptional heatwaves and wildfires in North America as well as floods in western Europe, the report stated, “…it was found that the heavy rainfall had been made more likely by climate change.”

“Extreme weather during the 2020/2021 La Niña altered rainfall seasons contributing to disruptions to livelihoods and agricultural campaigns across the world. Extreme weather events during the 2021 rainfall season have compounded existing shocks. Consecutive droughts across large parts of Africa, Asia, and Latin America have coincided with severe storms, cyclones and hurricanes, significantly affecting livelihoods and the ability to recover from recurrent weather shocks,” the report stated.

It added, “Extreme weather events and conditions, often exacerbated by climate change, have had major and diverse impacts on population displacement and on the vulnerability of people already displaced throughout the year. From Afghanistan to Central America, droughts, flooding and other extreme weather events are hitting those least equipped to recover and adapt.”