2021 joined the list of the seven warmest years on record and the seventh consecutive year when the global temperature has been more than 1°C above pre-industrial levels.
Although average global temperatures were temporarily cooled by the 2020-2022 La Niña events, 2021 was still one of the seven warmest years on record, according to six leading international datasets consolidated by the World Meteorological Organization (WMO).
The average global temperature in 2021 was about 1.11 (+ 0.13) °C above the pre-industrial (1850-1900) levels. Global warming and other long-term climate change trends are expected to continue as a result of record levels of heat-trapping greenhouse gases in the atmosphere, the agency said.
DATASETS
The agency used six international datasets to ensure the most comprehensive, authoritative temperature assessment. The same data are used in its annual State of the Climate reports which inform the international community on global climate indicators. WMO used datasets developed and maintained by the United States National Oceanic and Atmospheric Administration (NOAA), NASA’s Goddard Institute for Space Studies (NASA GISS), the United Kingdom’s Met Office Hadley Centre and the University of East Anglia’s Climatic Research Unit (HadCRUT), and the Berkeley Earth group. WMO also uses reanalysis datasets from the European Centre for Medium Range Weather Forecasts and its Copernicus Climate Change Service, and the Japan Meteorological Agency (JMA).
The WMO noted that the rankings of individual years should be considered in the long-term context, especially since the differences between individual years are sometimes marginal. Since the 1980s, each decade has been warmer than the previous one, it said and added that this is expected to continue.
WARMEST
The warmest seven years have all been since 2015, with 2016, 2019 and 2020 constituting the top three. An exceptionally strong El Niño event occurred in 2016, which contributed to record global average warming. “Back-to-back La Niña events mean that 2021 warming was relatively less pronounced compared to recent years. Even so, 2021 was still warmer than previous years influenced by La Niña. The overall long-term warming as a result of greenhouse gas increases is now far larger than the year-to-year variability in global average temperatures caused by naturally occurring climate drivers, said WMO Secretary-General, Prof. Petteri Taalas.
“The year 2021 will be remembered for a record-shattering temperature of nearly 50°C in Canada, comparable to the values reported in the hot Saharan Desert of Algeria, exceptional rainfall, and deadly flooding in Asia and Europe as well as drought in parts of Africa and South America. Climate change impacts and weather-related hazards had life-changing and devastating impacts on communities on every single continent,” Prof. Taalas said.
UNDENIABLE TREND
WMO chief Taalas said; “The overall long-term warming as a result of greenhouse gas increases, is now for larger than the year-to-year variability in global average temperatures caused by naturally occurring climate drivers”. “The year 2021 will be remembered for a record-shattering temperature of nearly 50°C in Canada, comparable to the values reported in the hot Saharan Desert of Algeria, exceptional rainfall, and deadly flooding in Asia and Europe as well as drought in parts of Africa and South America.”
