The global race to turn back the effects of climate change is getting tougher with new data showing 2021 was among the seven hottest years on record.
The average temperature across the planet over the past 12 months was about 1.11°C above the pre-industrial levels recorded from 1850 to 1900. The period was also shown to be the seventh consecutive year where global temperatures had been more than 1°C above pre-industrial levels.
The data was compiled by six leading international data sets consolidated by the World Meteorological Organisation. The same figures are used in its annual State of the Climate reports which inform the international community on global climate indicators.
Global warming and other long-term climate change trends are on track to continue as a result of record levels of heat-trapping greenhouse gases in the atmosphere, the organisation said.
It also said that the trend that began in the 1980s, which shows each decade has been slightly warmer than the previous one, was unlikely to change anytime soon.
The warmest seven years have all been since 2015, with 2016, 2019 and 2020 being the top three. The record global average experienced in 2016 was put down to an exceptionally strong El Nino event. El Nino refers to the warming of the equatorial Pacific Ocean, which has impacts on weather patterns around the world.
The occurrence in 2016 turned out to be in the same class as the biggest such events recorded in the 20th century.
Prof Petteri Taalas, secretary general of the WMO, said 2021 would go down in history for its “record-shattering temperature” range in Canada.
Last summer’s heatwave in the country resulted in the deaths of hundreds of people, most of them elderly.
“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,” Prof Taalas said.
“Climate change impacts and weather-related hazards had life-changing and devastating impacts on communities on every single continent.”
The Copernicus Climate Change Service estimated that 2021 was the fifth warmest year on record while data from the US National Oceanic and Atmospheric Administration said it was nominally the sixth hottest year.
Nasa, Gistemp and HadCrut all had 2021 effectively tied for sixth place while data from the Japanese Meteorological Agency ranked the year as seventh warmest.
The small differences among these data sets indicate the margin of error for calculating the average global temperature.
The main indicators used by scientists to measures changes to the climate are temperature, greenhouse gas concentrations, ocean heat content, ocean pH, global mean sea level, glacial mass and sea ice extent.
“Back-to-back La Nina 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 Nina,” Prof Taalas said, referring to the oceanic and atmospheric phenomenon that is the colder counterpart of El Nino
“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.”
Following the UN Cop26 summit in Glasgow, Scotland, last November, countries shifted gears and made bold commitments to cut their contribution to climate change.