MADRID, 19 (EUROPEAN PRESS)
2021 was one of the seven warmest years on record, according to six leading international data sets consolidated by the World Meteorological Organization (WMO).
This figure occurs despite the fact that average global temperatures cooled temporarily due to successive La Niña events at each end of the year.
The HadCRUT5 dataset is compiled by the UK Met Office and the University of East Anglia, with support from the US NCAR (National Center for Atmospheric Research). HadCRUT5 is the most recent data set to report its global findings for 2021. It shows that the year was 0.76 +/- 0.04 degrees Celsius above the 1961-1990 average, making it sixth most warm (along with 2018).
Compared to the pre-industrial global reference period, the year was 1.1 +/- 0.1 degrees Celsius above the 1850-1900 average. This aligns extremely well with figures already published by other international centers.
The WMO uses six international data sets to provide an authoritative assessment of global temperature change. They reported that 2021 was about 1.11 +/- 0.13 degrees Celsius warmer than the 1850-1900 average based on an average of the six data sets. 2021 is the seventh consecutive year (2015-2021) in which the global temperature has been more than 1.0 degrees Celsius above pre-industrial levels, based on all data sets used by the WMO.
The ranking of individual years often depends on small or marginal differences between years and may vary slightly between data sets. However, long-term warming is clear. Since the 1980s, each decade has been warmer than the last and this is expected to continue.
The seven warmest years have all been since 2015, with 2016, 2019 and 2020 in the top three. An exceptionally strong El Niño event occurred in late 2015 and continued into early 2016.
Dr Colin Morice of the Met Office said: “2021 is one of the warmest years on record and continues a series of measurements of a world that is warming under the influence of greenhouse gas emissions. This extends a streak of remarkably warm years “from 2015 to 2021: the seven warmest years in more than 170 years of measurements.”
Professor Tim Osborn, from the University of East Anglia, said in a statement: “Each year tends to be a little below or a little above long-term underlying global warming. Global temperature data analyzed by the Met Office and the UEA Climate Research Unit shows that 2021 was slightly below, while 2020 had been slightly above the underlying warming trend. Every year, including 2021, is consistent with predictions of warming due to human activities.”
“Back-to-back La Niña events mean that 2021 warming was relatively less pronounced compared to recent years. Even so, it was still warmer than previous La Niña-influenced years. The overall long-term warming as a result of greenhouse gases is now much larger than the year-to-year variability caused by natural climatic factors,” said WMO Secretary-General Petteri Taalas.
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.