The World Meteorological Organization announced that the average global temperature for 2020 was nearly 1.3°C above pre-industrial levels, concluding earth’s warmest 10-year period on record. 2020 is also the first year that the new HadCRUT5 dataset has been used by the World Meteorological Organization to assess global surface temperature change.
Data from the HadCRUT5 global temperature series, produced by the Met Office, University of East Anglia and National Centre for Atmospheric Science, shows that 2020 placed second in the top three warmest years on record. Regionally, notable warming was observed in northern Asia extending into the Arctic, and in parts of eastern Europe and Central America.
The high ranking of 2020 in the HadCRUT5 dataset’s record is despite a transition into La Niña conditions late in the year. La Niña is a naturally occurring climate cooling phenomenon, which typically suppresses global temperatures.
The new dataset improves the coverage of temperature information in the early record, and in other areas that are data-sparse, by updating sea-surface temperature measurements, significantly increasing the number of weather stations used and the application of statistical methods. HadCRUT5 is part of a collection of datasets that make up the World Meteorological Organization’s estimates of climate change.
Monitoring global average temperature is important as it is the benchmark used to create and measure governmental policy commitments, such as the Paris Agreement. The temperature figures will be incorporated into the final World Meteorological Organization report on the State of the Climate in 2020, which will be issued in March 2021.
For the last 50 years, our global climate has been warming at about 0.2°C each decade. This underlying warming, due primarily to society’s use of coal, oil and gas, is what matters for monitoring climate change and tracking our progress against the goals of the Paris Agreement, more so than the warmth of an individual year. Nevertheless, it is notable that we have just experienced, globally, the second warmest year of the warmest decade on record.
Tim Osborn, Director of the Climatic Research Unit at the University of East Anglia
The temperature ranking of individual years represents only a snapshot of a much longer-term trend of warming. The dramatic rise in global temperatures is caused by human emissions of greenhouse gases into the atmosphere, which started in the 1800s when humans began to burn fossil fuels during the industrial revolution.
The effects of human-induced climate change are not limited to surface temperature. Warming of the climate system is seen across a range of climate indicators that build a holistic picture of climate change far beyond our expectations from natural variability across the land, atmosphere, oceans and ice.