The last seven years have been the hottest on record globally, according to the European Union’s climate monitoring service.
In its latest annual assessment, the Copernicus Climate Change Service (CCCS) confirmed that 2021 had joined the unbroken warm streak since 2015.
It found that last year was the fifth warmest on record globally, marginally warmer than 2015 and 2018. Accurate measurements go back to the mid-19th century.
The annual average temperature was 1.1 to 1.2 degrees Celsius above pre-industrial levels, measured between 1850 and 1900, CCCS said.
The rise was despite the cooling effect of the natural La Nina weather phenomenon.
Overall, the monitoring service found the last seven years “have been the warmest years on record by a clear margin”.
“2021 was yet another year of extreme temperatures with the hottest summer in Europe, heatwaves in the Mediterranean, not to mention the unprecedented high temperatures in North America,” said CCCS director Carlo Buontempo.
“These events are a stark reminder of the need to change our ways, take decisive and effective steps toward a sustainable society and work towards reducing net carbon emissions.”
The CCCS also monitored atmospheric concentrations of the planet-warming gases carbon dioxide and methane, finding that both had increased with no sign of a slowdown.
Methane particularly has gone up “very substantially”, to an annual record of about 1,876 parts per billion (ppb).
Growth rates for 2020 and 2021 were 14.6 ppb per year and 16.3 ppb per year, respectively. That is more than double the average annual growth rate seen over the previous 17 years.
But an array of human-caused and natural sources made it hard to pinpoint why there had been such a strong increase in recent years, C3S said.
Methane (CH4) is the gas most responsible for global warming after CO2. While more short-lived in the atmosphere, it is, however, more potent than CO2.
Natural sources include wetlands, while human-induced sources are leaks from natural gas and oil production, coal mining and landfills, as well as rice paddies, livestock and manure handling.