The record-breaking heat in the UK in 2022 was made 160 times more likely by the climate crisis, indicating the dominant influence of human-caused global heating on Britain.
Last year has been confirmed as the UK’s hottest on record, with the average annual temperature passing the 10C mark for the first time. Scientists at the Met Office calculated that such heat is now expected every three to four years. Without the greenhouse gases emitted by humanity, such a warm year would be expected only once every five centuries.
The 10.03C recorded in 2022 beat the previous record of 9.88C set in 2014, and is 0.89C above the average of the last three decades. All the UK nations set new record annual temperatures.
The world’s longest instrumental record of temperature is the 364-year-long Central England Temperature and this also set a new high in 2022 of 11.1C.
Scientists were shocked in July when the daily temperature record passed 40C for the first time, obliterating the previous high of 38.7C. The hot summer led to thousands of early deaths. A cold spell in December made little difference to the overall average annual temperature.
The scientists estimated the influence of global heating on the UK’s record hot year by comparing the results of climate models reflecting today’s high levels of carbon dioxide with models representing the pre-industrial period, when CO2 levels were much lower.
Dr Nikos Christidis, a Met Office climate attribution scientist, said: “We calculated that by the end of the century, under a medium [future] emissions scenario, a UK average temperature of 10C could occur almost every year.”
Guardian analysis in August revealed how people across the world were losing their lives and livelihoods because of more deadly and more frequent heatwaves, floods, wildfires and droughts brought by the climate crisis.
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Dr Mark McCarthy, at the Met Office, said: “The UK surpassing an annual average temperature of 10C is a notable moment in our climatological history [and] comes as no surprise. Since 1884, all 10 years recording the highest annual temperature have occurred from 2003. It is clear from the observational record that human-induced global warming is already impacting the UK’s climate.” Nine of the 10 coldest years on record occurred more than a century ago, the Met Office data showed.
“Even with the influence of climate change we don’t expect every year to be the hottest on record from now on,” McCarthy said. “Natural variability of the UK climate means there will always be some variation year to year. However, looking at longer term trends it is easy to pick out the influence climate change is having over time.”
Prof Richard Allan, at the University of Reading, said: “Higher temperatures in the UK are contributing to more severe heatwaves, droughts and wildfires but also more intense rainfall events and flooding. These impacts will become progressively worse until global temperatures are stabilised by cutting global carbon emissions to net zero.”