UK Met Office Will Cut Number Of Heatwaves By Increasing Temperatures Needed To Declare One
In a morass of bad climate news, from collapsing ice shelves to the potential resurgence of coal in Europe, there is a sliver of good news. There could be fewer heatwaves declared in England this summer. However, this won’t be due to a reversal of global heating, or a summer cool snap across Britain. Instead, the Met Office is changing the definition of a heatwave in eight counties by raising the required temperature threshold.
Rather than marking some new scientific standard for heatwaves, this new definition is simply a normalisation of higher temperatures in the UK. It will probably lead to fewer news reports and official statistics about heatwaves, without representing any actual respite from the record high temperatures of the past decade. It seems it’s easier to change the optics of climate breakdown than it is to address runaway warming.
The shift varies from county to county. In six southern counties, the boundary has nudged up from 27C to 28C, and jumps from 26C to 27C in Lincolnshire and from 25C to 26C in the East Riding of Yorkshire. Heatwave limits were originally calculated based on the climate between 1981 and 2010, while the new thresholds will use a 1990-2020 average.
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Take as one example the literal shifting of baseline years used to calculate emissions reductions. Some nations compare their net zero targets against emissions in 1990, others in 2005 (the latter a higher emissions year). Calculating from a higher point makes subsequent annual cuts appear deeper and more impressive in percentage points, even though there is no material difference in carbon reduction. Similarly, the lifting of the heatwave bar could play into the hands of climate deniers by implying there are fewer extreme heat events in England.
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https://www.theguardian.com/commentisfree/2022/mar/30/met-office-fewer-heatwaves-england-optics-action