Climate crisis behind heat extremes in India, UK: Study
The Climate crisis is impacting global atmospheric circulation patterns making unprecedented heat extremes possible across the world, an international team of leading climate scientists who are part of the World Weather Attribution (WWA) network said on Thursday.
WWA, which presented its analysis on the July UK heat wave spell on Friday, said this (the spell) was made 10 times more likely due to climate change. Models analysed by the group show that the same event would have been at least 2 degrees C less hot in a 1.2 degree C cooler world or during pre-industrial times.
The rise in average global temperatures is changing atmospheric and global circulation patterns leading to a series of heat extremes this year in different parts of the world starting with the spring heat wave spell in India and Pakistan; the UK heat extreme in mid-July; and now extreme heat stress in the US, it added.
India and Pakistan’s MarchApril extreme heat spell was unprecedented, made about 30 times more likely because of human-caused climate change, a rapid attribution analysis by an international team of leading climate scientists who are part of the World Weather Attribution network said in May.
On July 18 and 19, an exceptional heat wave affected large parts of the UK. It was the first time that temperatures of 40 degree C and above were forecast in the UK according to WWA.
Like India’s heat spell which was followed by an extremely dry pre-monsoon season, the heatwave event in the UK was also very dry and followed a longer dry spell.
July this year was the UK’s driest since 1911. Drought conditions have also been widespread across continental Europe in recent months, according to the report.
But the UK and India’s heat wave spell has been estimated to have a return period of around 100 years in today’s climate of 1.2C global warming making both unusually rare-- 1 in a 100 year events.
The impact of these events has been vastly different in the two countries. While at least 90 people have died in India and Pakistan as a result of the heatwave, a toll that will almost certainly increase substantially with more reporting, there are projections of excess mortality of over 840 people in UK for July 18 and 19 and increase in hospitalisations, infrastructure damage, and psychosocial effects.
Climate scientists said all of these heat extremes that posed a massive public health crisis were linked by certain global atmospheric patterns.
“We have one atmosphere. These events are influenced by the global circulation pattern and affected by certain regional and local parameters. The changing behaviour of the jet stream influences heat waves in the extra-tropics but in tropical countries like India there are other factors too,” said M Mohapatra, director general of IMD.