Summer storms over Europe have become weaker and less frequent over the past few decades, but if this trend continues it is likely to lead to more intense heatwaves and droughts according to climate scientists.
A study by researchers at the Potsdam Institute for Climate Impact Research in Germany found a link between the melting sea ice of the Arctic caused by climate change, and the tendency for storm activity in summer over Europe to be less intense.
They believe it is linked with a weakening of the jet stream, a flow of high-altitude air from west to east, which is causing summer storms to become weaker and less frequent and heat-waves to become more severe, such as the hot summer over western Russia in 2010 which caused devastating crop failures and wildfires.
1/7 Coastal systems and low-lying areas
Flood damaged streets in Queens, New York where the historic boardwalk was washed away due to Hurricane Sandy in 2012. The report predicts that by the end of the century “hundreds of millions of people will be affected by coastal flooding and displaced due to land loss”
2/7 Food security
Widespread drought devastated a corn crop on a farm near Bruceville, Indiana in 2012. The report forecasts that climate change will reduce median yields by up to 2 per cent per decade for the rest of the century
3/7 The global economy
The Evening Standard headline board showing the words 'Black Friday Shares Crash' in London in October 2008 in London. The report warns a global mean temperature increase of 2.5C above pre-industrial levels may lead to global aggregate economic losses of between 0.2 and 2.0 per cent
4/7 Human health
A child suffering from malnutrition and diarrhoea is seen at the Banadir hospital in the Somalian capital of Mogadishu in 2009. Climate change will lead to increases in ill-health in many regions, with examples including an increased likelihood of under-nutrition.
5/7 Human security
A Muslim migrant holds his son as they are detained at the Immigration Police Office on the Thai-Malaysian border in March 2014. The report states that climate change over the 21st century will have a significant impact on forms of migration that compromise human security
6/7 Freshwater resources
A villager walks through a parched paddy in Tianlin county, China in 2012. The report finds that climate change will “reduce renewable surface water and groundwater resources significantly in most dry subtropical regions"
7/7 Unique landscapes
Machair, a grassy coastal habitat found only in north-west Scotland and the west coast of Ireland, is one of the several elements of the UK’s “cultural heritage” that is at risk from climate change
“When the great air streams in the sky above us get disturbed by climate change, this can have severe effects on the ground,” says lead-author Dim Coumou.
“While you might expect reduced storm activity to be something good, it turns out that this reduction leads to a greater persistence of weather systems in the northern hemisphere mid-latitudes,” said Dim Coumou of the Potsdam institute, and lead author of the study in the journal Science.
Many previous studies have focused on winter storms, which tend to be more damaging, but summer storms play a role in preventing the onset of a long heatwave that leads to drought.
“In summer, storms transport moist and cool air from the oceans to the continents bringing relief after periods of oppressive heat. Slack periods, in contrast, make warm weather conditions endure, resulting in the build-up of heat and drought,” Dr Coumou said.
“From whichever angle we look at the heat extremes, the evidence we find points in the same direction. The heat extremes do not just increase because we’re warming the planet, but because climate change disturbs airstreams that are important for shaping our weather,” he said.
“The reduced day-to-day variability that we observed makes weather more persistent, resulting in heat extremes on monthly timescales. So the risk of high-impact heatwaves is likely to increase,” he added.Reuse content