Untethered weather?

Billy Bland was staring at a riverbed without water. At 76, he had lived in Borrowdale on the River DerwentA river in Derbyshire, England. all his life.  But in the middle of June its nickname - "the wettest place in England" - seemed like a bad joke. "This dry spell is earlier and longer than I can remember," he told The Guardian. "I don't remember the beckA stream. The word is most commonly used in northern England. ever being as low."

According to Ruth Mackay of West Cumbria Rivers Trust,¹ this was the third year in a row that large parts of the river had dried out: "If a drought impacts a river, there is usually chance to recover in the succeeding years. But when it happens year after year, it becomes catastrophic for the wildlife that depend on it."

Even if the water does not disappear completely, she says, very hot weather can affect the whole ecosystemA complex network of living things that rely on each other to survive. - "from the insects that live in the water to the fish, right through to the otters and the birds".

Some die because warmer water does not carry enough oxygen for them: temperatures of 22 to 24C can kill fish. And if water levels are low, there is a higher concentration of pollutants such as sewage and fertilisers from farmland.

"The reports of the number of fish death incidents in rivers for this time of year has been unprecedented," says Mark Owen of the Angling Trust.

Plants and insects also suffered in the June heat. Flowers such as orchids wilted, so there was less nectarA sugary fluid within flowers to encourage pollination by insects and other animals, collected by bees to make into honey. and pollenA fine powder produced by flowers that fertilises other flowers. for bees and butterflies to eat.  

When the Met OfficeThe Meteorological Office is the United Kingdom's national weather service. It was established in 1854 to provide a gale warning service for shipping. analysed the high temperatures with a supercomputer, it found that the chances of June being hotter than ever before had at least doubled since the 1940s.

According to the European Environment Agency (EEA), over half of Europe has suffered extreme droughts in both summer and winter since 2018. Last summer saw a much reduced yield from crops like corn, maize, soybeans and olives, and the EEA believes droughts will cost Europe's economy at least £29bn a year by 2300.

It also expects the danger of wildfires to increase, as a result of hot, dry periods with strong winds. Last year they devastated over 5,000 square kilometres - twice the area of LuxembourgA small country in Western Europe with a population of 640,000. .

Heatwaves claim more human lives than any other form of extreme weather. Old people and those who live in cities are particularly vulnerable.

A study of 43 countries² estimated that 37% of deaths caused by them would not have happened without climate change. Warmer weather is also encouraging the spread of disease-carrying insects such as ticks and mosquitoes.

As well as the extreme weather, experts are noticing more subtle changes. In the US, winters are warming faster than summers, and nights are warming faster than days.

But there are things we can do to mitigateMake something bad less serious or dangerous. the effect of very hot weather. The EEA recommends increasing the number of trees and lakes in cities. Farmers can grow different crops and sow them at different times. Gardeners can provide water for insects and let grass grow longer to create a protective habitat for them.

Is this the new normal?

Yes: According to the European Environment Agency, heatwaves throughout Europe "are getting more frequent, longer and more intense and will continue to do so under all climate scenarios".

No: Weather has a lot of natural variability, so we might go back to cooler summers. Studies of a Russian heatwave in 2010 and Indian one in 2016 concluded that climate change was not responsible.

Or... It is very hard to tell. Weather systems are so complicated that scientists struggle to say which extreme events are caused by climate change and which would have happened anyway.