Europe is in the grip of a heatwave, with temperatures soaring above a scorching 40°C with wildfires burning, even in the Swiss Alps.
The searing heat follows the setting of a new global temperature record earlier this month, when the world’s average temperature reached 17.18°C – the highest recorded.
These events shouldn’t come as a surprise. What we are seeing is warnings made by climate scientists decades ago now coming true.
The UK isn’t immune. Last month, it experienced its hottest June on record since 1884, with an average temperature of 15.8ºC, according to the Met Office.
We felt it directly at The James Hutton Institute’s campus in Invergowrie, near Dundee, where a June mean of 15.1°C was recorded – the hottest June since our records started in 1954.
Across Scotland, the June heat (a mean of 14.3°C, 2.7°C above the long-term average) was combined with increasing water scarcity alerts from the Scottish Environmental Protection Agency (Sepa), which had most of Scotland on alert level for water scarcity by the end of June.
These records might seem like blips. After all, we’ve had hot days and hot Junes before; the previous UK record for the hottest June was jointly held by 1940 and 1970. The difference now is that this is going to happen more frequently and previous extremes will become the future norm.
Our research at the Hutton shows summers in Scotland will become hotter and drier, particularly August and September, due to lower rainfall along with warmer temperatures increasing evaporation, so less water in soils. Conversely, winter rainfall has already increased by amounts larger than those projected by climate models for the future (to 2050).
Why does this matter? These trends combined have significant implications for people and how nature functions. The heat creates uncomfortable conditions for humans, and impacts crop yields and even insect development, on which our crops and wider ecosystems rely. With warmer weather, people are outside more, having barbecues or bonfires, creating an even greater risk of wildfire.
Higher temperatures and low water levels impact river life. Brown trout stop feeding at temperatures above 20°C and sustained water temperatures above 30°C are lethal.
A study by the Hutton looking at the River Spey found that river temperatures had already increased over the last century by 2-3°C, with a high of 27.5°C seen in June 2018 (when the study ended). More than 30 days of low flow – caused by low river levels – can also be catastrophic, says SEPA.
There are things that can be done to mitigate these risks, particularly reducing our emissions. The science we do is designed to help underpin these efforts with robust evidence. This includes working on ecosystem restoration, particularly peatlands, wetlands and woodlands that help store water, to reduce flood risk.
It also includes how to restore river catchments through riverbank woodland to provide the vital shade needed to keep ricers cool. All of which is also beneficial for biodiversity.
There’s a lot of work to be done and it needs to be done at scale and pace to build the resilience we need into our natural ecosystems in the face of the changing climate.
Dr Mike Rivington is senior scientist, The James Hutton Institute
