Europe heatwave: a number of reasons, climate change most worrying

Why is it so hot

As is true of most such situations, the unusually high temperatures are a result of the combination of global and local factors. On the global scale, climate change has been driving the temperatures upwards, which, in general, is evident across the world.

Considering the average annual temperature, the last eight years have been the hottest ever recorded through direct measurements since the 1880s, a NASA analysis showed. The temperature in 2021 was the sixth highest ever recorded. Most regions of the world have been reporting higher-than-usual temperatures year after year. In the United Kingdom, each month of this year has recorded substantially higher average temperatures compared to normal, or the average of the 30-year period between 1991 and 2020 (see chart). The current heatwave in UK and the rest of Europe, which began in the second week of July, is in keeping with this trend, and was forecast well in advance.

But climate change alone does not fully explain the record-breaking temperatures being seen in Europe. These kinds of unprecedented high temperatures are usually a result of some unusual combinations of local, short-term, warming phenomena which accentuate the already high baselines induced by climate change. In the present case, a low pressure system over the European region has been found to be attracting hot air from northern Africa. An unusual warming in the Arctic Ocean is also said to be playing a role.

“A slow-moving high-pressure area has been, and is still, transporting hot air from North Africa over western and parts of central Europe. The hot air is moving northwards, first affecting Portugal, Spain, France, now the UK, and imminently reaching the Benelux countries (Belgium, the Netherlands and Luxembourg), and western Germany, Switzerland, and northern Italy. It is expected that local/regional temperature records will be broken this week,” the European Centre for Medium Range Weather Forecasting (ECMWF) said in a bulletin on Monday a day before the record-breaking temperature was recorded in Britain.

A similar air circulation phenomenon was seen in June as well, when not just France but Norway and many other countries witnessed record high temperatures. Such local events are often short-lived and their impacts dissipate over a few days. Britain had relief on Wednesday, with temperatures dropping down to an extent. Even in France, the day the 45°C mark was breached, temperature had dipped by as much as 15°C after a few hours.

“Now that the extreme heat is behind us, the UK can look forward to more typical conditions. The introduction of moister air from the Atlantic is triggering the risk of thunderstorms and heavy showers for parts of the UK with a warning in force today (Wednesday) for most of southern and eastern England. There’s a further risk of thunderstorms on Friday but by the weekend it’ll turn drier, brighter and increasingly warm in the south and east of England. Northern and western parts of the UK are set to experience relatively fresher conditions as it turns breezier and wetter here over the weekend,” Dan Suri, a forecaster at UK Met Office, was quoted as saying in a statement.

Climate change, long-term

The worrying part is the rise in temperatures due to global warming. Higher temperatures are being recorded every year and no immediate relief is in sight.

The head of the World Meteorological Organization (WMO) warned on Thursday that the kind of heatwaves being seen in Europe right now would very soon become the new normal.

“In the future, these kinds of heatwaves are going to be normal. We will see stronger extremes. We have pumped so much carbon dioxide in the atmosphere that the negative trend will continue for decades. We haven’t been able to reduce our emissions globally… Heatwaves will happen more frequently because of climate change,” Petteri Taalas, secretary-general of WMO, said in a statement.

The Intergovernmental Panel on Climate Change (IPCC), which brings out the most authoritative analysis of climate change science, has been repeatedly warning of a sharp increase in the frequency and intensity of extreme weather events – rainfall, heatwaves, drought, flooding. The IPCC’s most recent report suggested that global temperatures would most likely go beyond 1.5°C higher than pre-industrial times within a decade.