Saturday, Oct 08, 2022

What's Causing Heatwave In UK? Britain's Hottest Day Is A Wake Up Call For Climate Change

On Tuesday, Britain saw its hottest day with the UK Met Office registering a provisional reading of 40.2 degrees Celsius. Before Tuesday, the highest temperature recorded in Britain was 38.7 C, a record set in 2019.

Heatwave in the UK
Heatwave in the UK AP Photos

Even as monsoons brought respite from a prolonged heatwave in several parts of India, the heatwave seems to have moved to European nations in an unprecedented phenomenon that many are seeing as a direct result of climate change. This week, Britain shattered its record for highest temperature ever registered Tuesday amid a heat wave that has seized swaths of Europe — and the national weather forecaster predicted it would get hotter still in a country ill prepared for such extremes.

Extreme heatwave

The heatwave across Europe has led to unusually hot, dry weather that has gripped the continent since last week, triggering wildfires from Portugal to the Balkans and leading to hundreds of heat-related deaths. Images of flames racing toward a French beach and Britons sweltering — even at the seaside — have driven home concerns about climate change

Reports of Britain, typically a temperate nation, sweltering in heat have left alarm bells ringing across the world.

On Tuesday, Britain saw its hottest day with the UK Met Office registering a provisional reading of 40.2 degrees Celsius (104.4 degrees Fahrenheit) at Heathrow Airport — breaking the record set just an hour earlier. Before Tuesday, the highest temperature recorded in Britain was 38.7 C (101.7 F), a record set in 2019.

The nation watched the mercury rise with a combination of horror and fascination. The sweltering weather has disrupted travel, health care and schools in a country not prepared for such extremes. A huge chunk of England, from London in the south to Manchester and Leeds in the north, remained under the country's first “red” warning for extreme heat Tuesday, meaning there is danger of death even for healthy people.

London reeling

London streets saw less traffic, as many heeded advice to stay out of the sun, and trains ran at low speed out of concern rails could buckle, or did not run at all. The British Museum — which has a glass-roofed atrium — planned to shut its doors early. And the Supreme Court closed to visitors after a problem with the air conditioning forced it to move hearings online. Many public buildings, including hospitals, don't even have air conditioning, a reflection of how unusual such extreme heat is in the country better known for rain and mild temperatures.

What's causing the heatwave?

Climate Change

The UK has been heating up consistently over the years, becoming 0.9 degrees Celsius warmer in the past three decades. Average July temperatures in the U.K. range from a daily high of 21 C (70 F) to a night-time low of 12 C (53 F), and few homes or small businesses have air conditioning.

According to experts, heatwaves are becoming more likely and more extreme because of human-induced climate change. The world has already warmed by about 1.1C since the industrial era began, and temperatures are set to keep rising unless sharp cuts are made to carbon emissions. 

Climate experts warn that global warming has increased the frequency of extreme weather events, with studies showing that the likelihood of temperatures in the U.K. reaching 40 C (104 F) is now 10 times higher than in the pre-industrial era. 

There are two in which climate change primarily drives heatwaves. The first is by trapping more heat in the global system. A warmer atmosphere inadvertently leads to more heat extremes. 

The other way in which climate change impacts heatwaves is more dynamic. According to a report in Politico, changes in weather patterns can result in unusual weather phenomena such as rain in dry places or heatwave in cold areas.

High-pressure systems

The likelihood of heatwaves increases during the summer when the what creates high pressure zones in certain areas. In the UK, slower jet streams - core winds that blow from west to east above the Earth's surface and affect the wind and pressure system of it surroundings - can lead to the creation of high-pressure zones that can lead to prolonged high temperatures and dry weather. 

This high-pressure system is called the Azores High, which as per reports has been driving the record heatwave in the UK this year. The Azores High refers to a large, persistent atmospheric high-pressure centre. The system usually develops in the eastern North Atlantic Ocean and Northern Hemisphere during the winter and spring seasons respectively before moving westward during the summer and fall months. As per reports, this system of high pressure has brought scorching air up from North Africa to the UK.

Why the heatwave is dangerous in Europe

Heatwaves driving wildfires

Drought and heat waves tied to climate change have also made wildfires harder to fight.  Hot weather has gripped southern Europe since last week, triggering wildfires in Spain, Portugal and France. Almost 600 heat-related deaths have been reported in Spain and Portugal, where temperatures reached 47 C (117 F) last week.

Thousands of people have been evacuated from their homes and vacation spots in the Gironde region of southwest France since wildfires broke out in tinder-dry pine forests a week ago.

Not built for heat

UK infrastructure, similar to several other European nations, is built for the cold which means it has typically been designed to retain heat during the winter. Now, it must become effective at keeping the heat out in the summer. At present, roughly 20 per cent of existing UK infrastructure is at risk of overheating – and this threat is projected to rise as average temperatures climb, a report in The Conversation noted.

Hot weather strains the pipes that pump water in countries like UK, as well the power lines that deliver energy and the roads and railways. As global temperatures continue to rise, national infrastructure will be challenged as never before in nations like the UK.

(With inputs from Agencies)