London as hot as Barcelona?

New study: London could be as hot as Barcelona by 2050

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Will London be as hot as Barcelona by 2050?

By Daniel J. McLaughlin

London could be as hot as Barcelona is today in the next 30 years, according to new research.

While the rise in temperatures sounds like a nice treat for Londoners, it is a worrying symptom of global heating - and it could have disastrous consequences.

Other researchers have stressed the dangers of the climate crisis - but added that the comparisons between London and Barcelona could be "too simplistic".

The Claim

Time Out reports that London could have a Mediterranean climate by 2050 - and that's not good news.

New research by the Crowther Lab in Zurich claims that in 30 years, London will have a similar climate to that of Barcelona today.

They found that the average annual temperature in London will go up by 2.1°C, and the maximum temperature of the warmest month in the year could increase by 5.9°C.

The peak temperature from last year, in July, was 34°C - this could rise to 40°C by 2050.

The capital will not be the only city "expected to suffer potentially disastrous consequences as a result of global heating".

Around 80 per cent of cities across the world will undergo dramatic changes in climate - and 104 cities are predicted to experience climates that they have not seen at all previously.

The Counterclaim

However, Robert Wilby, a professor of hydroclimatic modelling at Loughborough University, is sceptical about the predictions.

In an article for The Conversation, the urban heat researcher argues that like-for-like comparisons between cities - in this case, London and Barcelona - are "just too simplistic".

He explains: "This is because cities make their own climates according to their unique layouts, building materials, artificial heat sources, amounts of open or green spaces, and types of water feature."

Wilby notes that compact cities tend to be hotter cities. Barcelona has one of the highest population densities in Europe - at about 16,000 per square kilometre. This is more than the 10,000 or so recorded by inner London boroughs.

On the other hand, gardens, parks and water can offer cool refuges for people and biodiversity. Around two-thirds of Greater London is already occupied by these.

He writes: "For instance, satellite observations reveal that on a hot summers day Richmond Park – a large space on the western edge of the city known for its deer – can be about 10°C cooler than parts of the more central Southwark, Lambeth and Westminster.

"Even in these central boroughs, temperatures are chillier along the Thames embankment than just a few hundred metres away."

The Facts

Around the world, the Earth's average temperature has risen more than 1°F (0.8°C) over the past century - and it is twice that in parts of the Arctic.

Most of the warming has occurred in the past 35 years, with the five warmest years on record taking place since 2010, according to NASA.

The warmest year on record was 2016 - with eight of the 12 months in that year, from January to September (with the exception of June), being the warmest on record for those respective months.

The Union of Concerned Scientists report that every one of the past 40 years has been warmer than the 20th century average - and the 12 warmest years on record have all occurred since 1998.

This is caused by the increase of carbon dioxide (CO2) levels in the atmosphere. Detailed measurements of the levels have been taken continuously since the late 1950s. In 2017, they were 28 per cent higher than in 1959.

They explain: "CO2 absorbs heat reflected from the Earth's surface - heat that would otherwise pass freely into space. The CO2 then releases that heat, warming the Earth's atmosphere.

As CO2 levels increase, the pace of warming accelerates. Satellite measurements confirm that less heat is escaping the atmosphere today than 40 years ago."

This global heating is caused primarily by humans. Other heat-trapping gases may play a role, but CO2 is the main contributing factor - and human activity is to blame for the increase in these levels.

The CO2 emitted by burning fossil fuels, such as coal, natural gas and oil, has a special chemical "fingerprint". The extra CO2 in our atmosphere bears that unique fingerprint.

There is also a greater than 95 per cent probability that the current, unprecedented warming is the result of human activity since the mid-20th century. "There is no question that increased levels of greenhouse gases must cause the Earth to warm in response," NASA adds.

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