The average temperature of towns and cities around the world could be up to 8.1f (4.5C) warmer than today by the end of the century, researchers claim.
A team from Illinois University applied 26 different complex climate models to urban areas in a first of its kind study, to better understand the impact of climate change.
The world is facing ‘environmental armageddon’ if carbon emissions remain high, warn the US team, who say devastating wether events including extreme droughts and catastrophic floods are inevitable unless action is taken.
Britain would regularly sizzle in temperatures of over 104 degrees Fahrenheit (40C) if the predictions made by the team from Illinois prove to be correct.
The world is facing ‘environmental armageddon’ if carbon emissions remain high, warn the US team, who say devastating wether events including extreme droughts and catastrophic floods are inevitable unless action is taken
Corresponding author Dr Lei Zhao, of Illinois University, said over half the world’s population lives in an urban environment such as a town or a city.
‘Cities also tend to warm more than rural or suburban areas because built surfaces made out of concrete and asphalt absorb more heat and inhibit cooling,’ Zhao said.
‘Incorporating these variables into climate change predictions is crucial for understanding future urban climate – but doing so can be challenging.’
The UN Paris climate change agreement calls on nations to take action to prevent average global temperatures by more than 3.6F (2C) above pre-industrial levels.
That is an average over all areas of the planet, but people in urban areas could be facing more than double that increase within the next 80 years, Zhaeo predicts.
He said: ‘Urban regions across the globe could warm more than 4°C under a high-emissions climate change scenario.’
Based on their study, the team found average warming across the planet will rise by 3.4F (1.9C) even with significant cuts in greenhouse gas emissions.
Dr Zhao said despite occupying only three per cent of the Earth’s land surface, cities will be home to 70 per cent of the population by 2050 and are where major human-perceived climate change impacts will occur by 2100.
‘Many globally recognised environmental problems, such as heat stress, water scarcity, air pollution and energy security, are amplified in built areas through the uniqueness of urban climates and high population density,’ he added.
The phenomenon has been largely overlooked in previous climate change models that have taken a more holistic approach to predicting temperature increases.
Dr Zhao said: ‘Our results can accurately account for the human-perceived impacts of climate change in population hotspots.’
It isn’t all bad news, the study published in Nature Climate Change also predicted a near-universal decrease in relative humidity in cities.
This would make surface evaporation more efficient- suggesting adaptation strategies like urban vegetation could be effective.
Dr Zhao said: ‘Effective urban planning for climate-driven risks relies on robust projections specific to built landscapes.
Based on their study, the team found average warming across the planet will rise by 3.4F (1.9C) even with significant cuts in greenhouse gas emissions
‘Our findings support green infrastructure intervention as an effective means of reducing urban heat stress on large scales.’
The current record for the hottest temperature ever recorded in the UK stands at 101.7F (38.7C) – which was set in Cambridge in July 2019.
The past two summers have seen periods of significant and uncomfortable heat across much of Britain and Europe and without action to reduce carbon emissions, temperatures will increase and hot periods will last longer, the team warned.
Met Office researchers have found the recent hot periods occurred partly as a result of warming gases originating from human activities.
In fact, the use of energy, transport and all the other carbon that we’ve been producing made the heatwave of 2018 around 30 times more likely.
The findings have been published in the journal Nature Climate Change.