Mayor Sadiq Khan will spend millions planting trees to cool down London
Key Points
- London Mayor Sadiq Khan will spend millions funding new trees and green spaces in London to cool down the capital.
- Due to the 'urban heat island' effect, London can be up to 10 degrees hotter than the rural areas surrounding it.
- The Mayor has committed over £1 million to planting 5,000 new trees to mitigate this effect and a further £3 million to supporting green space projects in the city.
London Mayor Sir Sadiq Khan announced he will spend £1.1 million planting trees across the city to tackle its ‘urban heat island’ effect.
The Mayor said he would allocate the funds to a large-scale tree equity project that will make it easier to plant trees in hotter and more polluted neighbourhoods, and will enable the planting of 5,000 new trees in the city.
Planting trees is one of the most effective ways to mitigate the ‘urban heat island’ (UHI) effect, which leads to an urban centre becoming much hotter than its surrounding countryside.
This phenomenon is called a ‘heat island’ because it results in the warmer city air lying in a ‘sea’ of cooler rural air.
The difference in temperature between urban and rural areas is usual bigger in the evening and when winds are weak, such as during the heatwaves seen in London last year.
London can get 10 degrees hotter than surrounding areas
The UHI effect is strong in London. According to data from the London Climate Ready Partnership (LCRP), city temperatures in London were up to 10 degrees hotter than the surrounding rural areas during the summer heatwave of 2003.
These higher temperatures are due to the increased capacity of roads, buildings, pavements and other urban surfaces to absorb and trap heat.
With the climate continuing to warm and the UK continuing to see the highest average summer temperatures on record in recent years, tackling London’s UHI effect will help to mitigate the effect of the increasingly warm temperatures seen in Britain.
Planting trees is one way to provide shade and mitigate the effectiveness of urban surfaces at trapping heat during hot summers.
The image below shows the impact of the ‘urban heat island’ effect in London during the 2003 summer heatwave.
Investing in London’s green spaces
The Mayor’s funding is part of a larger package of £4.6 million that Khan has announced he will invest in boosting London’s green and blue spaces.
£3.5 million will be allocated to local community projects that are aimed at planting trees, improving access to green spaces, and supporting communities in transforming local spaces.
These projects include training young people to support the environment, funding the transformation of two Hackney sites into wildlife gardens, and helping homeless people to learn gardening skills.
“I am delighted to award the second round of funding from my Green Roots Fund to support 33 brilliant organisations and community groups to deliver more green, blue and climate resilient spaces for our city,” Khan said.
“In addition, communities in areas most affected by rising temperatures will benefit from thousands of new trees.”
“Everyone should have access to nature, which is why we’re empowering London’s communities to transform their neighbourhoods through these new blue and green spaces,” he said.
