Atlanta, GA (August 17, 2012) – After a dry, hot summer, trees are taking center stage as a tool to mitigate urban heat islands and generally help cities adapt to a changing climate. A series of articles from across the globe feature cities that are using trees and greenery to help cool things down right now—and to plan for a future of warmer weather, more drought, and health concerns related to rising urban temperatures.
An NPR report on combating the heat island effect, features initiatives in Atlanta that are using trees, gardens, and green spaces to create a kind of outdoor air-conditioning. At Ebenezer Baptist Church, a two-block community garden provides local food production, but also an island of calm that helps offset some of the heat that builds up in the city. And urban trees are providing shade and evaporating water through their leaves, having a cooling effect on city streets.
To preserve Atlanta’s existing trees, a flock of sheep and goats are being recruited to eat kudzu, the most invasive plant in the Southeast, across a 58-acre urban forest. Trees Atlanta has organized and hired an urban shepherd to have his flock cut back the kudzu and preserve the trees. A thick canopy of trees can drop air temperature by 20 or 30 degrees, compared with a paved parking lot. Trees Atlanta also plants 3,000 trees and 3,000 saplings each year.
In Toronto, officials are not sure how their 116 different species of trees growing in the city will fare as the climate changes. But as temperatures increase, the range of where they can plant certain species will shift. And they rely on trees to take up the carbon coming out of cars and help sweep up air pollution. Trees are also absorbing and filtering rain water, and reducing air temperature. Toronto officials consider their $7 billion green infrastructure as important as their electrical grid and stormwater systems for helping to survive extreme weather.
And presentations delivered at the World Conservation Congress in Jeju, South Korea reported on studies from across the globe that are looking to trees to help adapt to a warming world. In some cities it is 10 degrees Celsius higher than just a few miles outside the city. While studies acknowledge the potentially high cost of greening, they recommend a 50 percent increase in residential tree cover and acknowledge the use of trees to help reduce energy costs.
Just add trees: How greening concrete jungles will help us adapt to a warming world
The benefits of trees in avoiding and adapting to climate changes
As temperatures rise, cities combat ‘heat island’ effect