Cities are vulnerable to heatwaves. But green spaces can help more than we thought

[hauntedheadnc]

As the climate changes, cities scramble to find trees that will survive

...Urban arborists say planting for the future is urgently needed and could prevent a decline in leafy cover just when the world needs it most. Trees play a crucial role in keeping cities cool. A study published in 2022 found that a roughly 30 percent increase in the metropolitan canopy could prevent nearly 40 percent of heat-related deaths in Europe. The need is particularly acute in marginalized communities, where residents — often people of color — live among treeless expanses where temperatures can go much higher than in more affluent neighborhoods.

While the best solution would be to stop emitting greenhouse gases, the world is locked into some degree of warming, and many regional governments have begun focusing on building resilience into the places we live. Urban botanists and other experts warn that cities are well behind where they should be to avoid overall tree loss. The full impact of climate change may be decades away, but oaks, maples, and other popular species can take 10 or more years to mature (and show they can tolerate a new climate), making the search for the right varieties for each region a frantic race against time.

***

To find solutions, researchers are studying which trees could do better than those currently struggling in rapidly warming cities, with an eye toward species that have already adapted to drier regions hundreds or even thousands of miles away. In Canada, for example, scientists have matched trees from the northern United States with the expected climates in cities including Vancouver, Winnipeg, and Ottawa. Urban foresters in Sydney are considering the trees in Grafton, an Australian city about 290 miles closer to the equator.