May 2, 2019

Study: 40% tree covering can cool urban neighborhoods

Eurek Alert - The idea of the heat island -- that densely built-up urban areas are considerably hotter than the rural and semi-rural landscapes that surround them -- has been extensively studied and is widely accepted by academics and the public.

But a new study by a Concordia researcher takes a closer look at the phenomenon and what can be done to mitigate it. According to Carly Ziter, an assistant professor of biology in the Faculty of Arts and Science, extensive tree canopy cover in an urban area can dramatically reduce the temperatures of their immediate environs -- enough to make a significant difference even within a few city blocks.

"We found that to get the most cooling, you have to have about 40 per cent canopy cover, and this was strongest around the scale of a city block," she says. "So if your neighbourhood has less than 40 per cent canopy cover, you'll get a little bit of cooling, but not very much. Once you tip over that threshold, you really see large increases in how much you can cool areas off."

1 comment:

Anonymous said...

The same principle was used to cool the U of Minn's new (in the '70s) bookstore: it's largely underground, and the windows have deciduous vines covering them, which die back in the winter to admit light and heat, but leaf out in spring to protect from heat.