Climate change is destroying U.S. cities’ forests, study says

Written by By Esme Montero, CNN

About 34 million trees are being lost in U.S. cities every year as development replaces natural areas, new research indicates.

The “urban forests” — as they’re known — have been systematically destroyed and replaced with office parks, shopping centers and highways by the year.

According to the report , published Tuesday by the journal Nature Climate Change , they will decline to 5% of the standard urban forest by 2100.

Cities are “clearly important ecosystems that are very important for climate resilience, flood resilience, storm water, recreational value,” said lead author Zachary Griffith of the University of Waterloo in Canada.

‘Industrial civilization is a unique phenomenon in the history of the planet’

Researchers “have developed models that show that the absence of a diverse array of trees and shrubs coupled with a predominance of a few ecosystems such as heavy metal ores, asphalt pavements, plastic-lined green roofs,” will likely result in more frequent devastating weather events, climate change, urban heat island effect and less tree canopy cover, he said.

“By removing biodiversity from many landscapes, buildings and street landscapes, most of these (benefits) are eliminated,” the report notes.

Are we really happy living in a post-apocalyptic landscape?

The human impacts were not always so dire.

“So far in history there’s been a lot of improvement in the environment, really throughout the history of human civilization, and the rate at which our impact has increased is unprecedented,” Griffith said.

There are still huge gaps

The report found that even while urban areas are losing trees, there are still 40 million more forests along waterways than people

Moreover, those cities that are closest to farms on average have bigger urban forest cover than those farther away from them, the report said.

And while there are still huge gaps, cities that are fast reforesting with native plants and trees, are faster reforesting and not experiencing the same types of stresses, Griffith said.

“The idea is that we want to move from this of a ‘sore loser’ to the next level, really helping to ‘overturn the paradigm’ of the declining landscape,” Griffith said.

There are examples of cities moving beyond landscapes to protect people.

Chiang Mai, Thailand, a city with a population of more than 3 million people has planted some 4 million trees over the past 18 years, according to the city’s mayor.

But Griffith stressed that it’s going to take governments and other urban planners to “show leadership” to create the “smart growth” that would reverse the loss of the urban forests.

“Industrial civilization is a unique phenomenon in the history of the planet and also in human civilization,” he said.

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