If you're looking for a reason to care about tree loss, this summer's record-breaking heat waves might be it. Trees can lower summer daytime temperatures by as much as 10 degrees Fahrenheit, according to a recent study.
But tree cover in US cities is shrinking. A study published last year by the US Forest Service found that we lost 36 million trees annually from urban and rural communities over a five-year period. That's a 1% drop from 2009 to 2014.
If we continue on this path, "cities will become warmer, more polluted and generally more
unhealthy for inhabitants," said David Nowak, a senior US Forest Service scientist and co-author of the study.
Nowak says there are many reasons our tree canopy is declining, including hurricanes, tornadoes, fires, insects and disease. But the one reason for tree loss that humans can control is sensible development.
"We see the tree cover being swapped out for impervious cover, which means when we look at the photographs, what was there is now replaced with a parking lot or a building," Nowak said.