What it's about:
Cities in the United States are losing an estimated 36 million trees each year, according to researchers at the Forest Service.
Tree cover in U.S. urban areas fell by 1 percent between 2009-2014, declining at a rate of around 175,000 acres per year, they said in a study published in the journal Urban Forestry and Urban Greening.
While tree cover experienced a significant reduction across the states, impervious surfaces - such as roads and buildings - increased by 167,000 acres per year, with an estimated 40 percent of the concrete structures surfacing in areas where trees used to grow, the Guardian newspaper reports.
Alabama, Florida and Georgia recorded the greatest annual tree loss, with the latter losing 18,830 acres of trees per year. Only three states - Wyoming, Minnesota and Alaska - experienced no change in tree cover over the five years.
Why it's noteworthy:
The rapid decline in tree cover in U.S. cities has serious environmental, social and economic consequences, the researchers warned. Tree loss could have a detrimental impact on the health and wellbeing of 80 percent of the U.S. population who live in urban areas, they said.
Trees reduce carbon emissions, improving air and water quality in urban areas, they said. Urban forests can save energy by reducing air conditioning needs by 30 percent and heating needs by up to 50 percent, according to the Food and Agriculture Organisation of the United Nations (FAO).
Green areas in cities also improve people’s mental health by significantly reducing stress and anxiety, Hiroto Mitsugi, Assistant Director-General of FAO’s Forestry Department, wrote in an opinion piece published on Zilient in March.
One Toronto study found that having just 10 more trees in a city improved a person’s health in the same way that a $10,000 increase in their annual income or being seven years younger would, he noted.
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