That ‘gross putrescent fluid’ in air? Blame trees

“People had initially believed that axing American’s wilderness into fields had improved its climate, as summers apparently became cooler and winters less harsh.

“[North Carolinian] Hugh Williamson, for example  — one of the delegates who had visited Bartram’s garden during the Constitutional Convention  — had, in 1770, told the members of the American Philosophical Society that forests created an air ‘charged with a gross putrescent fluid,’ creating a desperately unhealthy atmosphere for mankind.”

— From “Founding Gardeners: The Revolutionary Generation, Nature, and the Shaping of the American Nation by Andrea Wulf (2012)

Well into the 21st century, scientists and politicians are still debating tree pollution.