Leaves of three -- will they let us be?

If you've been out in the woods or fields lately, you might have noticed that invasive poison ivy and its rash-inducing comrades seem to be on steroids, even in places like our urban/suburban backyards. You're not alone. USDA researchers are among those who warn that high levels of CO2 in the atmosphere have a growth-inducing effect on the three-leaved menace. And yes, that atmospheric stew that's brewing is one of the leading causes of climate change.

Poison ivy is actually not an ivy, and for anyone who's made its acquaintance, it's not a friend. But it's not a reason to miss out on hikes and paddles, or special places like the Loyalsock State Forest (BTW, while we're on it -- you can help us protect that place from a different threat). Poison ivy does, however, lead the world every year in causes of ER and doctor visits, as David Roberts at Grist recently found out. Ouch.

With the rash of climate science denials to deal with, who needs another rash?