If you're allergic to the vine, you don't need me to tell you this is a bad year for poison ivy. But, why is it worse this year than in other years? NPR tackled that question during yesterday's afternoon broadcast. But, this isn't the first time they've put out the same warning. They also discussed the issue in 2006 and in 2007.
You can read or listen to the broadcasts by clicking the links below:
Unlikely Fan of Global Warming: Poison Ivy -- All Things Considered, 2006
Dandelions, Poison Ivy Grow With Global Warming -- Morning Edition, 2007
Poison Ivy Growing Faster, More Virulent -- All Things Considered, 2010
The bottom line: Vines like kudzu and poison ivy love light and CO2. So, as we pump pollution into the air and cut down trees we also encourage them to flourish.
Here's more on the issue: