I can't honestly say this is the most important reason to worry about global warming, but hey, if it convinces people to pay attention:
Rising levels of carbon dioxidea so-called greenhouse gas that traps heat within Earth's atmospherecan fuel booming poison ivy growth, a new study reports.
Even worse, the rash-inducing vines may become more potent.Poison ivy is no fun. Here are some great pictures of poison ivy rashes. Here's Mother Jones' (slightly less painful) cover package on global warming from last year. Hot office gossip has it that Al Gore gushed about this article on Fresh Air the other day. Do listen to Al.