Poison Ivy Loves CO2

Thanks to an article in the Washington Post Health & Science section on 31 August 2010, we now know the real reason why man's emissions of CO2 are a catastrophe.  Jacqueline Mohan, an assistant professor at the University of Georgia's Odum School of Ecology has studied the relative growth rates of tree seedlings and poison ivy in atmospheres with what she supposes have the CO2 concentrations of 1950, 2007, and a projected level for the year 2050.  The Post article by Laura Hambleton claims that tree seedlings grow 8 to 12% faster with more atmospheric CO2, but poison ivy grows 149% faster.  The article neglects to tell us between which years or concentrations of CO2 these relative growth rates were measured.  A chart of average total leaf area per poison ivy plant is presented, however.  That chart indicates about a 2.2 times increase in leaf area in 2007 relative to 1950 and a 2.7 times increase in leaf area in 2050 using the projected atmospheric CO2 concentration.  Neither number provides the stated 149% increase in growth.  What is more, most of the increase in growth from the chart has already occurred as of 2007 compared to 1950.  The leaf area for the assumed 2050 case is only about 20% greater than that of 2007.

Nonetheless, if you are inclined to prance about in the woods with little to no clothing on, this is the most awful example of increased CO2 induced catastrophe that I know about.  Even worse, the article claims that the urushiol oil that people are allergic to is becoming more virulent.  However, we should not despair too much, since Donald K. Milton, a public health physician and director of the University of Maryland Institute for Applied and Environmental Health, says children are not playing outdoors as much nowadays as they did in his youth, so increased poison ivy is not having very notable health effects. 

But poison ivy is common on the East Coast, so be careful.  Anecdotal evidence was provided that suggested that there is an observed increase in poison ivy in the woods.  It was also noted that the increased growth of poison ivy may be partially due to the woods being more broken up with more perimeter areas which get more sunlight.  Will extreme environmentalists soon use that observation as an excuse to destroy homes and businesses, so that the woods along the East Coast can be allowed to become larger with less perimeter area in which poison ivy grows better?  Please do not inform them that I have suggested this argument.