CHURCHVILLE, VA - Trees in the U.S. are growing 2-4 times as fast as their long-term norm. The Smithsonian Environmental Research Center at Edgewood MD says it is because of global warming, according to a recent press release. Don’t bet on that.
Smithsonian researchers measured a series of forest plots at different stages of growth from 5 to 225 years of age. They found that more than 90 percent of the trees grew 2-4 times faster over the past 20 years than predicted from baseline growth rates.
Helpfully, lead author Geoffrey Parker tells us that there are three main possibilities why the trees might be growing faster:
A) the official temperatures in the region have increased about 0.3 degree C over the past 20 years;
B) There’s been a small expansion of the growing season; and
C) CO2 levels have risen about 12 percent over two decades.
Dr. Parker seems to have chosen A), higher temperatures, as the correct answer. But do facts support the choice?