“Redwood forests near the California-Oregon border have seen the largest surge in wood production, with growth rates since the 1970s up to 45 percent faster now than at any time in the past 200 years.” For the second day in a row I’m looking at the San Jose Mercury News as my source for a story that seems like untrammeled good news.
“We’re not seeing any evidence of declining growth rates,” said Steve Sillett, a forestry professor at Humboldt State (where I briefly studied anthropology and journalism) and nationally known redwoods expert. “In fact, a lot of the sites are exhibiting increasing rates of growth over the last 100 years.”
As Matt Ridley reported two years ago, this was predicted by Charles Keeling, known for the eponymous Keeling Curve. It isn’t just the redwood forests. Ridley wrote, “Between 1982 and 2011, 20.5% of the world’s vegetated area got greener, while just 3% grew browner; the rest showed no change.
What explains this trend? Man-made nitrogen fertilizer causes crops to grow faster, but it is having little effect on forests. There are essentially two possibilities: climate and carbon dioxide itself. Warmer, wetter weather should cause more vegetation to grow. But even without warming, an increase in carbon dioxide should itself accelerate growth rates of plants. CO2 is a scarce resource that plants have trouble scavenging from the air, and plants grow faster with higher levels of CO2 to inhale.”
Models were unable to capture the magnitude of this effect, according to the BBC. “Global climate models have underestimated the amount of CO2 being absorbed by plants, according to new research. Scientists say that between 1901 and 2010, living things absorbed 16% more of the gas than previously thought. The authors say it explains why models consistently overestimated the growth rate of carbon in the atmosphere.”
In perhaps what is the understatement of the century, the BBC story has a quote from Dr Lianhong Gu at Oak Ridge National Laboratory in the US: “”There is a time lag between scientists who study fundamental processes and modellers who model those processes in a large scale model. It takes time for the the two groups to understand each other.”