Tuesday, October 14, 2014

Plants, CO2 and Warming

A recent NAS paper demonstrates that trees and other plants absorb substantially more CO2 than estimated before. The BBC reports on this effort as follows:

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. But experts believe the new calculation is unlikely to make a difference to global warming predictions.

The paper states:

This increase represents a 16% correction, which is large enough to explain the persistent overestimation of growth rates of historical atmospheric CO2 by Earth system models. Without this correction, the CFE for global GPP is underestimated by 0.05 PgC/y/ppm. This finding implies that the contemporary terrestrial biosphere is more CO2 limited than previously thought.  

There are several observations that should be made.

1. On the negative side the Equatorial forests are often being defoliated at a rapid rate.

2. The Temperate lands are being reforested at a significant rate. New Hampshire is almost 90% forested and is more than during the Colonial daya of 300 years ago.

3. Temperate trees have a much wider region for growth, from Zone 9 through Zone 3. Thus Pinus rigida can survive from San Diego to Northern Canada. The classic Palm trees cannot.

4. 16% is not a small number especially when compounded. Just think of 1.16 to the 100th power. That is a big number.

The issue is one that states that change is a natural phenomenon and that our knowledge of that process is miniscule at this stage.