Nov 25, 2019

The impact of rising CO2 and acclimation on the response of US forests to global warming

John S. Sperry, Martin D. Venturas, Henry N. Todd, Anna T. Trugman, William R. L. Anderegg, Yujie Wang, Xiaonan Tai
Proceedings of the National Academy of Sciences

Our present-day models don't do physiology or acclimation. They matter absolutely enormously to the future of forests. We came up with ways to incorporate those.

William Anderegg, study co-author, University of Utah

  • States that the benefit of climate change for forests is that higher atmospheric CO2 allows trees to use less water and photosynthesize more
  • States that the problem of climate change is that warmer temperatures make trees use more water and photosynthesize less
  • Predicts the outcome of these opposing influences using a physiologically realistic model which accounted for the potential adjustment in forest leaf area and related traits to future conditions
  • Finds that if forests fail to adjust, only 55% of climate projections predict a CO2 increase large enough to prevent warming from causing significant drought and mortality
  • Finds that if forests can adjust, the percentage of favorable outcomes rises to 71%; however, uncertainty remains in whether trees can adjust rapidly and in the scatter among climate projections