A new study shows that climate change may undermine forests’ ability to store carbon and keep it out of the atmosphere. They found a wide range of estimates of potential carbon gains or losses in different regions, with some regions most at risk of losing forest carbon coinciding with locations of many forest carbon offset projects.
Scientists can look at the future of forests under climate change by looking at historical and future projections, or look at datasets from long-term forest plots. They can also use machine learning to discover which climate niches tree species prefer. Or they can use complex models that include interactions between the atmosphere and the ecosystem.
By studying the combined model outputs, the researchers found that although the models forecasts differed in some ways, they did show some consistency in predictions of how different regions carbon storage may change in the future.
But the models also showed significant risks of losing carbon from forests through the threat of fire, climate stress and insect damage. With those risks, the models predicted a net carbon gain in forests across the US between 3 and 5 petagrams of carbon by the end of the 21st century. Without those climate stresses, forests could potentially store a net 9.4 petagrams of carbon.
“For carbon offsets to be effective,” said William Anderegg, study senior author, “they have to store carbon for a pretty long amount of time – multiple decades to centuries. So if fire’s burning them down or insects are wiping out different areas, it could vastly undermine their effectiveness as climate change solutions.”
“Working to tackle climate change as quickly as possible and move to a lower carbon future massively decreases the risks that forests are likely to face in the 21st century,” Anderegg said, “and increases the potential benefits that we might get from forests.”
https://scitechdaily.com/climate-change-vs-forests-the-carbon-storage-showdown/