【気候変動】森林管理は単純明快な気候変動緩和策ではない

No approach to European forest management intended to help mitigate climate change is fully compliant with the goals of the Paris Climate Agreement, reports a study in this week’s Nature. Efforts would be better focused on protecting forests from climate change, rather than trying to reduce its effects, the authors argue.

The Paris Climate Agreement expects forest management to help limit the global temperature increase to less than two degrees Celsius above pre-industrial levels by the end of the twenty-first century. However, using forests to sequester atmospheric carbon dioxide might have unexpected side effects. Changes in forest management might, for example, darken the Earth’s surface, leading to the absorption of more solar radiation and higher surface temperatures. Research is needed to investigate the extent to which such effects will offset the benefits of increased carbon uptake.

Sebastiaan Luyssaert and colleagues model the outcomes of different Europe-focused forest management approaches intended to mitigate climate change. These include endeavours to maximize carbon sequestration, increase the sunlight that forests reflect back into space and reduce the near-surface temperature. The authors find that there is no single forest management approach that maximizes carbon uptake without also increasing temperatures or decreasing precipitation.

The authors find that even the most promising forest management approach — aiming to reduce the near-surface temperature - only affords modest climate benefits on the local scale. Given these results, they suggest that the primary focus of future European forest management efforts should lie not in trying to mitigate climate change, but in protecting forests from its effects.