IPCC AR6报告解读：陆地和淡水生态系统及其服务变化

IPCC第六次评估报告（AR6）第二工作组（WGII）报告的第二章表明,气候变化对陆地和淡水生态系统影响的范围和程度较前期评估结果更为严峻。人为气候变化导致生态系统结构、功能和恢复力恶化,生物群落转移,疾病的传播范围和发病率增加,野火燃烧面积增加和持续时间延长,局部地区物种灭绝,极端天气的频率和强度增加。未来气温升高2~4℃情景下,陆地和淡水生态系统中高灭绝风险物种占比为10%~13%,野火燃烧面积增加35%~40%,森林地区50%以上树木面临死亡风险,15%~35%的生态系统结构发生转变,碳损失持续增加,气温的升高将进一步加剧这些风险造成的严重且不可逆的影响。通过生态系统保护和恢复等人为适应和减缓措施,可以在一定程度的气候变化范围内保护生态系统的生物多样性并增强生态系统服务在气候变化下的恢复力。加剧的气候变化将阻碍适应措施的制定和实施,为保证措施的有效性需要考虑气候变化的长期影响并加快适应措施的部署。

Interpretation of IPCC AR6: terrestrial and freshwater ecosystems and their services

Chapter 2 of Working Group II's IPCC Sixth Assessment Report suggests that prior reports underestimated impacts of climate change on terrestrial and freshwater ecosystems due to complex biological responses to climate system. Anthropogenic climate change has led to deterioration of ecosystem structure, function and resilience, biome shifts and structural changes within ecosystem, increased wildlife diseases, increased area burned by wildfire, localized species extinctions and more extreme events. Under the scenario of temperature rise of 2-4℃ in the future, the percentage of species at high risk of extinction will be 10% to 13%, the wildfire burned area will increase by 35% to 40%, risks of tree mortality will exceed 50% in forest area, biome shifts on 15% to 35% and carbon loss continues to increase. The continuous increase of global temperature will aggravate the severe and irreversible impacts of these risks. The resilience of biodiversity and ecosystem services to climate change can be increased by human adaptation actions and mitigation measures including ecosystem protection and restoration. Aggravated climate change hinders the development and implementation of ecosystem-based adaptation. The long-term impacts of climate change need to be considered and the deployment of adaptation should be accelerated to ensure their effectiveness.