Assessing the non-local Climate impacts of Tropical deforestation (ACT)

整个热带地区正在迅速砍伐森林，这对当地和区域气候产生了重大影响，包括气温升高和降水量减少。虽然现在有强有力的证据表明砍伐森林对当地气候的影响，但人们对森林砍伐如何改变距离森林砍伐地点数十至数百公里范围内的气候的了解非常有限。这些非本地气候影响很难评估，而且限制很少，但对生活在热带森林地区的数百万人的生活有重要影响。我们对卫星数据的分析表明，在巴西亚马逊地区，既有当地森林砍伐，也有区域森林砍伐的地区，其地表变暖程度是只有当地森林丧失的地区的四倍，这表明非当地的影响是巨大的。我们将使用卫星遥感、机器学习和区域气候模型的新组合，首次详细评估热带森林砍伐对气候的非局部影响。我们将应用机器学习方法，在温度和降水的卫星记录中隔离森林丧失对当地和非当地气候的影响。我们将使用嵌入水蒸气跟踪的区域气候模型来评估森林砍伐如何改变水通量、区域水收支和气候。我们将量化通过我们的热带森林利益攸关方网络确定的与政策相关的情景和干预措施对区域气候的影响。这项工作将改变我们对森林砍伐如何改变区域气候的理解，并将确保新的结果支持热带地区基于证据的可持续土地利用。

Rapid deforestation is occurring across the tropics with substantial impacts on local and regional climate including increased temperature and reduced precipitation. Whilst there is now strong evidence of the local climate impacts of deforestation, there is very limited understanding of how deforestation alters the climate at distances of tens to hundreds of km from the location of forest loss. These non-local climate impacts are challenging to assess and are poorly constrained, but have important impacts on the lives of millions of people living across tropical forest regions. Our analysis of satellite data has shown that regions of the Brazilian Amazon with both local and regional deforestation have experienced four times greater land-surface warming than regions with only local forest loss, suggesting that non-local impacts are substantial. We will use a novel combination of satellite remote sensing, machine learning and regional climate models to make the first detailed assessment of the non-local impacts of tropical deforestation on climate. We will apply machine learning methods to isolate the local and non-local climate impacts of forest loss in satellite records of temperature and precipitation. We will use a regional climate model with embedded water vapour tracking to assess how deforestation alters water fluxes, regional water budgets and climate. We will quantify the regional climate impacts of policy relevant scenarios and interventions identified through our network of tropical forest stakeholders. This work will transform our understanding of how deforestation alters regional climate and will ensure new results support evidence-based sustainable land use in the tropics.