摘要：Policies for climate mitigation on land rarely acknowledge biophysical factors, such as
reflectivity, evaporation, and surface roughness. Yet such factors can alter temperatures
much more than carbon sequestration does, and often in a conflicting way. We outline a
framework for examining biophysical factors in mitigation policies and provide some
best-practice recommendations based on that framework. Tropical projects—avoided
deforestation, forest restoration, and afforestation—provide the greatest climate value,
because carbon storage and biophysics align to cool the Earth. In contrast, the climate
benefits of carbon storage are often counteracted in boreal and other snow-covered regions,
where darker trees trap more heat than snow does. Managers can increase the
climate benefit of some forest projects by using more reflective and deciduous
species and through urban forestry projects that reduce energy use. Ignoring
biophysical interactions could result in millions of dollars being invested in some
mitigation projects that provide little climate benefit or, worse, are counter-productive.
