The role of surface albedo changes in tropical forest loss and its climate impact

Surface albedo plays a significant role in the Earth’s climate system, dictating the amount of incoming solar radiation that is reflected by the surface. Historic land use change has been estimated to change this by 0.2 W m-2. Deforestation in the tropics now exceeds that at other latitudes and surface albedo changes associated with forest loss provide the second largest radiative impact, after CO2.

This study evaluates the surface albedo changes associated with tropical deforestation across the Amazon and South East Asia using a range of observation methods. Satellite observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) is combined with data from aircraft campaigns and in-situ observations to investigate the albedo of forest and non-forested regions.

A consistent overestimation of surface albedo changes associated with tropical deforestation is observed as a result of comparing such observations with modelling simulations within the literature, which is reflected both across the Amazon and South East Asia regions. Differences between the behaviour of surface albedo within oil palm concessions is highlighted, as is a dependency of surface albedo on the time since forest loss occurred across South East Asia.

The influence the various surface albedo observations has on the global climate is assessed by radiative forcing calculations using the Suite of Community Radiative Codes based on Edwards and Slingo (SOCRATES), where the impacts of the overestimation of albedo changes in models is shown.