Abstract:
Large-scale land-use change, such as Amazon deforestation, can have a significant local effect on the climate and has the potential to impact the global climate system. Previous modeling studies have shown non-local responses due to Amazon deforestation. However, a common flaw in these studies is using prescribed ocean conditions, which can dampen the global response. This study uses a set of fully coupled modeling simulations to determine the responses and sensitivities to Amazon deforestation, both locally and globally. In addition, a set of realistic tropical crop vegetation types are developed for the Community Land Model version 4.5. The local increase in surface temperature and decrease in precipitation from this study are consistent with previous modeling studies. After deforestation, it was determined that stronger regions of land-atmospheric coupling are found in the formerly densely forested regions, while areas that receive irrigation become less coupled. This study highlights large-scale changes to the zonal and meridional circulation that are found to have impacts in remote regions throughout the tropics. Lastly, using a set of partial deforestation simulations, areas of non-linear responses to deforestation are found. A metric to quantify the degree of non-linearity over the spatial domain was developed; Amazon deforestation is found to have a tipping point effect for the climate system with less than half of the impacts within the spatial domain of influence being provided by 50% deforestation.
