Poster - #VH-92819 - Keywords: Amazon deforestation Brazil climate modeling precipitation temperature

Climatic Consequences of Unprotected Area Deforestation in the Legal Amazon

Corrie Monteverde, Ph.D. Candidate Fernando De Sales, Ph.D.
San Diego State University University of California Santa Barbara

ABSTRACT:
The deforestation activities that now predominate throughout the Legal Amazon Region are likely to continue in the future if stronger protective policies are not put in place. The expansion of cattle ranching, agricultural operations, and road networks, as well as the weakening of environmental agencies and legislation by the current federal administration have amplified deforestation rates in recent years. Unprotected forest areas cover nearly 832,000 km2 of rainforest. These areas, which exclude indigenous lands, national parks, and conservation units, are in danger since they are not protected under State or Federal jurisdiction. UnProtected Areas (UPA) cover just 15% of the Amazon, but last year they accounted for 36% of illegal deforestation in the region. This study investigates the consequences of losing these unprotected forests to the regional climate of the Brazilian Amazon region. Through a series of WRF simulations, we examine changes in surface energy balance associated with forest replacement and its impacts on wind circulation, air temperature patterns, and rainfall regimes in the region during the dry season. Our results indicate significant increase in surface albedo and wind speed over the deforested UPA associated with the reduction in vegetated ground coverage and surface roughness. These changes combined with the reduced evapotranspiration in deforested areas resulted in increased surface air temperature throughout the region, and decreased precipitation. Overall, our simulations indicated that the clearing of UPA would result in 11% decrease in evapotranspiration, 11% decrease in precipitation, and nearly 1°C increase in surface air temperature during the dry season over the Legal Amazon region. While the UPA deforestation impacts on the surface climate are limited to the cleared areas, the effects on dry-season precipitation extended to southern Brazil and neighboring countries. These results suggest that the consequences of losing its unprotected forested areas are in contradiction to a sustainable human existence in the Amazon, and may cause far-reaching changes to its regional climate.