Global/Regional Impacts on Present and Near-Future Climate Regimes in the Metropolitan Region of Belem, Eastern Amazon

Impact studies have contributed to a better integrated scientific understanding of the climate and environment of the Amazon, in the present, past, and future. This work aims to describe the regional impacts of human-induced landcover changes on the RAINY (January to April) and DRY (July to November) regime of the Metropolitan Region of Belem (MRB), the first frontier of Amazonian occupation. Furthermore, a dynamic downscaling (RegCM4 driven by HadGEM2-ES under the RCP8.5 scenario) was performed to investigate future global climate change impacts. A present climate (1985/2020) quantitative analysis showed that the disorderly urban enlargement in Belem and the forest suppression that led to the uncontrolled expansion of pasture/agriculture area over MRB has conditioned a local warmer climate with a significant increasing air temperature trend in both seasonal regimes. Another clear piece of evidence was the systematic intensification of the precipitation during the RAINY period. RegCM4 simulations indicate that the region will be impacted by the global climate change, such that warmer conditions in the DRY and intensified rainfall in the RAINY regime are expected to persist in the coming decades (2021/2045). Our findings for the MRB (area 3565 km(2) for a population about 2.5 million inhabitants) are relevant and should be considered in the tasks of long-term planning and elaboration of advanced strategies to mitigate future climate-related risks and urban disaster management.

Automated summary

Impact studies have improved the understanding of the climate and environment of the Amazon. The study finds that the disorderly urban expansion and deforestation in the Metropolitan Region of Belem have led to a local warmer climate and increased rainfall during the RAINY season. Simulation results also indicate that the region will continue to experience warmer conditions in the DRY season and intensified rainfall in the RAINY season in the coming decades. These findings are important for long-term planning and mitigation strategies for future climate-related risks and urban disaster management.