Brazil Identifies First Arid Zone in Northeast Due to Climate Change

Brazil's First Arid Zone Declared in Northeast

Brazil has officially identified its first arid region, a significant climate reclassification affecting a 5,700 square kilometer area in the country's semi-arid northeast. This unprecedented shift from a semi-arid to an arid climate is primarily located in the north-central region of Bahia, encompassing municipalities such as Macururé and four neighboring areas, and extending towards the border with Pernambuco near Juazeiro and Petrolina. The change, confirmed in 2023, is a direct consequence of climate change, marked by decreased rainfall and higher temperatures over a sustained period.

The Classification Process and Findings

The classification was the result of a comprehensive study conducted by the National Center for Monitoring and Early Warning of Natural Disasters (CEMADEN) and the National Institute for Space Research (INPE). Their findings were subsequently submitted to the Ministry of Environment and Climate Change. Researchers analyzed climate data, including rainfall and evapotranspiration, spanning from 1960 to 2020, with a specific focus on the 1990-2020 period for the newly arid zone. The methodology involved calculating the aridity index, a standard established by the United Nations Convention to Combat Desertification (UNCCD). A region is classified as arid when its aridity index falls below 0.2.

Climate Shift and Contributing Factors

The newly classified arid zone previously exhibited a semi-arid climate. According to Ana Martins do Amaral Cunha, a researcher at Cemaden and one of the study's authors, 'We never previously had an arid zone . It's an area in which the climate changed, from semi-arid to arid. That means it got hotter and drier.' The average annual rainfall in this region has now fallen below 400mm. This climatic transformation is largely driven by anthropogenic global warming, leading to an increase in temperatures and intensified evapotranspiration – the process where water transfers from soil and plants to the atmosphere. This creates a chronic water deficit, making it increasingly difficult for the environment to retain moisture.

Local Impacts and Broader Implications

The consequences of this aridification are already being felt by local communities. In areas like Macururé, goat farmers, who rely on the native Caatinga vegetation, are struggling as dry seasons extend and plants wither, forcing them to purchase feed for their animals. This environmental degradation contributes to a loss of soil fertility and biodiversity, and has been linked to rural exodus. The study also highlighted a broader trend: Brazil's semi-arid region expanded by an estimated 75,000 square kilometers every decade between 1960 and 2020. Furthermore, researchers predict that other areas near the Bahia-Pernambuco border could soon transition to an arid climate, potentially expanding Brazil's arid zone to nearly 15,000 square kilometers. The findings serve as a stark warning, indicating that climate change is not only intensifying existing dry conditions but also creating entirely new arid landscapes within Brazil.