A study published in Nature Communications reveals that the current drought in central-eastern Brazil is unprecedented in the last 700 years, driven primarily by anthropogenic climate change. Using speleothems from a well-ventilated cave, researchers found that the evaporative demand is no longer met by precipitation, leading to a hydrological deficit. The study shows a marked change in the hydrologic balance in central-eastern Brazil starting in the 1970s, with a severe warming trend causing increased evapotranspiration and reduced precipitation. Detection and attribution analysis indicates that this trend is mainly driven by anthropogenic forcing, not natural factors alone. The findings highlight the risk of a severe long-term drought in the subtropics of eastern South America, which is likely to be exacerbated by future greenhouse gas emissions. The study also shows that the current aridity is highly correlated with changes in surface temperature, and that the observed drying trend is not matched by any previous period in the last 720 years. The results emphasize the importance of understanding the role of human-induced warming in driving changes in the hydrologic balance and the need for effective adaptation and mitigation strategies to address future drought risks. The study used a combination of geochemical proxies, including oxygen and carbon isotopes, and trace elements, to reconstruct past hydroclimate conditions and assess the impact of climate variability on the region. The findings underscore the significance of temperature in driving hydroclimate variability and the potential for increased drought risk in the future due to anthropogenic climate change.A study published in Nature Communications reveals that the current drought in central-eastern Brazil is unprecedented in the last 700 years, driven primarily by anthropogenic climate change. Using speleothems from a well-ventilated cave, researchers found that the evaporative demand is no longer met by precipitation, leading to a hydrological deficit. The study shows a marked change in the hydrologic balance in central-eastern Brazil starting in the 1970s, with a severe warming trend causing increased evapotranspiration and reduced precipitation. Detection and attribution analysis indicates that this trend is mainly driven by anthropogenic forcing, not natural factors alone. The findings highlight the risk of a severe long-term drought in the subtropics of eastern South America, which is likely to be exacerbated by future greenhouse gas emissions. The study also shows that the current aridity is highly correlated with changes in surface temperature, and that the observed drying trend is not matched by any previous period in the last 720 years. The results emphasize the importance of understanding the role of human-induced warming in driving changes in the hydrologic balance and the need for effective adaptation and mitigation strategies to address future drought risks. The study used a combination of geochemical proxies, including oxygen and carbon isotopes, and trace elements, to reconstruct past hydroclimate conditions and assess the impact of climate variability on the region. The findings underscore the significance of temperature in driving hydroclimate variability and the potential for increased drought risk in the future due to anthropogenic climate change.