Amazon Drought: Climate Change, Fire Season, and Hydroelectric Impacts

The Amazon faces a devastating drought as rainfall that once filled rivers to record highs persisted into the northern winter, which marks the heart of the rainy season for the basin’s southern half. Low water levels in the main river and its tributaries have disrupted hydroelectric generation, affecting Brazil’s fourth largest dam and cutting drinking water supplies. Communities along the rivers have become isolated, transportation has slowed, and deaths of river dolphins and fish have increased as water systems shrink.

Alongside these harms, the drought coincides with fire season, driven by human activity such as burning to clear weeds and stubble, to clear tropical forests, and to create room for new farmland or grazing animals. In dusty, dry conditions, these fires can spread unchecked, consuming large forest areas and releasing more carbon into the atmosphere.

To understand what led to this situation, a team of scientists studied the factors at play. The drought has left the most vulnerable rural and riverbank communities short of food, markets for crops, and access to healthcare; it has also caused power outages due to interruptions in hydroelectric supply, and water rationing in some urban areas.

A boat travels through the remaining waters of Lago do Aleixo in Manaus, Brazil, in the Amazon region. EFE / Raphael Alves

Those most affected by the drought include smallholder farmers, Indigenous groups, and riverine communities across the region. These populations face high poverty, heavy reliance on farming for food, limited fresh water, and dependence on goods transported by river routes.

Strong tendency to dry out

The drought impact is worsened by longstanding land, water, and energy practices such as deforestation, loss of vegetation, fires, burnt biomass, and agricultural activities. Research points to a weakened soil moisture capacity, which reduces the land’s ability to retain water and exacerbates dryness.

Meteorological records describe the drought as an extraordinary event, with observations showing a higher frequency of drought conditions than in the past. Agricultural droughts are also rising in frequency, though the trend is more muted when climate factors are cooler.

Initial analyses show that El Niño lowered regional rainfall in a pattern similar to climate warming, but the dominant force behind the current drought is rising global temperatures. In short, climate change largely drives the severity of the drought.

Drought imagery shows another image of the crisis as the Amazon experiences concurrent stress with fire season, making clean water scarce and compounding ecological damage.

Researchers assessed how much human-caused climate change contributes to the drought by combining observational data with climate models. They looked at a six-month meteorological drought index and a six-month agricultural drought index. They found that the likelihood of meteorological drought rose by about 10 percent and agricultural drought increased nearly thirtyfold, signaling a stronger drought signal than in prior decades.

Increased water stress

Using the United States drought-scale framework, the agricultural drought today is classified as extraordinary, a level far above severe drought in a world untouched by fossil fuel combustion and deforestation. The findings warn that these events will occur more often unless fossil fuels are rapidly reduced and forests are protected. In a world warmed by 2 degrees Celsius since pre-industrial times, the probability of such events could rise dramatically, with agricultural drought occurring every 10 to 15 years and meteorological drought every year within about three decades.

Despite drought management plans already in place across the affected nations, recent droughts highlight the need to reform policies, better integrate forecasts and early warnings, strengthen contingency plans, manage water sustainably, and invest in infrastructure to withstand harsher droughts in the future. Scholars emphasize coordinated, proactive regional efforts involving farmers and other stakeholders in planning and response.

These drought dynamics appear despite uncertainty in some IPCC estimates for the region. The growing water stress caused by human-induced climate change, along with other systemic factors, remains a major threat to residents and calls for urgent steps toward improved water management and regional cooperation. The analysis advocates an interdisciplinary humanitarian response that engages local communities in planning and action.

Note: this narrative reflects a synthesis of scientific observations and climate model analyses conducted by researchers focused on the Amazon drought system.