Research has revealed that local deforestation, alongside global climate change, is significantly impacting the Amazon rainforest’s climate. A study published in Nature Communications shows that deforestation has led to a nearly 8 percent decrease in precipitation during dry seasons since 1985. This decline amounts to approximately 21 millimeters less rain, which could have dire consequences for the region’s ecosystem.
The Amazon rainforest, the largest on Earth, plays a crucial role in the global climate system. Over the past decades, the region has experienced notable changes in its water, carbon, and energy cycles, which directly affect precipitation levels. Researchers from Brazil and the Max Planck Institute for Chemistry in Germany conducted a detailed analysis to quantitatively assess how each factor contributes to these climatic shifts.
Deforestation’s Impact on Rainfall and Temperature
According to Luiz Machado, a climate researcher at the University of São Paulo, local deforestation is responsible for approximately 75 percent of the decline in rainfall. He states, “Even small changes in rainfall during the dry season could therefore have a disproportionate impact on vegetation health.” In dry months, rainfall drops to only 26 percent of the average annual precipitation, totaling 281 millimeters compared to 1,097 millimeters during the rainy season.
The study also explored the relationship between deforestation and rising temperatures. It found that while deforestation contributes about 16 percent to the 2 °C increase in temperature, the majority, around 84 percent, is linked to global climate change. Notably, the research indicates that the Amazon’s climate does not respond uniformly to deforestation. The most severe effects occur early in the deforestation process, particularly when 10 to 40 percent of the forest is lost.
Future Projections and Urgency for Action
The researchers analyzed data from 29 regions in the Brazilian Amazon collected over the past 35 years using satellite imagery and atmospheric measurements. Their findings reveal that over 99 percent of the increase in greenhouse gases, such as methane and carbon dioxide, is due to global climate change, with deforestation accounting for a mere 0.3 percent of the CO2 increase.
Looking ahead, the study projects that if deforestation continues at its current rate, the Amazon could see an additional temperature rise of about 0.6 °Celsius and a further decrease in precipitation of approximately seven millimeters during the dry season by 2035. Christopher Pöhlker from the Max Planck Institute states, “This will certainly put additional stress on the forest.”
The findings underscore the urgent need to halt further deforestation to protect the Amazon’s climatic resilience. The region is undergoing a critical transformation, exacerbated by extreme weather events like the severe drought experienced in 2023. The complex interplay between climate change and deforestation complicates efforts to determine a specific threshold of deforestation that could lead to the ecosystem’s collapse.
As the world grapples with climate change, the preservation of the Amazon rainforest remains a vital concern, not only for the region but for global ecological stability.
