Amazon rainforest generates 300 liters of rainfall per square meter each year, new study reveals

For decades, scientists have understood that rainfall patterns depend on geography, ocean currents, and atmospheric circulation. But groundbreaking new research published in Communications Earth & Environment reveals that tropical forests play a far more active role in creating the rain that sustains entire regions—essentially manufacturing their own weather systems.

The comprehensive study used satellite data and climate models to quantify something long suspected but never precisely measured: how much rainfall tropical forests actually generate. The results are striking. Each square meter of tropical forest produces approximately 240 liters of rain annually across the surrounding landscape, with Amazon forests generating even more—roughly 300 liters per square meter each year.

This rain-making process begins with evapotranspiration, where trees absorb water through their roots and release it as vapor through their leaves. This moisture rises into the atmosphere, forms clouds, and eventually falls as precipitation downwind—sometimes hundreds of miles away. The Amazon essentially acts as a massive atmospheric river, recycling moisture from the Atlantic Ocean deep into the continental interior.

The implications for deforestation are sobering. The research shows that each percentage point of tropical forest loss reduces regional rainfall by 2.4 millimeters annually, with even larger impacts in the Amazon. Satellite observations suggest the effects may be stronger than current climate models predict, meaning we may be underestimating how forest destruction disrupts regional water cycles. As the study demonstrates, protecting tropical forests isn’t just about preserving biodiversity—it’s about maintaining the rainfall that millions of people and countless ecosystems depend on for survival.