For the first time researchers have found a clear correlation between deforestation and regional precipitation. A team at Leeds University has proven this using satellite and meteorological records from 2003-17 across the Amazon, Congo and SE Asia. At the largest measured scale of 200km squared (40,000 sq km), the study discovered rainfall was 0.25 percentage points lower each month for every 1 percentage point loss of forest.
So the more rainforests are cleared in tropical countries, the less rainfall will be available for local farmers. The study notes that crop yields could decline by 1.25% for each 10 percentage point loss of forest cover. This can enter into a vicious cycle, as reductions in rainfall lead to further forest loss, increased fire vulnerability and weaker carbon drawdown.
The study provides a compelling argument for tropical forest conservation in order to help maintain a cooler and wetter local climate, with benefits for nearby agriculture and people.