Tropical forests generate vast amounts of rainfall, essential for agriculture and water security, with a new University of Leeds study assigning a staggering monetary value to this overlooked service.
Researchers found each hectare produces 2.4 million litres of rain annually, equivalent to an Olympic swimming pool, bolstering calls for stronger protection as climate pressures mount.
Published in Communications Earth & Environment, the study “Quantifying tropical forest rainfall generation” integrates satellite data with advanced climate models to quantify forest-driven precipitation via evapotranspiration.
DOES INDIA HAVE TROPICAL FORESTS?
India is home to tropical forests, especially in regions that experience heavy rainfall, warm temperatures, and high humidity year-round. These forests are largely classified as tropical evergreen and tropical moist deciduous ecosystems, found in a few major geographic zones across the country.
The Western Ghats, stretching along India’s western coastline, contain some of the nation’s most extensive tropical evergreen forests. With abundant rainfall, these forests stay lush and green throughout the year.
They rank among the most biodiverse ecosystems on Earth, supporting wildlife such as the lion-tailed macaque, hornbills, and thousands of plant species. Protected regions like Silent Valley National Park play an important role in conserving these rainforest-like environments.
HOW DO TROPICAL FORESTS GENERATE MONEY?
Across the tropics, each square metre of forest yields about 240 litres of rainfall yearly, surging to 300 litres in the Brazilian Amazon.
For the Amazon alone, this service is worth roughly $20 billion annually to regional agriculture, dwarfing current financial incentives for conservation.
Lead author Dr Jess Baker from Leeds’ School of Earth, Environment and Sustainability emphasised: “This is the most comprehensive evidence to date of tropical forests’ rainfall provision.”
The analysis reveals deforestation’s toll: loss of 80 million hectares in the Amazon may have slashed rainfall benefits by nearly $5bn per year, disrupting food production, hydropower, and water supplies.
Key crops shows forests’ indispensable role. Cotton requires 607 litres of moisture per square metre, matched by two square metres of intact forest. Soybeans demand 501 litres, equivalent to 1.7 square metres of forest.
Brazil, with 85% rain-fed agriculture, faces acute risks; delayed wet seasons in deforested zones have already curbed soy and maize yields.
The study argues that major croplands need moisture from forest areas exceeding their own footprint, highlighting a critical interdependence often ignored in policy.
Beyond farming, forest loss endangers drinking water, river navigation, hydropower, and even the remaining forests’ carbon storage. Despite global pledges to end deforestation by 2030, losses persist across the tropics.
Co-author Dr Callum Smith noted: “Tropical forests make it rain, supplying water essential for agriculture. Recognising this could ease tensions between farming and conservation.”
Researchers urge integrating rainfall valuation into economic and legal frameworks to unlock investment and fortify protection efforts.
As Brazil’s economy exemplifies vulnerability, the findings amplify urgency: safeguarding forests isn’t just environmental—it’s an economic imperative for sustainable prosperity.
