Rice Paddy Greenhouse Gas Emissions Have Doubled Since 1960s, But Fixes Exist
Global greenhouse gas emissions from rice paddies have more than doubled over the past six decades, reaching the equivalent of roughly 1.1 billion tons of CO2 each year, according to a new study in the journal Nature Food.
Researchers led by Boston College scientists warn that methane from flooded rice fields is a major driver of near-term warming, but practical farming changes could cut emissions significantly without reducing food production.
Rice feeds more than half the world’s population, but its climate footprint is growing. Flooded paddies produce methane and nitrous oxide—two powerful greenhouse gases—as organic matter decomposes underwater. As rice farming has intensified worldwide, understanding and reducing these emissions has become a global priority.
The team combined machine learning with more than 21,000 field observations, ecosystem modeling, and global data analysis covering 1961 to 2020. They identified two main drivers behind the emissions surge: expansion of rice cultivation, especially in developing regions, and intensified crop residue incorporation, where leftover plant material is returned to flooded soils, fueling methane production.
Regionally, East Asia has seen renewed methane increases linked to heavy straw incorporation. Meanwhile, Africa has emerged as a fast-growing hotspot, with rice cultivation acreage increasing seven-fold between 1961 and 2024 to approximately 40 million acres.
Despite these troubling trends, the study highlights a clear opportunity. Improved farm management could reduce emissions by about 10 percent without compromising crop yields. Key strategies include optimizing water management to reduce methane formation, reducing excessive crop residue returned to fields, and improving nitrogen fertilizer efficiency.
The findings arrive as 159 countries have signed the Global Methane Pledge, aiming to cut methane emissions by at least 30 percent this decade. The researchers note that rice paddies represent one of the most actionable targets for near-term climate progress, given that methane drives warming much more powerfully than carbon dioxide over the first 20 years after release.