Rice Paddy Greenhouse Gas Emissions Have Nearly Doubled Since the 1960s

Greenhouse gas emissions from global rice paddies have nearly doubled since the 1960s, averaging approximately 1.1 billion tonnes of CO2-equivalent per year in the 2010s, making rice cultivation the largest agricultural emissions source outside livestock, according to a new study by environment and agriculture scientists. Rice demand is expected to continue rising, making emissions reduction in paddy cultivation an urgent priority.

Flooded rice paddies create anaerobic conditions ideal for methanogenic microbes that generate methane — a greenhouse gas with warming potential approximately 28 times greater than CO2 over a 100-year horizon. The study documents that total paddy emissions averaging 1.1 billion tonnes of CO2-equivalent annually in the 2010s are equivalent to the annual greenhouse gas output of 239 million cars. With more than half the world's population dependent on rice as a dietary staple, the emissions profile of paddy cultivation is a critical and politically sensitive element of agricultural climate policy.

India is one of the world's largest rice producers and consumers, with millions of smallholder farmers dependent on paddy cultivation across the Indo-Gangetic Plain, Eastern India and Coastal zones. India's paddy methane emissions are a significant component of its agricultural GHG inventory and feature prominently in international discussions about the country's agricultural mitigation potential. Alternate wetting and drying — an intermittent irrigation technique that reduces anaerobic conditions — has been shown to cut methane emissions by 30 to 70 percent with comparable yields in Indian field trials.

The study's findings increase pressure on governments to incorporate rice paddy emissions into national climate commitments and to develop financial incentives and extension support for farmers to adopt lower-emission cultivation practices. India has begun piloting alternate wetting and drying under climate-smart agriculture programmes, but scaling these practices to the tens of millions of paddy farmers nationally will require significant investment in irrigation infrastructure, extension capacity and monitoring systems. International climate finance could potentially support this transition if rice paddy mitigation is adequately recognised in carbon market and results-based payment frameworks.

Key figure — 1.1 billion tonnes CO2-equivalent per year average rice paddy emissions in the 2010s