Theres not much to smile about in the run up to Copenhagen. However, I snapped up this piece of good news in August but haven’t had the time to post it. Its well worth a read. Basically, draining the water out of rice paddies during the growing season has led to dramatic reductions in methane emissions from Chinese rice-growing sector. Studies conducted by scientists from China and the United States estimate that methane emissions from rice paddies have fallen by a staggering 70% since 1980.

Farmers normally flood rice fields throughout the growing season, meaning that methane is produced by microbes underwater as they help to decay any flooded organic matter.

By studying experimental rice plots and real farmland, Chris Butenhoff and Aslam Khalil, physicists from Portland State University in Portland, Oregon, together with Xiong Zhenqin, an ecologist at Nanjing Agricultural University in China’s Jiangsu province, and their colleagues set out to identify the different factors that affect this process.

The team found that draining paddy fields in the middle of the rice-growing season — a practice that most Chinese farmers have adopted since the 1980s because it increases rice yields and saves water — stopped most of the methane release from the field. The team presented their results on 13 August at a meeting on climate science convened at a Beijing hotel by the US Department of Energy and China’s Ministry of Science and Technology.

Earlier this year, another team of scientists reported that global methane emissions from rice paddies could be cut by 30% if fields are drained at least once during the growing season. This is a great example of changes in farming practices that not only result in substantial improvements in local and regional yields, but could also have a significant effect in reducing global greenhouse gas emissions.