Contribution of Rice Production to Greenhouse Gas Emissions in Europe

About 4000 km of rice are cultivated in Europe, more than half of that grows in Italy. With emissions of methane (CH4) of 25 g CH4 m-2 y-1 and a global warming potential for methane that is more than 20 times that of CO2, it is a small but significant source of GHG emissions in Europe. Current estimates of CH4 emissions from rice cultivation from most countries are based on measurements performed under Asian conditions. In Europe, only the Italian estimate is based on country-specific emission factors, which are higher than the IPCC default values. As dry rice cultivation, according to the national submissions to the UNFCCC, occurs in Italy only, this leads to the bizarre situation that at the European scale the “implied emission factor” increases from 17.2 g CH4 m-2 y-1 for paddy rice to 32 g CH4 m-2 y-1 for drained systems. This does not include increases of emissions of nitrous oxide (N2O), which is an even more powerful greenhouse gas (GWP=310) than methane, and which tend to increase in aerated cultivation systems. This underlines the need of a more thorough investigation of the overall climate impact of European rice cultivation, including both field measurement covering sources and sinks from all greenhouse gases, and regional simulation studies. A widely applied mechanistic model is the Denitrification Decomposition model, which has already been used to estimate emissions in major rice producing countries such as China and India. We will discuss the quality of current CH4 emission estimates in view of these and own simulations.JRC.H.2-Climate chang