but there will be challenges. agriculture, including rice production, is one of the biggest emitters of methane. solving that will be much harder. the countries who ve signed up to this deal account for about half of global methane emissions. but there are some notable absences, namely china, russia and india, who haven t come on board. to achieve this 30% global target, we will need them to step up. but having more than 100 countries on board, including some of the largest emitters, and covering the vast majority of globally traded natural gas is a very big deal. this shows methane emissions around our planet. now, for the first time, there s a target to cut the greenhouse gas. this is a significant step for the world. rebecca morelle, bbc news, glasgow. mark carney is boris johnson s finance adviser for the conference and he s been speaking to the bbc s christian fraser.