Agence France-Presse: The US government will propose a rule Monday requiring power plants to cut by 30 percent carbon dioxide emissions by 2030 based on 2005 levels, US media reported Sunday. The Wall Street Journal cited people briefed on the rule as saying the Environmental Protection Agency’s draft measure was due to be completed within a year. It will give leeway to US states to decide how to fulfil the reductions targets, such as through new cap-and-trade programs, deploying more renewable energy or developing…