Britain's coalition government Tuesday set out ambitious plans aimed at reducing carbon emissions by 50 per cent on 1990 levels by 2025, according to dpa. The plans were announced in parliament by Energy Secretary Chris Huhne, from the Liberal Democrats, who adopted proposals made by the expert committee on climate change, an official government advisory body. The goals are contained in the government's fourth "carbon budget", which runs from 2023 to 2027. They are part of of Britain's long-term efforts to cut emissions by 60 per cent by 2030, and by 80 per cent by 2050. The proposals include an opt-out clause in the event that Britain's European Union (EU) partners fail to agree on similar aims. They will be reviewed in 2014. The announcement makes Britain the first country in the world to have declared a legally-binding target on greenhouse gas emissions beyond 2020, Huhne said. The set of five-yearly carbon budgets maps out the stages Britain should go through to reach its 2050 goal.