America's climate change chief says he's not surprised Europe's leaders can't agree on who will pay for cuts in greenhouse gases because their targets are too high. The EU aspires to cut gases by 20% by 2020 but James Connaughton told BBC news that this was simply unrealistic. We're also learning today that Mexico has announced plans to cut its greenhouse gas emissions by fifty percent before 2050. The Mexican environment minister, Juan Rafael Elvira, said he hoped the plan would inspire other developing countries to take strong actions against emissions. BBC environment correspondent Matt McGrath joins us now from Poznan, Poland.