AAP: Greens leader Bob Brown says his party will lead the national parliamentary debate on climate change, pushing for tougher cuts in emissions and massive funding for public transport. Addressing the Australian Greens national Council meeting in Hobart, Senator Brown said Prime Minister Kevin Rudd will have failed to show mature leadership if Labor sets weak targets for emissions cuts or if it delayed implementation of an emissions trading scheme to 2012. He said the Greens wanted …