Deutsche Presse-Agentur: New York Mayor Michael Bloomberg on Monday urged the United States, the world’s biggest polluter, to lead the fight against climate change by enacting a tax on carbon emissions blamed for global warming. Bloomberg took part in a UN General Assembly debate on climate change and laid out his own efforts to shrink carbon emissions by 30 per cent from current levels by 2030 in the city of 8 million inhabitants. His much praised programmes include converting the taxi fleet to hybrid cars, …