Michael Bloomberg: Too much 'hot air' on climate change

New York City Mayor Michael Bloomberg has accused politicians in the United States of a failure of leadership when it comes to dealing with climate change.

Mr Bloomberg told the BBC that legislators at the state and national level were full of "hot air" because they preferred to put off decisive action for decades.

He was speaking ahead of a conference of mayors from 40 international cities to be held in Sao Paulo, Brazil, next week.

Mr Bloomberg said elected officials at the local level have to lead the way by improving energy efficiency, reducing pollution and preparing cities for more extreme weather.