蜜芽传媒

US President Barack Obama has unveiled what he called "the biggest, most important step we have ever taken" in tackling climate change.

The aim of the revised Clean Power Plan is to cut greenhouse gas emissions from US power stations by nearly a third within 15 years.

The measures will place significant emphasis on wind and solar power and other renewable energy sources.

Heather Zichal, former deputy assistant to Mr Obama for Energy and Climate Change, told Today why the plan was so important to the President.