Yahoo TV

China's President Xi Jinping has declared that his country stop building new energy projects abroad that use coal, a move that was immediately welcomed by the United States and the head of the United Nations' climate change conference.

The announcement at the UN General Assembly could affect 44 coal plants earmarked for Chinese state financing, totalling $50 billion, according to Global Energy Monitor, a U.S. think tank.

That has the potential to reduce future carbon dioxide emissions by 200 million tonnes a year, the think tank told Reuters.

Environmental groups said it would force big coal financiers like the Bank of China, linked with 10 gigawatts of overseas coal power capacity, to draw up a timetable to withdraw from the sector.

Beijing is the largest source of financing for coal power plants globally and Xi's announcement will have a far-reaching impact on coal power expansion plans in countries like Bangladesh, Indonesia, Vietnam and South Africa.

However, Xi's carefully worded statement revealed few details and left room for existing projects to continue.

There are already more than 20 Chinese financed coal-fired power units under construction in the world, according to data from the Boston University Global Development Policy Center.

Another 17 are in the planning stage.

The new commitment also doesn't address China's plans to expand its own coal-fired power plants.

According to a report published by a European think tank, China's domestic program accounts for more than half of all the coal-powered plants under construction through the world.