Resources giant Rio Tinto has joined US utilities to urge Washington to spend $20 billion (£10.09 billion) on a technology they say has the best chance for cutting pollution linked to global warming.

The US Senate today launches a debate on climate change but politicians have been warned that the coal companies will not foot the bill for a solution alone.

Instead, energy firms including Rio are lobbying Congress to help create devices to trap carbon dioxide from coal-fired power plants and bury the gas in underground caverns. They say the projects will not get off the ground unless the US supports the scheme.

Rio says the industry has already spent "tens of millions of dollars", on development but a definitive solution to the problem is too costly for companies to shoulder alone.

"We can't do it without government support for the early projects," said Rio Tinto chief executive officer for energy, Preston Chiaro, who is also chairman of the London-based World Coal Institute.