US unveils sharp curbs on coal power plants

The Obama administration has released strong new rules targeting coal-burning power plants in an effort to curb global warming.

The Environmental Protection Agency's (EPA) Clean Power Plan seeks to cut carbon emissions by 30% by 2030.

The 645-page rule is a centrepiece of President Barack Obama's plans to leverage similar commitments from polluting nations like China and India.

States must submit initial compliance plans by June 2016.

"We are here to protect public health and the environment," EPA Administrator Gina McCarthy said on Monday, arguing climate change was "supercharging" risks to health, communities and the economy.

"This was the preferred path forward," she added. "Climate inaction is costing us more money in more places, more often."

The rules seek to reduce carbon emissions by 30% below 2005 levels, which the EPA says is equal to the emissions from powering more than half the homes in the US for one year.

Particle pollution, sulphur dioxide and nitrogen oxides may also be reduced by more than 25% as a co-benefit, the EPA wrote.

Critics have argued the new US rules will cause power plants to close and electricity prices to rise.