The global shift from fossil fuels to renewable energy will continue regardless of political action such as President Donald Trump's decision to withdraw the US from the Paris climate agreement or outbursts from ex-Australian prime ministers, a senior ratings analyst says.

"The tide has turned," said Michael Wilkins, the head of climate and environmental risks at Standard & Poor's Global Ratings, adding the transition meant the economic viability of assets such as coal mines and coal-fired power stations would be "vastly impaired".

Mr Wilkins' comments come as new S&P research points to deep falls in the costs of renewable energy as other groups report important shifts by corporations at home and abroad on climate risks.

Mr Wilkins said investors, including in Australia, were increasingly demanding to know how companies were monitoring financial exposure to climate change - and what they were doing about the threats.