A group of 130 investors that control $13 trillion (£9.75tn) in assets are calling on the G20 nations to ratify the Paris Agreement.

In a letter, they said the climate deal provides a clear signal to investors that the transition to the low carbon, clean energy economy is “inevitable and already underway”.

The joint letter comes ahead of the G20 Summit in China next month.

They are also calling for a strong carbon pricing scheme, regulatory support for energy efficiency projects and clean and low carbon technologies as well as plans to phase out fossil fuels.

Europe’s Institutional Investors Group on Climate Change (IIGCC), CDP, BNP Paribas and HSBC are among those are urging to double investment in clean energy by 2020 and prepare to strengthen their nationally determined contributions.

The letter states: “Governments have a responsibility to work with the private sector to ensure that this transition happens fast enough to catalyse the significant investment required to achieve the Paris Agreement’s goals.

“Countries that join/ratify the Paris Agreement early will benefit from increased policy certainty, will be better able to attract investment in low- and zero-carbon solutions, and will accelerate the implementation of this economically and socially critical agreement.”

A spokesperson from the IIGCC said: “We hope the G20 nations will do what is requested in the letter. Especially ratify the Paris Agreement and do that this year.

“This letter is the investor community standing up alongside many other key stakeholders to make the same request. There is a lot of pressure building behind that ask.”