GLASGOW — Treasury Secretary Janet Yellen called for a "wholesale transformation" of carbon intensive economies at the UN Climate Change Conference (COP26) in Glasgow on Wednesday, urging the private sector to capitalize on an opportunity to help developing nations transition to a carbon free economy.

"Rising to this challenge will require the wholesale transformation of our carbon-intensive economies," Yellen stated in prepared remarks. "It’s a global transition for which we have an estimated price tag: some have put the global figure between $100 and $150 trillion over the next three decades. At the same time, addressing climate change is the greatest economic opportunity of our time."

Yahoo Finance and Yahoo News will be reporting from COP26, which is set to begin on October 31 and last until November 12 in Glasgow, Scotland. Check out the coverage here.

Yellen specifically pledged U.S. support for Climate Investment Funds (CIF), a multilateral climate finance mechanism to help the poorest countries most affected by climate change, build out climate resilience, and shift to a future free of fossil fuels.

“Through an innovative leveraging structure, this initiative will help attract significant new private climate finance and provide $500 million per year for the Clean Technology Funds’ programming, including the new Accelerating Coal Transition investment Program,” Yellen stated.

Financing for developing countries have increasingly become a contentious point of larger climate discussions, with a $100 billion pledge by the world’s advanced economies yet to be paid out more than five years after it was initially promised.

Developing countries argue they are being unfairly tasked to pay for a climate crisis largely caused by emissions spewed by the world’s richest countries, while the poorest nations have been hit the hardest by extreme weather brought on by climate change.

On Tuesday, Special Presidential Envoy John Kerry admitted $100 billion would not be enough given that the climate crisis is intensifying and time is running out to cap global warming at 1.5 degrees Celsius, a goal climate scientists have said would avert a catastrophe.

“$100 billion doesn't do it, folks," Kerry said. "It's trillions of dollars that are needed. And the only way we will get this done is if trillions of dollars are forthcoming."

President Biden has already announced a U.S. commitment to quadruple international climate finance by 2024, to more than $11 billion. The private sector is expected to pick up the bulk of the investments, because of the sheer scale and cost of the effort needed to sunset coal powered plants and invest in renewable energy, among other measures.