• Treasury Secretary Janet Yellen called for an ambitious effort to tackle climate change.
• She called the approach a "whole-of-economy" strategy involving the public and private sectors.
• Under Biden, that approach has changed sharply to the point that some Republicans have said is an overstep on Treasury's behalf.

Treasury Secretary Janet Yellen called Wednesday for an ambitious effort across the entire U.S. economy, from pollution-emitting businesses to big financial institutions, to tackle climate change.

In a further elaboration on her office's involvement in the climate issue, Yellen cited the importance of the public and private sectors working together to cut emissions and move the world towards a greener future.

"President Biden has outlined an ambitious strategy to transition the United States to net-zero emissions and has mobilized the entire government to achieve it," Yellen said in prepared remarks to the Institute of International Finance. "At Treasury, our goal is to take this 'whole-of-government' approach and turn it into a 'whole-of-economy' approach."

Among the initiatives are a Clean Electricity Standard aimed at achieving carbon-free electricity generation by 2035. The plan also removes tax subsidies for fossil fuels and will provide grants and incentives for electric vehicles.

Yellen also said the emphasis will stretch to the financial system.

In remarks that build out on steps already taken by the Federal Reserve, which she used to chair, Yellen said work needs to be done to identify assets at risk due to potential climate disasters. From there, institutions will be called on to indicate how they are prepared to handle such risks.

She recognized that such moves are in their nascent stage and will be difficult to measure, but she said the push is necessary.

"The thinking goes that because we know so little about climate risk, let's be tentative in our actions—or even do nothing at all. This is completely wrong in my view," she said. "This is a major problem and it needs to be tackled now."

The remarks are a sharp departure for the U.S. after the Trump administration took a largely hands-off approach to the issue, withdrawing from the Paris climate accords and taking a friendlier view of fossil fuels.

Under Biden, that approach has changed sharply to the point that some Republicans have said is an overstep on Treasury's behalf.

However, Yellen said the administration is determined to tackle the issue and work with its global partners.

"We are committed to working closely with our international partners — particularly other large emitters, such as Europe, India, and China — in our shared responsibility to implement ambitious emissions reduction measures," she said.

Yellen noted that workers will be displaced by the administration's goals and said the climate initiatives will provide workforce development and the "delivery of federal resources" to communities impacted negatively by the green energy efforts.

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