Under a comprehensive new draft supervisory guidance suggested by the Office of the Comptroller of the Currency (OCC), a leading US banking regulator, large U.S. banks would be required to include climate financial risk assessments into every part of their operations.

The OCC said it was soliciting feedback on draft principles for bank supervisors assessing that risk at lenders with over $100 billion in assets with a view to developing formal guidance.

The principles touch on everything from how climate change affects board room governance, liquidity, credit and operational risk, to the way banks project hypothetical future losses on their books and their ability to service poorer communities.

Under President Joe Biden’s administration, the OCC’s bold plan is the most important step regulators have taken to compel banks to address climate concerns. While the country’s top banks have been addressing climate risks for some time, the draft is the first time authorities would expect responsible risk management work, which could cause major issues for many banks.