She was previously a senior counselor to the United States secretary of the interior with an emphasis was on water policy and climate change resilience.

[2] Following the election of president Donald Trump in 2016, Klein served as the deputy director of the state energy and environmental impact center at New York University School of Law.

[3][4] In this role, she supported state Attorneys General addressing clean energy, climate, and environmental initiatives of regional and national importance.

[2] On January 18, 2021, U.S. president-elect Joe Biden announced Klein as his nominee for United States Deputy Secretary of the Interior.

[3] U.S. senator Lisa Murkowski came out against Klein's nomination citing her opposition to the development of the oil and gas industry in Alaska.