Funds are set to spur creation of four U.S. hubs to remove carbon dioxide directly from ambient air, but some advocates question their efficiency.

Gov. Gretchen Whitmer (D) signed two executive orders requiring the state to reduce carbon dioxide emissions by 28% over 1990 levels by 2025 and be carbon neutral by 2050. If she loses reelection in 2022, a future governor could rescind the mandates,

A new National Academies of Science, Engineering and Medicine report could add momentum to negative emissions technologies, which can remove carbon from the air.