More than 200 forest ecologists and top climate scientists, including Jim Hansen and Michael Mann, have written the Biden administration urging it to quickly move forward on the president’s commitment to protect old-growth and mature forests on federal lands. The scientists made an urgent plea for an immediate moratorium on logging federal forests with trees 100 years old or older, many of which remain vulnerable to logging and dozens of timber sales nationally. They also asked for the establishment of substantive federal management standards to protect those forests. Federally owned old-growth and mature forests play an outsized role in storing carbon, offering a vital hedge against escalating climate change. At stake are 112.8 million acres of old-growth and mature forest on federal lands, according to a 2023 U.S. Forest Service inventory. Less than a quarter of those forests are currently protected against logging.