The Trump Administration wants to allow logging in previously off-limit areas of Alaska's Tongass National Forest, the U.S. Forest Service announced Tuesday, a move that could turn one of the nation's largest carbon sinks into a source of new climate-changing emissions.

The old-growth temperate rainforest contains trees that are centuries old and play a crucial role in storing carbon. In a state that is synonymous with oil production, the Tongass National Forest represents the potential for natural solutions to help combat the climate crisis.

A 9.4-million acre swath of the Tongass has been protected under a Clinton-era requirement called the Roadless Rule, which safeguarded 58 million acres of undeveloped national forest lands from roadbuilding, logging and mineral leasing. But the Tongass has long been an area of hot dispute.

The Forest Service is now moving to exempt the rainforest — and make tens of thousands of old-growth acres available to logging.

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"The Tongass National Forest stores more carbon removed from the atmosphere than any other national forest in the country," said Josh Hicks, campaign manager at The Wilderness Society. "By seeking to weaken the Roadless Rule's protections, the Forest Service is prioritizing one forest use — harmful logging— over mitigating climate change, protecting wildlife habitat, and offering unmatched sight-seeing and recreation opportunities found only in southeast Alaska."

In August, Trump ordered Agriculture Secretary Sonny Perdue to exclude the area from the Roadless Rule. The draft environmental impact statement — expected later this week — will aim to do just that, according to a press release issued on Tuesday that describes the administration's plan. If enacted, it would allow roads to be built throughout the now-protected area, and it would convert 165,000 old-growth acres and 20,000 young-growth acres previously identified as unsuitable timber lands to suitable timber lands.

The Alaskan delegation had been pushing for a relaxation of the rule, arguing that the prohibition on developing that area negatively affects the state's ability to harvest timber, develop minerals and expand energy projects. "I thank President Trump, Secretary Perdue, and the team at the Forest Service for their hard work to reach this point — and for their continued efforts to restore reasonable access to the Tongass National Forest," said Senator Lisa Murkowski (R-Alaska).

Protections for roughly 5.7 million acres of the forest designated as wilderness lands will remain intact.

A Major Carbon Sink

From a climate perspective, the plan could have global implications.

"The longer those trees are out there, the longer they have been absorbing carbon from the atmosphere and holding onto it — sequestration. That results in excess carbon that the plants store over time," said Dominick DellaSala, the chief scientist at the Geos Institute in Oregon, a nonprofit that studies climate solutions. "In the case of an old-growth forest, some of those trees have been out there for 400, 500 years, absorbing and storing carbon and helping to keep the planet cool."

The ancient trees in the Tongass store at least 8 percent of the total carbon absorbed by all national forests in the lower 48 states, DellaSala said. "When we clear-cut a forest, most of the carbon is put back into the atmosphere," he said.

A report released by the United Nations one year ago found that in order to keep global warming below 1.5°C, the world will need to find ways to remove carbon from the atmosphere. Part of that requires the development and scaling of new technologies. But natural solutions must play a role, too, the report found.

Trump's action is "going to put more carbon dioxide into the atmosphere at a time when we need to be drastically reducing emissions and getting off of fossil fuels and keeping carbon stores in places like the Tongass," DellaSala said.

History on Their Side

The Tongass National Forest represents the latest step in the Trump administration's efforts to open up public lands to industry, which have led to clashes with environmental groups.

Those fights are well underway elsewhere in Alaska. The administration is working to allow drilling in the Coastal Plain of the Arctic National Wildlife Refuge and in new areas of the National Petroleum Reserve. It is trying to ease protections in salmon streams and to allow open pit copper and gold mining at Pebble Mine, on the shores of Bristol Bay.

In the Tongass, as with the other areas in Alaska, attorneys representing environmental groups are closely watching the Trump administration's moves to see if there are opportunities to sue.

"The agency will have to issue a final impact statement, which is expected next year," said Eric Jorgensen, Earthjustice managing attorney in Juneau."Then at that point, there could be challenges to the rule so we and others will be giving it the closest scrutiny. We don't think the agency will be able to marshal the arguments to justify the exemption."

Environmental groups will have history on their side, Jorgensen said.

President George W. Bush tried unsuccessfully to overturn the Roadless Rule's application to the Tongass. "We filed a lawsuit with others challenging that exemption and the district court in Alaska, and ultimately the 9th circuit court of appeals rejected the decision, holding that the agency has not justified its change in position," Jorgensen said.