Environmental activists are calling on the United States government to defend the country's trees and forests, which prove to be one of the planet's greatest shields against greenhouse gases caused by climate change.

A recent study revealed that 35 percent of U.S. forestland is made up of large, mature trees. Domestically, the majority of these trees are on federal land, yet only a quarter have formal protections.

Dominick DellaSala, a scientist with advocacy group Wild Heritage and one of the report's key authors, explained via The Hill: “It’s the large trees — the oldest trees in the forest — that are our best carbon reservoirs."

Despite research showing otherwise, logging companies claim that they play a key part in "forest health." Logging giant Weyerhaeuser describes its process as a "harmonious closed loop of carbon sequestration." The wrote in a statement about climate change that “after harvest, we replant new trees (or in some situations, we make sure the forest is regenerated naturally) to begin the cycle again."

But DellaSalla contested that mature forests, defined as those which have either never been cut or have fully recovered from past logging, retain shelter the atmosphere from a significant amount of carbon that cannot be processed by newly planted trees.

“You never really catch up to what was left in the old growth forest," he explained. "The carbon debt is transferred to the atmosphere."

DellaSala's comments came the day after Biden Administration unveiled a new plan to commit to “natural climate solutions”, at the United Nations climate change conference, COP27. The proposed roadmap aims to address the loss of native biodiversity and ecosystems, and is part of the president's allotted $25 billion infrastructure funds.

“We are grateful for Biden's roadmap from yesterday about natural climate solutions," DellaSalla said. "But we need national rulemaking to codify protection."

If these trees were to be cut down by the logging industry within the next ten years, U.S. emissions would skyrocket. DellaSala said this leaves the government with a critical choice.

He asked: “Do we protect primary forests as carbon reservoirs, or do we turn them into carbon sources — treating the atmosphere as a dumping ground for carbon dioxide?”