The Biden administration Monday officially approved the Willow Project, an $8 billon oil development project proposed by ConocoPhillips in the Alaskan arctic. While proponents of the project lauded the decision as a crucial source of job creation and revenue, some environmental groups and lawmakers derided the project as a “carbon bomb,” which severely undercuts President Joe Biden’s credentials on climate change.

The Biden administration’s final approval of the Willow Project reduced its size from the proposed five drill sites to just three. ConocoPhillips also relinquished 68,000 acres of its existing leases surrounding the sites, which the administration claims will create a “buffer” from further exploration and development activities. Alongside the approval of the project, administration also announced that up to 16 million acres of land and water in Alaska will be provided indefinite “maximum protection” from any future oil and gas leasing.

Despite the trade-offs that accompanied the Willow Project’s approval, critics have derided the Biden’s decision as a betrayal of his campaign promise to “ban new oil and gas permitting on public lands and waters,” as captured in Biden’s oft-quoted “no more drilling” primary debate pledge. Environmental groups also highlighted that ConocoPhillips has consistently described the project as a stepping-stone for future development. Even more concerning to the groups is that several of Biden’s new protections can potentially be undone by future administrations.

Governmental sources have privately noted that the Biden administration potentially faced limited options regarding the Willow Project, given the legal constraints imposed on the administration by ConocoPhillips’ leases, which have existed for decades. With its approval of the project, the Biden administration has set a course for an entirely different legal battle over environmental groups’ opposition to the project. Environmental group Earthjustice Monday said, “We’ve been fighting Willow since it was first proposed, and this isn’t the end. We will use every legal tool we have to keep this destructive project from moving forward.”

The Willow Project, initially green-lit by the Trump administration, will extract some 600 million barrels of oil from the National Petroleum Reserve-Alaska (NPR-A) on federal lands over a period of several decades. Earthjustice estimated that the Willow Project’s climate impact will amount to more than 260 million metric tons of greenhouse gases–equal to the greenhouse gas emissions “of 56 million cars driven for one year, or nearly 70 coal fired power plants operating for one year.”