Amazon employees are voicing serious concerns about the company’s AI rollout.

Over 1,000 Amazon staff members anonymously signed an open letter addressed to Amazon CEO Andy Jassy and the senior leadership team last week. In the letter, employees warned that the company’s current AI strategy threatens jobs and the environment.

The signatories range from Whole Foods workers to IT staff and represent a small percentage of Amazon’s 1.53 million total employees, according to its third-quarter earnings report. More than 3,600 workers outside of Amazon also signed the letter.

Related: Amazon CEO Reveals the Real Reason Behind the Company’s 14,000 Job Cuts

In the open letter, the signatories claim that Amazon is “casting aside its climate goals to build AI” and point to the company’s annual emissions growing by 35% since 2019, despite a commitment to achieve net zero carbon emissions by 2040.

Amazon strongly rejected the claims and defended its climate and AI investments. Amazon spokesperson Brad Glasser told Fortune in a statement on Tuesday that the letter’s claim that the company has put aside its climate goals is “categorically false and ignores the facts.”

“Amazon is already committed to powering our operations even more sustainably and investing in carbon-free energy,” Glasser said in a statement. “This includes supporting two advanced nuclear energy agreements and investing in more than 600 renewable energy projects worldwide.”

The letter also highlights Jassy’s remarks earlier this year that AI would cause Amazon’s workforce to shrink “in the next few years.” Jassy encouraged Amazon employees to use AI and participate in training on the technology.

The employees see Jassy’s comments as a statement that the company is “forcing” them to use AI while “investing in a future where it’s easier to discard us.” Workers are experiencing higher expectations for output and shorter timelines to complete projects, the letter states.

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Amazon laid off 14,000 employees in October, one of the largest job cuts in its history, as it made significant investments in AI infrastructure.

In a third-quarter earnings call, Amazon CFO Brian Olsavsky said that the company had spent $89.9 billion so far this year on its cloud computing business, Amazon Web Services, as well as AI infrastructure like data centers.

The open letter demands employee input in AI adoption. The signatories want Amazon to create working groups of non-managers across the company who will help decide how AI-related layoffs or hiring freezes are implemented. Employees would have a formal role in reviewing AI use across the company.

“The Amazon employees signing this letter believe in building a better world — not in building bunkers to fall back to,” the letter reads. “We want the promised gains from AI to give everyone more freedom.”