Over 350 employees at e-commerce giant Amazon have written statements on a Medium blog post, with the workers saying that the company needs to do more to combat climate change. The employees have attached their names and job titles to the statements, which could put their jobs at risk.

“The science on climate change is clear. It is unconscionable for Amazon to continue helping the oil and gas industry extract fossil fuels while trying to silence employees who speak out,” said Amelia Graham-McCann, a senior business analyst at the company.

“The most customer-centric thing we can do is to be a force for social and climate justice. Amazon already knows we are nothing without our customers — let’s do all we can to ensure there will still be people around to be our customers in 10, 20, 50, and 100 years,” said Amazon copy editor Brian Colella.

The online protest was organized by the Amazon Employees for Climate Justice advocacy group.

An Amazon spokesperson has said that the company “will not allow employees to publicly disparage or misrepresent the company or the hard work of their colleagues who are developing solutions to these hard problems.”

Amazon has said that it will become a net-zero carbon organization by 2040. The Amazon Employees for Climate Justice group has said that this pledge is not enough and that Amazon would need to achieve zero carbon emissions by 2030, which would be necessary to avert “catastrophic” global warming.

Amazon has also seen protests in Europe over its climate footprint, with recent demonstrations in Germany and France.