Amazon CEO Jeff Bezos is the world’s richest man, with an estimated net worth of $130 billion. From his heavy piggy bank, he’s decided to commit a whopping $10 billion to fighting climate change. On Monday, he announced the creation of the Bezos Earth Fund, which will be dedicated to fighting the climate emergency. The announcement came in the form of an Instagram post, in which Bezos pledged to “work alongside others both to amplify known ways and to explore new ways of fighting the devastating impact of climate change on this planet we all share.”

The move is certainly generous, but it comes after a massive pressure campaign by Amazon employees, thousands of whom signed a letter last May asking how the company would address climate change. Just before a company-wide walkout in September, Amazon announced a pledge to go carbon neutral by 2040, and vowed to deploy 100,000 electric delivery vans by 2024.

Bezos’ $10 billion donation is being met with widespread acclaim, but some are still critical of Amazon’s questionable environmental practices — particularly its partnership with oil and gas companies — and argue that the donation isn’t enough.

Amazon Employees for Climate Justice, the group that staged the walkout, said, “We applaud Jeff Bezos’ philanthropy, but one hand cannot give what the other is taking away. Will Jeff Bezos show us true leadership or will he continue to be complicit in the acceleration of the climate crisis, while supposedly trying to help?”