Chief Executive Officer Jeff Bezos will commit $10 billion to fund scientists, activists, nonprofits and other groups fighting to protect the environment and counter the effects of climate change, he said on Monday.

Cutting emissions will be challenging for Amazon. The e-commerce company delivers 10 billion items a year, has a massive transportation and data centre footprint, and has faced criticism from within its own workforce.

Bezos, the world’s richest man, is among a growing list of billionaires to dedicate substantial funds to battle the impact of global warming.

“Climate change is the biggest threat to our planet,” Bezos said in an Instagram post.

“I want 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 Bezos Earth Fund will begin issuing grants this summer as part of the initiative.

“It’s going to take collective action from big companies, small companies, nation-states, global organizations, and individuals,” Bezos said.

Counteracting climate change has become a popular cause for U.S. billionaires in recent years, with Microsoft’s Bill Gates, Michael Bloomberg and hedge fund manager Tom Steyer counted among the world’s wealthiest environmental philanthropists. ⁣⁣⁣ Last year, Bezos pledged to make online retailer Amazon net carbon neutral by 2040 – the first major corporation to announce such a goal – and to buy 100,000 electric delivery vehicles from U.S. vehicle design and manufacturing startup Rivian Automotive LLC.

Bezos also said at the time that Amazon would meet the goals of the Paris climate accord 10 years ahead of the accord’s schedule and invest $100 million to restore forests and wetlands.

Amazon has faced protests by environmental activists and pressure from its employees to take action on climate change.

Amazon workers were among hundreds of employees of big technology companies to join climate-change marches in San Francisco and Seattle late last year, saying their employers had been too slow to tackle global warming and needed to take more drastic action.

Amazon Employees for Climate Justice, an activist workers group, welcomed the Bezos Earth Fund announcement but said it did not make up for the company’s consumption of fossil fuels and other activities that contribute to climate change.

“We applaud Jeff Bezos’ philanthropy, but one hand cannot give what the other is taking away,” the group said on Twitter.