His company is often criticised for its environmental record, but Jeff Bezos, CEO of Amazon and the world's richest man, said he was committing $10 billion to a new fund to tackle climate change.
In a post to his 1.4 million followers on Instagram on Monday, the ecommerce tycoon said the Bezos Earth Fund would "fund scientists, activists, NGOs - any effort that offers a real possibility to help preserve and protect the natural world."
"Climate change is the biggest threat to our planet," said Bezos, whose net worth is estimated to be around $130 billion.
Hundreds of Amazon employees last month signed a blog, criticising the online retail giant's climate policies and demanding it do more to tackle climate change.
Amazon has been accused of creating vast amounts of waste from the packaging it uses for doorstep deliveries, as well as for the greenhouse gas emissions from huge fleets of vehicles.
The company, which in December said its workforce had hit 750,000, has also been denounced over its carbon footprint because of the high energy consumption of its server farms for its lucrative cloud computing activities.
"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," Bezos said.
Focusing on climate change
The Amazon founder, who maintained his status as the world's richest person despite an expensive divorce last year, said his new foundation would begin issuing grants later this year.
Last September, he said Amazon would pledge to become carbon-neutral by 2040 and vowed that the company would order 100,000 electric delivery trucks.
Rather than make investments that the business guru might profit from, the fund would allocate grant money to projects, The New York Times said, quoting unnamed sources familiar with the initiative.
Bezos divulged few details on his social media post, which attracted overwhelmingly positive responses from his followers.
Bezos has often clashed with US President Donald Trump, who regularly attacks climate change activists, recently calling them "perennial prophets of doom." The fund was described as Bezos's biggest philanthropic commitment.
Fellow billionaire Bill Gates, Co-founder of Microsoft, now devotes much of his time to his charity foundation and a venture fund that makes investments aimed at helping curb emissions and reverse climate change.
(Edited by Teja Lele Desai)