Jeff Bezos is investing $100 million into seaweed farming as a green alternative to fossil fuels.
The Amazon founder and chief executive announced the first recipients of his $10 billion Earth Fund.
The Earth Fund, which was launched in February, is designed to combat the effects of climate change. It will issue grants to scientists, activists and other organisations to help "preserve and protect the natural world".
Mr Bezos said all grant recipients were "working on innovative, ambitious and needle-moving solutions".
Among the initial 16 eco-friendly recipients, which will receive $791m between them, are The Nature Conservancy, Natural Resources Defence Council, Environmental Defence Fund, World Resources Institute and the World Wildlife Fund for its seaweed plan.
The WWF plans to use most of the grant to scale up seaweed farming and develop its markets. Part of the funds will also be put towards protection projects in forests across the world and mangroves in Colombia, Fiji, Madagascar, and Mexico.
Earlier this year, WWF teamed up with Ocean Rainforest, a company in the Faroe Islands, to scale up its farming operations.
WWF's plan to expand seaweed farming in the North Atlantic Rim would ensure "enduring protection of 53 million hectares of critical ecosystems", it said.
Seaweed farming does not require fertiliser or pesticides. It acts as an underwater forest that absorbs carbon, nitrogen and phosphorus, making it valuable in climate change activism.
Seaweed production has grown to more than 30 million tonnes, more than doubling in the past decade. Last year, Danish scientists developed an 80kph car powered by a biofuel made from seaweed.
"By investing in the power of nature-based climate solutions, these projects aim to deliver substantial emissions reductions, conserve nature ... and improve the resilience of more than 14 million people around the world," said WWF US president and chief executive Carter Roberts.
"Our best solutions both lower global emissions and strengthen the climate resilience for people in some of the world's most vulnerable communities.
"I’ve spent the past several months learning from a group of incredibly smart people who’ve made it their life’s work to fight climate change and its impact on communities around the world," said Mr Bezos, the world’s richest man. "I’m inspired by what they’re doing, and excited to help them scale."
Mr Bezos had been criticised for a paltry philanthropic record before increasing his contributions in recent years.
His company, meanwhile, faced a revolt from employees who said Amazon had been slow to address its effect on climate change. The world's largest online retailer has since announced plans to eliminate and offset its contribution to greenhouse gases warming the planet.
About $400m of the Earth Fund grants went to well-established eco-groups but there were also new and smaller names in the list.
Among the smaller groups is the US-based Rocky Mountain Institute, awarded $8m for its carbon-free buildings campaign, and the ClimateWorks Foundation, which received $50m for its campaign to promote green policies.
The full list of grant recipients is:
- Environmental Defence Fund, $100m
- Natural Resources Defence Council, $100m
- The Nature Conservancy, $100m
- World Resources Institute, $100m
- World Wildlife Fund, $100m
- ClimateWorks Foundation, $50m
- The Climate and Clean Energy Equity Fund, $43m
- The Hive Fund for Climate and Gender Justice, $43m
- The Solutions Project, $43m
- Energy Foundation, $30m
- Salk Institute for Biological Studies, $30m
- Union of Concerned Scientists, $15m
- NDN Collective, $12m
- Dream Corps Green For All, $10m
- Rocky Mountain Institute, $10m
- Eden Reforestation Projects, $5m