Ecosia is a search engine that aggregates search results from multiple other search engines. The ad revenue from our searches funds the planting of trees worldwide. With over 200 million trees planted so far, Ecosia have learned to be fully transparent about their projects, and financials which are available right on that website. Set it as your default search engine, and start planting trees. They also recently released a Chromium based browser if that’s your thing - TechCrunch article for reference.
OK posting here to address the skepticism, which I completely understand and have been through. Here are some articles that came up when simply searching “is ecosia legit”: Utopia “Ecosia is certainly legit. It’s above board”, Snopes “Ecosia makes money through advertisements on its search engine. While a portion of that money is used to fund the operational costs of the business, about 80% of its surplus revenue is donated to environmental organizations and tree-planting projects around the world.”, GoodGoodGood, TechJunkie and there’s plenty more