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.
Huh? Not that I know of. They're going strong, taking on more projects around the world and are pretty transparent about what they do - they had an article about how / why one of their projects failed which i read but can't find right now.