Ecosia uses the ad revenue from your searches to plant trees where they are needed the most. By searching with Ecosia, you’re not only reforesting our planet, but you’re also empowering the communities around our planting projects to build a better future for themselves. Give it a try!
But it still doesn't solve the issue though of being required to look at corporate ads which are designed to increase consumption in order to solve climate issues. We will never be able to advertise our way out of this.
I know it's not a perfect solution but considering the options, it's better to "sell" my attention to corporate ads in exchange of planting trees than nothing. Even then, I rarely see ads after whitelisting the site.
As far as my research goes, Ecosia seems quite reputable and I support their mission. If they're proven to be otherwise in the future, I won't have a problem to jump ship.