I really love the idea of ecosia. I heard from this search engine when I was a student, but never tried it. I'll install it in my browser and on my phone to check if it's beneficial for my searching.
Pros:
After roughly 25 searches a tree is planted, the company is transparent about how they spend their money and they are a negative CO2 company which is hard to achieve due to many companies wanting to use fossil fuels.
Cons:
Ecosia uses bing as the search engine which isn't as good as google when it comes to certain things like other than video searches.
I've used Ecosia for a long time and have been able to plant many trees and further the publics understanding of their "footprint" while living on Earth.