Change the default search engine to Ecosia.

Ecosia is an online search engine that rivals google in it usability but with a twist. It uses 80% of its revenue to plant trees all around the world. They’re helping to fight climate change by turning deserts back into fertile forests which in turn will, provide nutrition, employment, education, medical assistance and restart political and economic stability in the poorest areas of the world. 

https://info.ecosia.org/project/#projects