Title says it all!
https://www.ecosia.org/
Personal counter: https://ecosia.zendesk.com/hc/en-us/articles/201657341-How-does-the-personal-counter-work-
Their mission: https://info.ecosia.org/what
How to make it your default search engine in Chrome:
http://theinsiter.org/features/68200/time-to-start-using-ecosia-as-your-default-search-engine/
Edited April 9, 2018