Comment by philipkglass

She's employed by Our World In Data. She is also a published author of printed books. Her substack does not have paid subscriptions enabled (or at least it did not as of last summer; see this post [1]). Our World In Data is funded by donations:

https://ourworldindata.org/funding

[1] https://hannahritchie.substack.com/p/reflections-on-substack