Your website has a carbon footprint — the servers it runs on use real electricity. These hosts run on renewable energy or offset their usage, without compromising performance.
A common myth is that eco hosting means worse performance. It doesn't — GreenGeeks and A2 use the same NVMe storage and CDNs as anyone else, and Hetzner is among the best value in the world. You're choosing how the power is sourced, not accepting a slower site.