As you can read in DreamHost’s web, one of the most important web hosting,  they  are trying very hard to be more respectful with the nature:

DreamHost is carbon neutral. We’ve calculated the impact of everything that DreamHost uses and leaves behind in the course of our daily work. All of the resources that we use in order to host webpages - paper in the office, electricity for our servers, even the gas in our cars that bring us to the office - leaves behind some kind of soul-sucking residue in the world.

When we learned that running DreamHost generated as much carbon dioxide as 545 average-size homes we realized we had to do something to neutralize our emissions.

With a bit of research we found the most effective approach begins with resource conservation: turning off the lights, reducing travel, printing on both sides of the page. Efforts are being ramped up here daily to do what we do with less. The next step is to use clean, renewable energy in our hosting servers in the datacenters. Without the option to put up solar panels or connect with a green power utility for us this means purchasing Renewable Energy Credits. Finally, to neutralize those unavoidable emissions we’ve invested in Emission Reduction Credits (a.k.a. “offsets”) which guarantee our remaining impact is effectively erased. A third-party-certification? Never fear. The credits we use to green our energy consumption and neutralize the rest of our emissions meet the highest standards in the industry. Click to view our up-to-date Certificate of Carbon Neutralization.