Four Recommended Carbon Offsetters

A Tufts Climate Initiative study evaluating companies singles out four organizations because they understand the issues well and fund initiatives with tangible impacts (tufts.edu/tie/tci). We gathered numbers from the recommended outfits for a New York-London round trip; as the table reveals, each tallies emissions its own way and charges a different amount for offsets. Our advice: Calculate your emissions at a few sites, figure out a donation you're OK with, and give it to a nonprofit that'll use the money efficiently, with at least 75 percent going directly to a worthy project.

Atmosfair.de CarbonCounter.org ClimateFriendly.com NativeEnergy.com
Cost per ton of CO2 $22 $13 $20 $12
Estimated CO2
(New York-London)
3.84 tons 2.4 tons 3.64 tons 2.752 tons
Offset cost $97 $26 $60 $36
Gold Standard? Yes No Yes No
Profit Status Nonprofit Nonprofit For profit For profit
% invested in projects 80% Won't say 66% Won't say