In its efforts to be green, Yahoo! has decided to dump carbon offsets and focus on energy efficiency. The company has designed its new data center to be energy efficient rather than carbon neutral.
For companies like Yahoo, Microsoft, and Google, data centers are centerpieces of the business and consume large amounts of energy. The decision to emphasize energy efficiency is an important one. Yahoo! believes that energy efficiency will have a greater impact on the environment than a carbon neutral strategy would.
While that point is debatable, there could be other reasons for the switch. A carbon neutral strategy may be more expensive than an energy efficiency strategy. Yahoo! can maintain great control over its internal operations through an energy efficiency strategy. The company cannot control the green projects that carbon offsets fund, and those green projects are not internal to Yahoo!