Facebook’s greenhouse gas emissions totaled about 384,000 metric tons of CO2e in 2012 — a 35 percent increase from the year prior — according to the company’s annual report on carbon emissions and energy use.
This includes GHGs from data centers, office space, employee commuting and air travel, data center construction, and hardware transportation totaled.
The company’s total energy use from office space, data centers and other facilities also grew about 35 percent, from 523 million kWh in 2011 to 704 million kWh in 2012.
The increase is a result of infrastructure growth as more people use Facebook — its user base totals more than 1 billion with more people joining daily, the company says.
While Facebook expects its emissions to slow over time, due to its long-term focus on clean energy, efficiency and smart-design features such as using outside air to keep its servers cool, the company says it isn’t surprised to see its overall GHGs tick up in the near-term.
In 2011 Facebook’s per-user carbon footprint was .000249 metric tons of CO2e, or 249 grams, per monthly active user. In 2012 the carbon intensity per user was about 18 percent higher at .000294 metric tons of CO2e, or 294 grams.
Between 2011 and 2012, the company says it found more precise ways to calculate its environmental performance, including its data center Scope 2 greenhouse gas emissions from purchased electricity. Facebook says it has started calculating its data center carbon footprint using emissions factors from utilities and energy projects that power its data centers — a contractual method — instead of using located-based eGRID averages provided by the EPA and the International Energy Agency.
For example, the 2012 carbon emissions from Facebook’s Prineville, Ore., data center are almost twice as high when calculated using a utility-specific emissions factor instead of the eGRID location-based average (see chart). Additionally, the Lulea, Sweden, data center’s 2012 carbon emissions measure 158 metric tons when using location-based averages; Facebook says the contractual emissions for this data center are zero because it is powered by hydroelectricity, which is cleaner than the local grid.