Last week, at long last, Facebook released its carbon footprint, as well as its energy use data. How much carbon does all that liking and tagging and sharing generate?

The total annual carbon footprint per monthly active Facebook user is 269 grams. To put this number into context, one person’s Facebook use for all of 2011 had roughly the same carbon footprint as one medium latte. Or three large bananas. Or a couple of glasses of wine.

To be honest, it takes a couple of glasses of wine to get me to do anything on Facebook. But that’s just me (obviously). So that’s 269 grams of carbon a year for an active Facebook user—a drop in the bucket compared to the 48 tons of carbon the average annual household generates in a year. To continue:

Facebook’s greenhouse gas emissions—also known as our carbon footprint—from data centers, office space, employee commuting, employee air travel, data center construction and server transportation totaled approximately 285,000 metric tonnes of CO₂e (carbon dioxide equivalent, which includes greenhouse gases CO₂, CH₄, N₂O, and HFCs).

Where does Facebook get its energy?

Facebook’s energy mix was 23% clean and renewable, 27% coal, 17% natural gas, 13% nuclear and 20% uncategorized (energy that’s purchased by utilities on the spot market and can include any or all of the above categories).

The company’s goal is to inch up to 25% renewable by 2015. GreenBiz adds:

Facebook's energy mix will start to improve in 2014, when it opens a massive data center in Lulea, Sweden, about 60 miles from the Arctic Circle, located near hydropower stations on a river that generates twice as much electricity as the Hoover Dam. Facebook's newest data center, in Forest City, North Carolina, opened in April and is claimed to be one of the most energy efficient in the world. Facebook’s Prineville data center in Washington State was built to use only free cooling.

Greenpeace has been after Facebook to be more transparent in its carbon reporting, and to get the social media company to wean itself off coal, even “attacking from within” via its Unfriend Coal campaign. If Facebook can enlist its vast user network—which, by the way—comprises a population that, if granted nationhood, would be the third largest in the world—it would go a long way toward getting out the message about energy conservation, clean fuel sources, and renewables.