Clicking on all those viral videos, chain emails, celebrity tweets and paparazzi photos online sucks up enough energy to rank the Internet –- if it were a country -– fifth in the world for electricity use.

That’s more power than Russia uses, according to a new report about cloud-computing from Greenpeace.

Computer servers in data centers account for about 2% of global energy demand, growing about 12% a year, according to the group. The servers, Greenpeace said, can suck up as much power as 50,000 average U.S. homes.

But most of what powers the cloud comes from coal and nuclear energy rather than renewable sources such as wind and solar, according to Greenpeace. Clusters of data centers are emerging in places like the Midwest, where coal-powered electricity is cheap and plentiful, the group said.

In its report, the organization zeroed in on 10 major tech companies, including Apple, Twitter and Amazon. Recently, the group has waged a feisty fight against Facebook, which relies on coal for 53.2% of its electricity, according to Greenpeace.

Many companies, the organization said, tightly guard data about the environmental impact and energy consumption of their IT operations. They also focus more on using energy efficiently than on sourcing it cleanly, Greenpeace said.

Yahoo landed bonus points for siting facilities near clean energy hot spots and using coal-based power for just 18.3% of its portfolio. Google got love for its extensive support of wind and solar projects and for creating a subsidiary, Google Energy, that can buy electricity directly from independent renewable power producers.

In 2005, the U.S. had 10.3 million data centers gobbling up enough energy to power all of Britain for two months, according to Internet marketing company WordStream.

Each month, electricity used to power searches on Google produces 260,000 kilograms of carbon dioxide and is enough to power a freezer for 5,400 years, according to WordStream. The searches use up 3.9 million kilowatt-hours -– the equivalent of 5 million loads of laundry.

A single spam email of the 62 trillion sent each year creates 0.3 grams of carbon dioxide. A Google search for “Soylent Green” spawns the same amount as driving a car three inches.

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-- Tiffany Hsu

Photo: Facebook displays a new server that is part of the company's efforts to become more energy efficient. Kimihiro Hoshino/AFP/Getty Images