eg magazine sustainability, resource efficiency & climate change

A report by Gartner, the industry analysts, said the global IT industry generated as much greenhouse gas as the world’s airlines - about 2% of global CO2 emissions.

Searches are powered by computers, stacked in Warehouses, all wired together. Gartner estimates that Google's data centres contain nearly one million servers, each drawing about 1 kilowatt of electricity.

“Data centres are among the most energy-intensive facilities imaginable,” said Evan Mills, a scientist at the Lawrence Berkeley National Laboratory in California. Banks of servers storing billions of web pages require power. http://technology.timesonline.co.uk/tol/news/tech_and_web/article5489134.ece

However Google says: "We have designed and built the most energy efficient data centers in the world, which means the energy used per Google search is minimal. In fact, in the time it takes to do a Google search, your own personal computer will use more energy than Google uses to answer your query."