IBM is jumping on the green bandwagon. It announced today that it is to spend $1 billion (£500 million) on making its computing centres more energy efficient.

The company is to refit the data centres it runs with various power-saving devices. It has some eight million square feet of computing centres worldwide.

IBM will use more 'virtualisation' technologies, which allow one computer to run operations for multiple machines. 'Provisioning software' will be used to switch servers to power-saving standby mode faster. And the company also plans to install new liquid-cooling systems to store power for use at peak times.

Data centres are huge halls holding servers that process online bank and shopping transactions, serve up web pages and store internet information. The centres use an enormous amount of energy due to their high electricity and air conditioning demands.

Reduce greenhouse gas emissions

IBM has promised to reduce its greenhouse gas emissions along with other big IT firms .

IBM's initiative reflects the fact that environmental responsibility is becoming part of every day business for an increasing number of companies. It is now "an input to business strategy rather than just being an output," Forrester Research analyst Christopher Mines told the Associated Press news agency.

"I think this is a strong effort by IBM to pull the pieces together. People are aware of the environmental impact of its IT shop, but many of them aren't doing anything about it so far. I think that's going to change," Mines said.