Google has become the latest company to adopt a carbon-neutral initiative, promising to offset 100 per cent of its emissions by the end of 2007. 

The search giant will also look at ways to cut its energy consumption and make more use of renewable energy sources.

The offsets will be purchased to negate the carbon emitted by Google's data centre energy consumption, employee vehicle emissions and hardware manufacturing.

Carbon offsets are credits purchased by companies which represent a section of reforestation.

The theory is that newly planted trees process the same amount of emitted carbon as represented in the offset, resulting in a 'neutral' level of carbon emissions.

Urs Hoelzle, senior vice president of operations at Google, said in an article on Google's official blog that the offsets would only be a small and temporary part of the programme. 

"We see carbon offsets not as a permanent solution but as a temporary tool which allows us to take full responsibility for our impact right away," he wrote.

Google will also fund research into hybrid cars and alternative energy through its Google.org philanthropy programme. 

The company has co-founded the Climate Savers computing initiative, which seeks to boost the energy efficiency of home and office PCs. 

Yahoo, Dell and Salesforce.com all have similar carbon-neutral initiatives in place.