Spam e-mail contributes severely to the emission of green house gases into the earth's atmosphere, according to research and calculations released Wednesday by anti-virus software maker McAfee Inc.

Emissions in the study were determined by correlating the electricity spent to transmit, process and filter spam e-mail, with its carbon footprint - considering that the electricity is produced with fossil fuels.

The amount of energy used per year to create, store, view and filter spam totals 33 billion kilowatt-hours, the equivalent to the electricity used in 2.4 million homes. McAfee said the amount of greenhouse gas emissions produced by that much electricity equals emissions of 3.1 million passenger cars using 2 billion gallons of gasoline.

Greenhouse gases are blamed for contributing to climate change and global warming.

Stopping spam at its source, as well investing in state-of-the-art spam filtering technology, will save time and money, and will pay dividends to the planet by reducing carbon emissions as well, said Jeff Green, senior vice president of product development and McAfee Avert Labs, in a statement today.

According to McAfee, the use of a state-of-the-art spam filter in every inbox would translate into savings of 75 percent of today's spam energy or the equivalent to taking 2.3 million cars off the road. Already, spam filtering saves the energy equivalent of taking 13 million cars off the road, the study said.

McAfee's Carbon Footprint of Spam study calculated the global energy requirements across 11 countries including the U.S., China, Australia, India and Japan among others.