Backed by Google and Yahoo search engine technologies, the free search engine is an Australian initiative designed to combat climate change by sponsoring the planting of up to two trees for every 1,000 searches made.

"In the UK alone, people conduct over 1.5 billion Internet searches a month," says Tim Macdonald, founder of Ecocho. "If we can capture just one per cent of that traffic, we will make a significant contribution towards lowering the impact of harmful greenhouse gas emissions."

The company's agreement with search engines Yahoo and Google enables Ecocho to receive a percentage of advertising revenue. Ecocho says it will use this money to purchase carbon-offset credits through the New South Wales Government Greenhouse Gas Abatement Scheme (greenhousegas.nsw.gov.au) and KPMG (kpmg.com) will check the acquisition, registration and retirement of the carbon credits.

Ecocho aims to reinvest 70 percent of the site's revenue in carbon-offset credits and as the site progresses, it will start to support similar carbon-offsetting plans in other states and countries, says Macdonald.

There are currently other similar green search engine initiatives available on the Internet. Australia's Heap Media (heapmedia.com) launched the Google-powered Blackle (blackle.com), which reduces the energy on users' monitors by displaying a predominantly black screen. SearchGreener (searchgreener.com) also features a mostly black screen and says it uses all of its Google Ads revenues to buy approved carbon credits.

"The search engine is one of the easiest ways people can change their everyday behaviour to make a positive impact on the environment."