The three-year scheme aims to save one billion trees in the Amazon rainforest, by preserving more than three million hectares of trees in Acre, North West Brazil.
The broadcaster has teamed up with conservation body WWF on the project.
Sky and WWF have called for donations to the campaign with every £10 helping to save 500 trees.
The broadcaster said it would match donations to the campaign pound for pound, up to a joint target of £4 million to get the project under way.
As part of the initiative Sky1 documentary maker Ross Kemp will visit the Amazon rainforest to investigate the reality of deforestation for two documentaries to be broadcast on Sky1 HD in Spring 2010.
The campaign, Sky Rainforest Rescue, aims to protect rainforest covering over three million hectares in the state of Acre, Brazil to help combat climate change and preserve the unique habitat and species of the Amazon.
Jeremy Darroch, Sky's Chief Executive, said: 'Rainforests are crucial to the fight against dangerous climate change. Yet, an area the size of three football pitches is being destroyed every minute in the Amazon alone.'
The project forms part of a new set of commitments from Sky to help tackle climate change, including an overall target to cut its CO2 emissions by 25% (per £m/turnover) across its business by 2020. In addition, the company plans to make its buildings 20% more energy efficient and to obtain 20% of its energy requirements for all its owned buildings from onsite renewable energy in the same time frame. By 2012, Sky will cut the carbon emissions from its fleet of vans by 25% (per van) and carbon emissions from employee business travel by a further 20% (per FTE).
Sky also committed to cut the total energy consumption of newly installed Sky+HD boxes by 30% by 2012, and will be working with 50 of its most carbon intensive suppliers to help them measure their carbon footprint and reduce emissions further.