Community groups from all over Northern Ireland have been challenged to come up with fresh new ways to cut their carbon emissions.
The Big Green Challenge will run for two years and competitors will be in with a chance to win a share of £1m.
Ideas can be brand new or a fresh way of applying existing solutions, and the group with the most imaginative - and proven - approach at the end of the competition will win the lion's share of the £1m put up for grabs by the National Endowment for Science, Technology and the Arts (NESTA).
The competition was launched at W5 at the Odyssey in an event attended by Stephen Peover, Northern Ireland Permanent Secretary of the Department of the Environment.
Guest speaker Professor Sue Christie, director of Northern Ireland Environment Link (NIEL) spoke about her group's work facilitating understanding of environmental issues, while the Energy Savings Trust and UnLtd (the Foundation for Social Entrepreneurs) were on hand to provide advice to entrants.
NESTA chief executive Jonathan Kestenbaum said: "We've had a massive response already to the launch, proving that people are actively looking for ways to pool their ideas and resources to make a bigger impact on climate change.
"At this stage we really want to inspire groups in Northern Ireland about what's possible and the regional event in Belfast will be a great chance to do this."
Anyone wanting to find out more about the challenge should visit www.biggreenchallenge.org.uk where they can register, or call 0845 850 1122.