The organisers had promised the London Olympics and Paralympic Games, held over around four weeks from July to September, would be "the greenest Games ever" and provide a blueprint of sustainability for future Olympics to follow.
The Olympic Park, located in a once derelict and contaminated area of East London, was transformed into a green haven for wildlife and the organisers have provided regular updates on their progress towards cutting waste, carbon and improving energy efficiency.
But they also came under fire for cancelling plans for a large wind turbine to help supply renewable energy to the park.
LOCOG activities directly associated with the games, such as energy use at venues, transport services and the supply and use of materials, generated 311,000 tonnes of carbon dioxide equivalent (CO2e), compared to 434,000 tonnes estimated earlier this year, the committee said in a report.
Energy use at Olympics' venues in particular was 31,000 tonnes of CO2e lower than expected. One way this was achieved was by renting temporary seating and other infrastructure rather than buying new and reducing floor space at venues.
Carbon emissions cuts were also made in transport as many officials, media and teams used existing public services and the Olympic Torch relay was kept in the country, avoiding the long international flights of previous relays, LOCOG said.
The overall carbon footprint of the games, from all construction work, new transport infrastructure, staging the events and spectators, was 3.3 million tonnes of CO2e, slightly lower than the 3.4 million tonnes estimated in 2009.
More than 11 million spectators attended the games, along with a workforce of around 200,000 people, and tens of thousands of athletes, officials and dignitaries.
LOCOG said due to the sheer popularity of events, spectator-related emissions were much higher than expected at 913,000 tonnes of CO2e compared to the 670,000 tonnes forecast.
"There is little that London 2012 could have done to impact directly on the majority of the spectator travel footprint as it was largely made up of air travel by overseas visitors," it said.
The Olympic Park, which will be fully open to the public by the Spring of 2014 and renamed the Queen Elizabeth Olympic Park, should continue the green legacy of the games, it said.
A large amount of materials used in construction and redevelopment will be reused and recycled, a zero-carbon neighbourhood developed and low-carbon energy supply created, the report added.
- Nature & Environment