London Olympics Carbon Footprint Is 20% Lower as Venue Sizes Cut

The London Olympic organizers cut their carbon-emission forecast for staging the event by a fifth after scaling back the size of venues and renting rather than building seats, tents, and crowd barriers.

The so-called carbon footprint of the games, which begin on July 27, will be equivalent to 315,000 metric tons of carbon dioxide, the London Organizing Committee of the Olympic Games said today in an e-mailed report. That’s a decline of more than 20 percent from the 400,000 tons estimated in March 2010.

London pledged to put sustainability at the heart of the games when it won the bid to host the Olympics seven years ago. While the organizers have met targets for waste recycling and reuse, they’ve struggled to achieve goals for renewable-energy output and power consumption, and in 2009 ended a plan to offset emissions from the games by investing in clean energy abroad.

The bulk of the emission reductions detailed in today’s report stem from a decision to rent temporary seating, barriers and other infrastructure rather than buy them new. The organizers also cut 90,000 square meters [969,000 square feet] of floor space in venues, saving 15,000 tons of CO2, they said.

Energy use in venues “proved to be particularly challenging,” the committee said in the report. “London 2012 has managed to find alternative solutions that ultimately are leading to better outcomes in terms of carbon reductions, even if not by the original means envisaged.”

The Olympic Delivery Authority, responsible for building the venues, reused or recycled more than 98 percent of the waste from demolishing warehouses and other structures already on the games site, beating a 90 percent target. About 99 percent of the waste created when building the venues was reused or recycled.

The Olympic Park will get about 11 percent of its energy from renewable sources including solar panels, biomass boilers and small wind turbines, the committee said. The original 20 percent target was stymied in 2010 when organizers canceled plans for a 2-megawatt wind turbine at the site.

Rather than develop more renewable generation at the park, organizers said they’ve invested in more cost-effective energy efficiency measures in 2,800 local homes and 12 schools, compensating for the shortfall.

Today’s carbon report relates only to those emissions generated by staging the games. The total volume of greenhouse gases associated with the event over the seven years of site- clearing and construction was estimated in 2010 at 3.45 million tons of CO2. That compares with total U.K. emissions of 549.3 million tons in 2011, according to the government.