Trees Take on Greenhouse Gases at US Super Bowl
Author: Timothy Gardner
The National Football League is hoping to tackle the game's heat-trapping gas emissions by planting 3,000 mangroves and other trees native to Florida, but the plan could be more of an incomplete pass than a touchdown when it comes to global warming, experts said.
"It's probably a nice thing to do, but planting trees is not a quantitative solution to the real problem," said Ken Caldeira, a climate scientist at the Carnegie Institution at Stanford University.
The NFL began planting the trees in August and will finish in May. This year's Super Bowl features the Chicago Bears against the Indianapolis Colts.
The NFL claims the trees planted in Miami, and at the last two Super Bowls, make the games "carbon neutral" because the trees will eventually absorb carbon dioxide (CO2), the main greenhouse gas, emitted at the events.
Power for the game and fuel for generators at the adjacent NFL Experience Super Bowl theme park, along with its more than 1,200 vehicles, will emit about 500 tons of CO2 on Super Bowl Sunday, according to the US Oak Ridge National Laboratory.
Attempts by US companies and organizations to offset carbon are taking root as evidence mounts that heat-trapping emissions from industry and the burning of coal, oil, and gas cause global warming that could lead to deadly flooding, storms, and heat waves.
A draft of a UN report to be released Friday says there is an at least 90 percent chance that human actions are to blame for most of the warming in the past 50 years.
Contenders for the 2008 US presidential race from both major political parties want to enact US laws to limit heat-trapping emissions. That could place value on offset projects by creating a market where industry might invest in green projects in exchange for the right to pollute.
The NFL should be commended for voluntarily bringing benefits of tree planting to communities, but there are less risky ways to offset greenhouse emissions, said Philip Duffy, a climate scientist at Lawrence Livermore National Laboratory.
"If you plant a tree (CO2 reductions are) only temporary for the life of the tree," he said. "If you don't emit in the first place, then that permanently reduces CO2."
Jack Groh, the NFL's environmental coordinator, said the carbon absorbing potential of the mangroves will blossom as the trees reproduce and grow into forests. But he acknowledged that it could be hard to ensure that trees planted by children at schools -- another of the NFL's programs -- will last into the future. He said the NFL was constantly trying to learn how to make its climate-neutral program better.
Even the mangroves could succumb to fire, disease, or be cut down, any of which would release any CO2 sequestered by the trees back into the atmosphere, said Duffy.
Tree projects can give people a feel-good illusion that they are slowing global warming, the amount of carbon in fossil fuel resources is 25 times greater than could be ever sequestered in trees, said Caldeira. Offsets that reduce the amount of fossil fuels being burned, such as solar and wind farms, and perhaps nuclear energy, can be less risky, he said.
Alex Rau, a principal based in San Francisco at Climate Wedge, which advises a carbon fund for Cheyne Capital, prefers clean energy projects over tree projects. "If your objectives are entirely on the carbon ... then it is not so wise a project at the moment," he said.