Watching the Carbon Detective

Photo courtesy UC IrvineDecember was a busy month for Earth's atmosphere. There was the news that the Bush Environmental Protection Agency had allowed power plants 15 years instead of six to reduce mercury emissions—and imposed no restrictions on carbon dioxide (CO2), a greenhouse gas that speeds global warming. At about the same time, two NASA scientists concluded that diesel fuels are responsible for as much as a quarter of all global warming and contributing to a “near worldwide melting of ice.” Then, just a couple of days later, leaders of the 41,000 members of the American Geophysical Union voted unanimously on a statement declaring that global warming is real, accelerating and caused primarily by such mundane human activities as driving. Oh, and meteorologists tell us that 2004 will likely be one of the Top 10 hottest years on record—along with seven of the last 10 years.

That was just one month—the same month in which a Bush administration official, speaking in Milan, told the world that the “science [of global warming] is flawed” and “anything but certain.”

If it's flawed, it is flawed to cataclysmic proportions. A study released by a panel of global-warming researchers on Jan. 8 in the science journal Nature concluded that hundreds of species of land plants and animals around the globe could vanish over the next 50 years if industrial nations do not curtail emissions of greenhouse gases trapping heat in the atmosphere. Such a mass extinction of millions of living beings has not been experienced on this planet since the dinosaur age.

Despite the avalanche—or maybe ice melt—of bad news, Sue Trumbore is optimistic.

Trumbore's UC Irvine business card refers to her as an Earth system science professor. She'll tell you, “I'm an isotope scientist, not an ecologist,” and you'll snicker to yourself, wishing she'd said it in a stern voice: “Damn it, Jim, I'm an isotope scientist, not an ecologist.”

What she is in essence is a carbon detective.

She came to UCI in 1991, and the Earth Systems Science Department, which she heads, is ranked among the top in the country. She and her teams use sophisticated equipment, including a high-tech apparatus called the Keck Carbon Cycle Accelerator Mass Spectrometer, to determine what becomes of CO2 released into the atmosphere, primarily through deforestation and the burning of fossil fuels.

While almost everyone agrees that the amount of CO2 in the atmosphere has risen dramatically since the industrial revolution, and that CO2 is among the greenhouse gases causing our planet to heat up, not everyone is convinced—or will publicly admit—that human activity is the main cause for the spike. Meanwhile, you can't really complain that the system's broke if you don't know exactly how it works.

Trumbore is trying to fully understand the role forests play in storing and releasing CO2. Remember your grade school charts that showed how water emits vapors that are sucked up into the sky to form clouds that eventually drop the water back to Earth in the form of rain? A similar cycle takes place with carbon, although it's much more complex. For instance, in some years a lot more carbon accumulates in the atmosphere than in others. No one's sure why.

This kind of research could have serious public-policy ramifications. Everything from the Kyoto Protocol (the international agreement aimed at averting deadly climate warming) to the Bush administration's Clear Skies Initiative (which would make skies either cleaner or smoggier, depending on who's doing the spinning) is rooted in scientific research like Trumbore's.

A bunch of smart people, mostly whitehairs, huddled in UCI's University Club this past May for a breakfast lecture Trumbore gave titled “Carbon, Forests, C14 and the Future.” It was a venue far bigger than those in which these talks are usually held, due to the keen interest.

Trumbore spoke pleasantly and somewhat nervously, not at all like a know-it-all. Using charts and photos and everything else a PowerPoint presentation entails, she told how effectively forests recycle carbon and what the consequences are for our climate and air quality. She explained that carbon spewed out of tailpipes and stored in trees eventually has to go somewhere. It doesn't just evaporate. But neither is it all accounted for. Soil, trees and other things that absorb carbon in the atmosphere are called “sinks.” Scientists refer to the destination for all the unaccounted-for carbon as “the Missing Sink.” Trumbore is trying to find the Missing Sink, a mystery that has taken her to tropical forests, frozen tundra and wooded areas back east.

In a telephone interview before the lecture, Trumbore said that despite some alarming trends in recent years, she remains hopeful about the future, although she clearly believes the United States must show leadership by setting an example for the rest of the world and doing drastically more to restrict its own CO2 output.

“If we recognize it is a global problem on one hand and don't do anything to restrain ourselves on the other,” Trumbore said, “we'll have a much more difficult time getting others around the world to rein in the carbon emissions.”

The most-recent developments on the climate front still do not dampen that optimism. Responding last week as she was “burning fossil fuel to go to meetings about the CO2 problem,” she told me, “Even though the U.S. government is not leading the way, a number of large corporations (DuPont, British Petroleum, to name a couple) have taken it upon themselves to reduce their CO2 emissions. It is not necessarily altruistic, saving energy also saves money.”

She also pointed to higher-than-expected sales of hybrid cars as a reason for hope.

“I think most people are convinced there is a problem,” she said, “we just need to let them know that their actions as individuals count, however small they seem.”

And that's why her search for the Missing Sink continues.

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