As scientists sounded alarms about global warming at an international forum in Argentina this week, local research scientists announced that the solution may be as simple as planting trees.
A lot of trees.
Planting trees on marginal agricultural land could trap significant amounts of carbon dioxide, a so-called greenhouse gas that contributes to global warming, according to findings by a team of researchers from CSU-Monterey Bay and NASA Ames Research Center in Menlo Park.
The team, led by Christopher Potter of NASA Ames and Steven Klooster of CSUMB, reported their findings this week at a meeting of the American Geophysical Union in San Francisco.
The report complemented findings announced at the United Nations conference on climate change in Buenos Aires, where the World Meteorological Organization on Wednesday reported that 2004 was one of the hottest years on record. On Tuesday at that conference, the world’s chief climate scientist warned the United States that it was imperative it begin cutting carbon dioxide emissions now.
Potter, Klooster and their team believe they have at least part of the answer to that challenge.
Using data from NASA satellites, fed into computer programs at CSUMB, the team showed that a fifth of the carbon dioxide released annually from fossil-fuel emissions could be “sequestered” by planting groves of trees on marginal agricultural and rangeland areas.
The research also found that controlling infestations of insects that kill trees — contributing to carbon emissions — can help battle global warming. The dead trees not only are no longer trapping carbon dioxide, Potter said, but the decaying process emits even more.
Potter said there are currently large insect outbreaks in Canada and the United States that are killing trees “on a pretty massive scale.” Scientists are unsure whether the outbreaks are a symptom or a cause of global warming, but they know they can be caused by the sequential warmings that have been seen in record numbers in the 1990s and early this decade.
“Bugs do well under those conditions. They break out of dormant cycles faster and build up a pretty big population,” Potter said. “It may be a symbol that something big may be going on.”
Concerns over the use of pesticides to control the insects may be irrelevant, Potter said.
“It’s awfully difficult to control these pests even with those sorts of methods. They’re breaking out over areas the size of California and Canada,” he said. “I don’t think we have enough pesticides to control them at this point. If humans are helping to warm the climate, then we have to find a way to stop doing that.”
In their effort to find a tool for doing that, the team started out by identifying which areas of North America are carbon sources and which are carbon “sinks,” areas where more carbon is being retained by living vegetation than is being produced.
“Every country in the world is trying to assess whether it’s a source or a sink to the carbon cycle,” Potter said.
During a year that does not include an extreme weather condition, such as a drought, the United States is a small sink for carbon in terms of ecosystems, he said.
“But when you compare that with industrial activity,” Potter added, “it overwhelms the natural capacity and we end up being a source.”
The team used satellite data to identify carbon-source areas. Klooster and CSUMB researcher Vanessa Genovese then plugged that data into a complex computer modeling program that allowed them to make substitutions and estimate how much carbon dioxide could be retained by converting ag land from marginal crops to trees.
“If every square mile had 20 percent planted in trees, it could significantly reduce the amount of carbon emitted by power production every year,” said Potter.
The Web-based program is now available to state and federal agencies, which can use it to determine their own sink and source areas and best assess where tree plantings could be most effective.
Klooster said he doesn’t “think any one individual is going to get rich right away from it,” but some in agriculture, the power industry and state governments have discussed the possibility of offering “carbon credits” and monetary incentives for converting land into a “carbon sink.”
He said the American Electric Power Consortium is interested in using the team’s findings to help them plan where to invest in planting trees to mitigate carbon emissions. The Nature Conservancy is also interested in how the findings can direct the group in reforestation projects, the researchers said.
“We think it’s very significant,” Klooster said of the research. “Things are changing and we’d always like to see more people and more money to bring about results in a more timely fashion.”
Saving the planet may not be as easy as planting a tree, Potter said, but it could “at least slow down what’s happening to the planet.”
“Unless we actively try to take (carbon dioxide out of the atmosphere), we’re in for at least 100 years of climate change,” he said. “We’ve got to be active.”