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Extreme Science

August 24, 2010
by Michael Zielenziger
Image source: Photograph by Marcus Hanschen

Scientists are racing to determine a “tipping point” of catastrophic climate change—and to develop technologies to prevent it.

In the seething, barely perceptible world that Inez Fung’s mind inhabits these days, tropical storms pinwheel raggedly out of the Caribbean Basin. Raging grassland wildfires tumble across the intermountain west. Shrinking glaciers at the very top and bottom of the globe deform ocean currents and boost sea levels. Ocean temperatures are on the rise and precipitation patterns are changing, spurred by accelerating densities of carbon dioxide stacking up in the atmosphere and brimming in the surface of the sea.

Into this world she has interjected her own plotted universe of data points, spectrographic measurements, and logarithmic graphs that attempt to unravel the logic behind the chaos as well as the seeming cosmic connectedness that links ocean temperature readings off the Argentine coast and the amount of snowfall likely to accumulate in the High Sierra. Her three decades of inquiry into the dynamics of meteorological behavior take in the best evidence scientists can now marshal to predict both the short-term behavior and long-term trends affecting the earth’s landmasses, oceans, and atmosphere. Her work involves billions of calculations input over a long period of time into complex computer models. Yet as she reviews her latest batch of data on a sunny July morning in her spacious McCone Hall office on the Berkeley campus, taking in air temperature readings, long-range weather patterns, oceanographic measurements, and precipitation measurements, plainly Dr. Fung is not happy about what this mass of data is telling her.

Dr. Fung, a professor of environmental science and founder and former director of the Berkeley Atmospheric Sciences Center, is one of a growing group of experts on the UC campus who were laboring—long before Al Gore’s movie, An Inconvenient Truth, or the devastation of Hurricane Katrina brought home the nation’s potential vulnerability—to quantify and predict the extent to which climate change is already affecting natural phenomena, and began working to develop policy responses to keep the fragile earth from reaching some “tipping point” of no return. With more data coming in, and with more fieldwork being carried out to corroborate conjecture, these climatologists find there is far more to be concerned about.

“Now I have a knot in my stomach,” Fung says, the curve of her mouth turning southward into a tight pout, to match the pitch of her graying, pageboy haircut. “The hurricane season has already started,” she says, and the evidence points to the likelihood that more intense, Katrina-like hurricanes of the sort that devastated New Orleans and the Mississippi coast last summer are due to strike again. “The weather is getting more and more extreme.”

Fifteen, or even five, years ago the havoc that the rapid accumulation of greenhouse gases in earth’s atmosphere might wreak on weather patterns, crop behavior, and the churn of ocean currents might have been considered speculative, or somehow vaguely theoretical, science-fiction fantasies. But with a recent rush of data from tree rings, boreholes, and glacial samples all pointing in the same direction, scientists such as Fung are more convinced than ever that, as the National Research Council concluded in a paper released in June, there is a “high level of confidence” that the past few decades of the 20th century were warmer than any comparable period in the last 400 years, and that this warming will have global consequences. Such new and more accurate readings are, in turn, sending powerful tremors of concern throughout the scientific community.

The data arrive from a multiplicity of sources. Twice a day, weather balloons are released around the globe to measure nitrous oxide, methane, and carbon dioxide residing in the atmosphere. Drifting ocean sensors record sea temperatures and beam home the data via satellite. Scientists work daily to manipulate complex computer simulations to model the sea surface temperatures 200 years ago to make comparisons to the temperatures today. Satellite remote sensing and laser technology are used to measure the amounts of sunlight absorbed and reflected by ice sheets, while others attempt to see how changing rainfall patterns and rising temperatures affect foliage and the land’s ability to absorb carbon. New mathematical models also are being developed to more accurately predict patterns of cloud formation, as clouds reflect sunlight and absorb and trap various amounts of energy, depending on shape and height. For instance, lofty, narrow cloud columns associated with heavy storms will tend to block less of the sun’s radiation than wide blankets of shallow clouds. Fung says that clouds are a “very sensitive dial in the climate system.”

Understanding historical weather patterns also helps experts predict the future, so scientists also have begun to scrutinize core samples collected from deep within Antarctic ice sheets, the so-called Vostok ice core, to discern more accurately what the planetary atmosphere used to resemble. By analyzing gas bubbles trapped within these glacial samples, experts can determine the amounts of dust, carbon dioxide, methane, and other gases that were in the earth’s atmosphere hundreds of thousands of years ago. These core samples tell us, for instance, that CO2 levels never exceeded 280 parts per million before the industrial age (about 200 years ago), while today the level is nearer to 380. To add to this growing basket of more accurate data, NASA in 2008 will launch the Orbiting Carbon Observatory, a new satellite that will measure the CO2 in the earth’s atmosphere, an experiment that Fung is helping to fine-tune.

It does not ease Dr. Fung’s mind that even as we speak, the Mid-Atlantic states are being drowned by record-setting floods that threatened Trenton, New Jersey and Wilkes-Barre, Pennsylvania; that a powerful storm in Australia is causing huge waves to pummel San Francisco’s Ocean Beach; that wildfires are already breaking out across Arizona and California; or that it is way too early in the year for Texas to be facing another damaging drought.

Yet all these signals, she suggests, demonstrate that the fragile balance that keeps the earth’s ecosystem functioning properly—a complex and finely regulated series of homeostatic effects that tends to maintain its stability for generations at a time—may, like some Hollywood sci-fi film, now be spiraling out of control.

“For years we have been building models to predict the weather,” says Fung, who has been developing such complex simulations since she wrote her thesis as an MIT graduate student on the calculus of hurricanes and then eventually became a climate forecaster for NASA. “But now our weather is getting more and more extreme and this is consistent with what our theoretical predictions said. So whether it’s the melting glaciers in the Arctic or the drying of grasslands or the rising temperatures … these new observations tell us we’ve been correct—that it’s no longer merely a theoretical prediction.”

Adds Steven Chu, the Nobel Laureate in Physics who heads the Lawrence Berkeley National Laboratory, “Twenty years ago, when we talked about global warming, it was somewhat theoretical; it wasn’t real. In the last two, three, four years, we’re seeing things far more clearly,” making it far more difficult to disregard ominous trends. Whether measured in the rate of shrinkage of glaciers, or in rising air temperatures, the process of global warming “is either bad or really bad, and the public still doesn’t understand that. It’s no longer a question of certainty,” he adds, only whether we’re 68 percent or 98 percent certain that global warming is accelerating. Either way, “the vast preponderance of the evidence shows that we’re warming rapidly,” he says.

“What really has us worried is that after 20 years of observations, everything that is happening tells us we are warming, quite rapidly,” Dr. Fung explains. “When you see that four of the last five years are the warmest on record, well, then you know the die is loaded.” (Data also now show that the first half of 2006 was the warmest on record, according to the National Climatic Data Center.)

For years now, climate scientists have calculated that rising levels of carbon dioxide (from fossil fuel and forest burning) and methane (mainly from decomposing landfills and escaped natural gas) are trapping more and more of the sun’s energy closer to the earth. Meteorologists now have little doubt that the effects of global warming are profound and are radically changing our environment. Rising temperatures in the waters off the Gulf Coast coincided with the unusual intensity of last season’s hurricanes, which caused more than $100 billion worth of damage and more than 1,400 deaths. Likewise, there no longer seems to be doubt that as the earth warms, and sunlight peels away the glacial mountains that form the polar ice sheets, less of the sun’s energy is reflected away from the earth, and more is absorbed resulting in rising temperatures.

But only in the past few years have climatologists begun to calculate “second order” effects they had not previously considered. What happens, for instance, as the warming of the planet forces whole ecosystems to adapt, as soils dry out because of more rapid evaporation, or as seawater becomes fresher as glaciers melt more quickly? Most scientists had not predicted, for instance, that as polar glaciers began to melt, torrents of water would plunge down through the ice sheets by way of large tunnels and crevasses (called moulins) to the bedrock. As warmer weather increases surface melting, these streams intensify, and water pools beneath the glaciers lubricating the base, causing the ice to slide faster. And this, ultimately, hastens the process by which glaciers shrink.

Nor was it clear until recently that as rising concentrations of greenhouse gases cause the earth’s surface to warm and dry out, increasing evaporation and dieback of vegetation release more carbon dioxide into the atmosphere, which in turn makes the earth’s terrain, like disappearing ice, less able to reflect sunlight back into space. Such so-called “positive feedback loops” amplify and accelerate previously existing phenomena. In the case of the environment, the response of certain plant and geologic systems to warming is to adapt in ways that actually accelerate further warming. (In the case of the earth’s atmosphere, a “negative” feedback loop would actually be a good thing, because such reactions would tend to cool the planet.)

“There is a sinister side to synergy, which I call harmful reinforcement,” explains John Harte, professor of environmental science at Berkeley, whose long–term field research at 9,600 feet in the mountains of Colorado has attempted to replicate some of the effects of global warming before they actually take place. “These feedbacks increase the speed of the projected warming, and this is the most critical [research] going on in the whole climate story right now.”

Fung also believes that even the most sophisticated climate models now must be adjusted to assess how rising temperatures, thinning soils, and drier terrains will affect the future capacity of the earth to absorb carbon. “This suggests that we’ll have snowier winters and hotter summers and that weather events will be more serious.” But she cannot say for certain when we’ll reach a “tipping point” of no return, when the rise in the amount of greenhouse gases in our atmosphere cannot be reversed.

As the atmosphere warms, climate scientists predict, forest fires will become more severe, sea levels may rise, and California’s $45 billion wine industry could be imperiled by the end of the century.

Michael Hanemann, a professor of agricultural and resource economics who heads the Climate Change Center at Berkeley, is one of those experts trying to quantify the economic effects that climate change may impose. He has examined, for instance, what might happen if, as a result of global warming, more of Northern California’s precipitation falls as rain rather than as snow. This sounds at first like a trivial change, but Hanemann notes that the deep snowpack that accumulates in the Sierra Nevada each winter supplies one-third of California’s water supply. In addition, though 75 percent of the state’s precipitation falls in the rainy season between December and March, 75 percent of the water supply is actually used in the summer months between April and September, when the fields of the Central Valley are irrigated to grow fruits and vegetables, and suburban lawns in Southern California need to be watered.

Some economists had argued that global warming might actually increase the fertility of the nation’s fields, but Hanemann soon realized that these calculations—sensible for parts of the Midwest, perhaps–didn’t take into account how crucial a stable supply of water was to creating profitable agriculture. In California, agriculture is not possible without irrigation systems, and if the snowpack starts melting in January, and disappears by April, this would create chaos in the state’s highly designed system of dams, irrigation channels, and canals built, like the Central Valley Water Project, to funnel water 400 miles from the rainy North to the drier South. The system itself could stop functioning, Hanemann says, not because there would be a fall-off in precipitation, but because the state would have no capacity to store the excess water from winter rains until they are actually needed in August and September. He calculates the state would need to spend an additional $11 billion just to build extra storage capacity.

Hanemann also believes that rising sea levels from global warming also would prove costly to California because so many people live near the ocean or use the state’s beaches for recreation. He estimates that rising sea levels would force the state to build an estimated $3.8 billion of coastal protection in Southern California alone.

Berkeley researchers aren’t simply measuring the effects of climate change; they also hope to help reverse the trends. Dr. Fung is among a group of the nation’s leading climatologists who have signed an amicus brief to the U.S. Supreme Court in support of the 11 states, including California, Connecticut, Illinois, and Massachusetts, that have sued the Environmental Protection Agency for failing to regulate greenhouse gases, primarily the high levels of carbon dioxide in the atmosphere. They argue that the agency is mandated to protect citizens against harmful pollutants. The EPA has questioned the severity of the global warming problem, arguing it didn’t have authority to regulate carbon dioxide because it is not a pollutant, and said that the Bush administration already was taking steps to deal with climate change. In late June, the U.S. Supreme Court agreed to hear the case this fall.

Because their evidence points to the growing threat that carbon emissions are causing to the climate, Berkeley researchers also are helping California lead the way in terms of “decarbonizing” the state’s economy, reducing the amount of greenhouse gases being put into the atmosphere, and increasing the efficiency of its electrical industry. Already, the state has told Detroit’s automakers to reduce greenhouse gases their cars emit by 30 percent by model year 2009, in hopes that by setting a standard in the nation’s most populous and car-addicted state, some form of nationwide momentum will be generated. Another legislative initiative would cut the state’s greenhouse gases by 25 percent by the year 2020.

Work that began at the Berkeley Lab to pioneer energy efficiency already has kept the state from having to build three large power plants. Art Rosenfeld, the one-time particle physicist at the lab who first calculated that the U.S could export oil rather than import it if the nation chose to use energy as efficiently as Europe or Japan, helped spearhead a group that changed building codes and appliance standards, improved the energy efficiency of windows, and invented high-frequency ballast that led to the creation of the compact fluorescent lamp. “We’ve now reduced energy use per capita by 50 percent” since the 1973 oil embargo, Rosenfeld, now a member of the California Energy Commission, recently explained during a luncheon talk to Lab scientists. He hopes to boost efficiency further through legislation that would mandate that roofs across the state be painted white to reflect, rather than absorb, sunlight, and to change the circuits in the chargers that top up cell phones, electric toothbrushes, and other appliances to conserve more power.

Having pioneered efforts to reduce energy demand, Steven Chu now wants the Berkeley Lab to pioneer new forms of energy supply, especially cellulose-based fuels. An alternative to gasoline, cellulose—the abundant material in the primary cell wall of green plants—would be virtually limitless, clean-burning, and cheap, and would take less energy to produce than corn-based ethanol.

Already, policy experts at the university such as Dan Kammen, who works in the university’s Energy and Research Group, have documented that using ethanol, rather than gasoline, can cut greenhouse emissions by about 13 percent. But Chu is especially excited about the possible use of miscanthus, a weedlike plant that can grow 12 feet high, prospers in relatively arid climates, and could produce 200 gallons of fuel per dry ton. Plant enough of it, he says, “and the U.S. could become a net exporter of oil once again.” The lab is looking at ways to engineer new forms of photosynthetic microbes and plants that would make the conversion of cells of such “junk plants” into energy far more efficient.

Lab resources also are being used to explore new ways to convert sunlight into environmentally friendly energy as part of the Helios Project. This research unit is attempting to use synthetic biology and nanotechnology to create a sustainable carbon–neutral source of energy and to make solar cells cheaper to manufacture.

The rising tide of evidence about global warming, growing public concern over rising fuel costs, and the nation’s future energy security, along with the sense that the economic ascent of India and China and their growing appetite for fuel could spark global conflict, are giving the lab a greater sense of priority for energy-related research. “You’re seeing a real sea change in attitudes among members of Congress and scientists,” Chu says. “The CO2 challenge is going to be here for the next hundred years, and the country has to move aggressively to try and attack it.”

To Fung, there is no longer any scientific basis for pleading ignorance or to argue, as some have, that carbon dioxide is a naturally occurring gas that simply cannot be harmful. “The fact is that the earth is warming, and warming faster than we thought. It will only go faster. It’s like you’re about to turn on Niagara Falls,” she says.

“People say CO2 is life, so what can be so bad about it?” she adds. “Well, too much of a good thing becomes a bad thing,” just as a fever of 101 can be worrisome while a fever of 104 can prove fatal. In the end, she says, “We scientists are just going to have to get better at communicating” the growing risks the globe faces from our warming atmosphere.

Michael Zielenziger, a former Asia bureau chief for Knight-Ridder newspapers, is a visiting scholar in International Studies. His book on Japan, Shutting Out the Sun: How Japan Created Its Own Lost Generation, has recently been released by Nan A. Talese/Doubleday.

From the September October 2006 Global Warning issue of California.

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