Cool Ideas

By Mike Ransdell

Carnegie Mellon researcher devises strategy to combat global warming

The ocean is growing. It has coastal cities such as Miami in its sights. It's creeping up the coastline slowly and methodically to claim new territory. It could swallow up white, sandy beaches; hotel lobbies; and airport runways. It could seep into downtown streets, onto interstates, and over seaports. It could wreak havoc on the ecosystem, displace low-income residents, and contaminate water supplies. It won't happen overnight. In fact, it could take a century or more. But a growing number of researchers, politicians, and executives of major corporations agree that it's on its way. The question is, what to do about it.

The dilemma facing Miami began thousands of miles north in Greenland. A mammoth icecap is melting at an alarming rate by some estimates. If the deterioration increases, the sea level could rise by as much as 7 feet by 2100, making much of downtown Miami, at just 5 to15 feet above sea level, and Miami International Airport, whose runways are 9 to 10 feet above seal level, vulnerable to rising tides and storm surges.

Granger Morgan, professor and head of Carnegie Mellon's Department of Engineering and Public Policy (EPP), used this extreme scenario as a backdrop for a qualifying exam for doctoral students in EPP. The students, playing analysts, were charged with exploring various options for helping a hypothetical Miami real estate holding company to chart a future course based on a "worst case" of such a sea level rise. There's no denying that the Greenland ice cap, which is above sea level, is shrinking. And there's no denying that as it thaws it's raising the level of the ocean, which has the potential to gradually devour chunks of low-lying islands and cities such as Miami, New York, London, Hong Kong, and Tokyo ... though probably not as rapidly as the EPP exam suggested. And there's no denying the cause—global warming.

Destruction to coastal cities from an expanding ocean is just one potential crisis. Climatologists are warning of a variety of problems that could be set off by rising temperatures: more frequent and more severe hurricanes, droughts and heat waves, dramatic changes in ecosystems, diminishing water supplies and shriveling crop yields in developing countries, increasing numbers of animals threatened with extinction, and disappearing of coral reefs and mangrove swamps, which are important food sources for sea life. And on and on. It's no wonder the issue has captured the attention of scientists from around the world.

Earlier this year, the Intergovernmental Panel on Climate Change (IPCC) released a summary of its much anticipated fourth report, "Climate Change 2007." More than 2,500 scientific experts from 130 countries contributed to the work, which took six years to complete. Their findings present a sobering assessment: "Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global mean sea level. Eleven of the last 12 years (1995-2006) rank among the 12 warmest years in the instrumental record of global surface temperature."

The report goes on to finger the main culprit: "Carbon dioxide [CO₂] is the most important anthropogenic greenhouse gas. The global atmospheric concentration of carbon dioxide has increased from a pre-industrial value of about 280 ppm [parts per million] to 379 ppm in 2005. The atmospheric concentration of carbon dioxide in 2005 exceeds by far the natural range over the last 650,000 years (180 to 300 ppm) as determined from ice cores."

The magnitude of the effect makes it abundantly clear that this is much more than a statistical aberration. And it certainly wasn't a surprise to Morgan, who also serves as professor in the Heinz School and Department of Electrical and Computer Engineering. "Everybody knows in the science community that the greenhouse effect is real, and if you add more CO₂ to the atmosphere, you're going to heat it up," he explains. "There's really no uncertainty about that, though there is an uncertainty about the details of how many of the changes will play out."

Clearly, with this new evidence, the global warming naysayers, many protecting their economic interests, are finding it increasingly difficult to refute the threat of global warming.

The world's worrisome climate change stems from the greenhouse effect, a natural process that warms the Earth. The atmosphere is like a transparent layer of insulation that hovers over the Earth's surface. It's made up of several gases, mainly nitrogen and oxygen, but also water vapor and trace amounts of CO₂ and other gases such as methane. When sunlight hits the Earth, about 30% bounces off. The other 70% is absorbed by the Earth and then must be radiated back into space as ultraviolet radiation, or heat energy. Gases such as CO₂ and methane absorb the heat and "trap" it in. Today the Earth is about 60° F warmer than it would be without CO₂ and similar "greenhouse gases" in the atmosphere, which makes life viable.

If that was the end of the cycle, the Earth would overheat, making it uninhabitable. But, as solar energy continues to pour in, enough heat energy bounces its way through the atmosphere and eventually escapes back into space, creating a natural equilibrium between incoming solar energy and outgoing heat energy.

But as the IPCC's report shows, this climatic balancing act began to be thrown off kilter with the start of the industrial revolution in the mid 1700s. As production blossomed, industries became more reliant on the burning of fossil fuels such as coal, oil, and natural gas to power machinery. As more fossil fuels were burned, more CO₂ was sent into the atmosphere. With more CO₂ packed into the atmosphere, more heat energy has been trapped inside. As a result, temperatures have been on the rise.

"Many people simply do not understand that it is mainly carbon dioxide from burning coal and oil and natural gas that causes climate change," says Morgan. "They think that all sorts of bad environmental practice is contributor." He points out another issue that further compounds the problem: "CO₂ isn't like other pollutants. That is, once you put it in the atmosphere, it stays there—a lot of it for a century or more. So just stabilizing emissions doesn't reverse the problem. If you stabilize emissions of carbon dioxide, they just keep accumulating, and the concentration goes up and up." Only through significant reductions, says Morgan, will we begin to see reduced concentration and a reversal of the warming trend.

To address the issue of CO₂ buildup, Morgan turned his attention to the electricity industry. Several statistics make it an obvious target: Overall, the United States generates one-quarter of the world's emissions of greenhouse gases (primarily methane, nitrous oxide, fluorinated gases, and, of course, CO₂). The nation's electricity industry in particular accounts for 38% of all CO₂ emissions in the United States, more than any other industry; more than two-thirds of the electricity in the United States is produced by burning fossil fuels. Coal, at 51.2%, is the fuel of choice for electricity generation. After dropping out of favor in the 1980s and 1990s with the rise of natural gas, coal is on the verge of a revival around the world in light of large increases in natural gas prices. According to the Department of Energy, there are 154 new coal-fired power plants proposed to be built in 38 states by 2030. That number pales in comparison to the 562 new coal-fired plants China plans to build by 2013. But even though China will soon surpass the United States in CO₂ emissions, Morgan says the United States must take the lead in cutting emissions. "Concentrations of CO₂ in the atmosphere are what matter, and China's contributions to concentration will not equal those of the U.S. until mid-century," Morgan explained in a recent presentation. "And even then, in per-capita terms, they will be only about one-quarter that of the U.S."

With EPP professors Jay Apt and Lester Lave—also his colleagues at the Carnegie Mellon Electricity Industry Center and the University-based Climate Decision Making Center—Morgan presented a strategy for weaning the electricity industry from its carbon dependency during the next 50 years.

In their 75-page report commissioned by the Pew Center on Global Climate Change, the researchers noted that to even roll back CO₂ concentrations to twice the level of pre-industrial times, current emissions would have to be reduced 65%–85% by 2100. Not an easy task, especially considering that demand is expected to rise. The researchers have outlined a policy-meets-power approach that begins with the federal government establishing "a firm regulatory timetable for reducing CO₂ emissions from the electricity industry." Waiting will only put off the inevitable, says Morgan, because there's a growing consensus among all parties that regulation is coming, if not at the federal level then at the state level. In fact, many states, led by California, are already taking regulatory matters into their own hands. Thus, failing to act now will prove costly in the long run as power companies will scramble to adopt new technologies and practices too rapidly. To hold companies' collective feet to the fire, the researchers suggest imposing a gradually increasing carbon tax on emissions or, better yet, implementing a cap-and-trade system in which companies have emissions allowances that they can trade to other power companies.

Morgan and his colleagues also recommend creating a regulatory-friendly playing field that encourages research and adoption of cost-effective, low-carbon or carbon-free electricity-generation technologies. Carbon capture and sequestration technology, for example, is a system that separates CO₂ during the electricity-generation process. Instead of releasing it into open air, the system pipes it deep underground into airtight rock formations. Although the technology is still new, all of the pieces exist today on a commercial scale, and Morgan's colleague professor Ed Rubin has done detailed analysis to show that the costs can be made affordable.

But the lack of research dollars is a major issue, according to Morgan. As difficult as it is to believe, current research and development spending in the electricity industry is "less than what's spent by the dog food industry." Morgan and his colleagues recommend that the government require all power companies to kick in at least 1% of gross revenue annually for research and development, either to projects of their own choosing or to a general fund operated by the Department of Energy.

The federal government also should take a much more aggressive approach to promoting end-use efficiency by implementing policies that offer incentives for power companies to explore new ways to curtail electricity consumption, say the researchers. Labeling programs such as Energy Star (a joint effort by the Environmental Protection Agency and Department of Energy) have proven effective in reducing consumption by helping consumers identify energy-efficient appliances and practices, but much more needs to be done.

As for the price tag on these and other recommendations, the researchers estimate that they could range from $20 billion–$60 billion per year, or 0.2%–0.6% of U.S. gross domestic product, if implemented in a "gradual and orderly manner." Although the cost is significant, the report notes that the U.S. economy flourished, "despite dire predictions," while spending 1.5%–2% of gross domestic product reducing health-threatening emissions such as sulfur dioxide and nitrogen dioxide in the 1980s and 1990s. Furthermore, the researchers point to another Pew Center report, "U.S. Market Consequences of Global Climate Change," which concludes that the future costs avoided by addressing climate change now would "likely be more than enough to offset the costs of a dramatic reduction in CO₂ emissions." What would be the impact on the price at your meter? "About a 20% increase," Morgan says. "Not trivial, but less than the difference between many states today—and not too much if you think of it in terms of saving coral reefs and polar bear habitat."

For Morgan, making the investments is not only about what's right, but also what's practical. "We're spending enormous amounts of money right now, for example, to restore the Everglades and to restore wetlands all along the Gulf Coast," he says. "If we get significant sea-level rise, all of that is going to be gone." And if that were to happen, the potential threats posed to Miami in his exam might not seem so far off.

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Carnegie Mellon researcher devises strategy to combat global warming

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