Perspectives — A Forum for RAND Guest Speakers

Getting Warmer

Science Closes in on an Understanding of Climate Change

Nowadays, one is hard-pressed to find anyone who does not believe that global warming is taking place and that man contributes to it. Instead, the focus has shifted to trying to understand what the climate change evidence tells us about what is happening and how fast it is happening.

An atmospheric scientist and president of the National Academy of Sciences, Ralph Cicerone has been on the front lines in helping to shape science and environmental policy, having led a 2001 study at the request of President George W. Bush to understand the current state of climate change and its impact on the environment and human health. As the guest speaker at a recent Haskins Lecture, a series endowed by former RAND trustee Caryl P. Haskins and his wife Edna to bring distinguished scholars in science-related areas to speak at RAND, Cicerone focused on the nature of climate change and the challenges that lie ahead.

A Rising Sea of Evidence

Cicerone pointed to accumulating scientific evidence of a growing imbalance between the amount of energy the earth receives from the sun and the amount it releases back into space. Carbon dioxide concentrations worldwide have increased by 35 percent in the last 100 years because people annually emit more than 8 billion tons of carbon in the form of carbon dioxide into the earth’s atmosphere from burning fossil fuels. Consequently, the atmosphere now traps an additional 1 percent of the sun’s energy near the earth’s surface. While 1 percent might not seem like much, this increase in the space of one human lifetime is unprecedented, Cicerone noted.

Ralph Cicerone as the guest speaker at a recent Haskins Lecture.
Ralph Cicerone, president of the National Academy of Sciences, credits University of California, Berkeley, physicist Art Rosenfeld with jumpstarting the push for energy-efficient appliances and homes, which has kept California’s electricity usage per capita far below that of the nation.

Where the carbon dioxide comes from is also changing. Cicerone said that world energy usage doubled from 1970 to 2005 and is projected to grow more than 70 percent in the next 20 years, mostly as a result of economic growth in countries such as India and China. “In each of the last three years,” he pointed out, “China has added nearly 100 gigawatts of electrical capacity from coal-fired power plants — more than the entire electrical capacity of a France or Germany.”

The impact of this increase in greenhouse gases has been felt in rising temperatures and sea levels and in decreasing ice levels. Cicerone drove home the point that ever more precise scientific evidence corroborates these findings. Data going back a century show that sea levels have risen on average about one and a half millimeters a year; modern, more precise, data not only confirm this trend but also show that the rate of the rise today has more than doubled in the last decade and a half. Similarly, Cicerone said that 40 years of U.S. Navy data from the Cold War era show that the ice depths in the Arctic became 40 percent thinner over that time, while satellite imagery confirms that the ice expanses themselves are also growing smaller.

An Overflowing Tub

In thinking about how to address such challenges, Cicerone used the metaphor of a tub. “We are now filling the tub with 8 billion tons of carbon in the form of carbon dioxide a year — 10 if you include tropical deforestation — while the earth’s lands and oceans have the natural ability to absorb about 3.1 billion tons of carbon per year. The tub simply cannot drain fast enough, so we must greatly decrease the inflow.”

What would it take to reduce carbon emissions by just 1 billion tons a year? (One billion tons of carbon is 3.7 billion tons of carbon dioxide.) Cicerone provided five answers. We could reduce a billion tons of carbon emissions annually by increasing the energy efficiency of all buildings worldwide by 20 to 25 percent, or by increasing the fuel efficiency of two billion cars from 30 to 60 miles per gallon, or by capturing all the carbon dioxide from 800 one-gigawatt coal-fired power plants, or by replacing 700 one-gigawatt coal-fired power plants with nuclear power plants, or by replacing those same 700 one-gigawatt coal-fired power plants with a million two-megawatt wind turbines.

Viewed in this light, mitigation can seem overwhelming, but Cicerone praised California as an example of how mitigation can work on a smaller but important scale. Both California and the United States used about the same amount of electricity per person in 1960 — around 4,000 kilowatt-hours per capita. But by 2006, national usage had tripled to about 12,000, while California usage had less than doubled to about 7,000.

What accounts for the difference? Energy-efficient appliances, particularly refrigerators. Cicerone singled out high-efficiency refrigerators and other appliances as cost-effective means to reduce energy use significantly. These improvements, he said, had been stalled by such market constraints as low consumer awareness, high initial costs, and the lack of effective policy.

But under the auspices of the California Energy Commission, the state began to set strong policy in 1976, adopting standards and regulations for appliances to make them more energy-efficient. Manufacturers initially opposed the regulations, arguing that they would make appliances too expensive. As it turned out, the standards and regulations actually stimulated the development of technology that allowed the manufacturers to meet the state specifications cost-effectively. The end result was far more energy-efficient and cost-effective appliances that met consumer needs. Electricity pricing strategies also helped to contain demand in California.

“Fuel efficiency turns out to be the one win-win strategy that satisfies all goals by reducing energy dependence, carbon dioxide emissions, and air, land, and sea pollution.”

A National and Global Fever

At the national level, mitigation efforts are often constrained by conflicting goals. If a nation’s goal is to achieve energy security or energy independence, Cicerone said, then it makes sense to focus on developing domestic coal and oil, nuclear power, and renewable resources like wind and solar power and biofuels. But if the goal is to mitigate climate change, then the focus should be on renewable energy sources, nuclear power, and carbon capture and sequestration.

Realistically, nations will pursue both goals simultaneously, requiring a delicate balancing act. But for nations struggling to balance the goals and constraints, Cicerone offered this promising insight: “Fuel efficiency turns out to be the one win-win strategy that satisfies all goals by reducing energy dependence, carbon dioxide emissions, and air, land, and sea pollution.”

On a global level, Cicerone sees the need for worldwide leadership from both political and business leaders to move beyond polarization and to deal with climate change mitigation and energy security continuously over time. “Balancing energy and climate concerns does not lend itself to a one-time solution. Leaders will need to return again and again in efforts to address changing concerns.”

Cicerone also warns that efforts aimed at climate change mitigation are no longer enough. With scientific evidence beginning to show that the rate of global warming and its consequences are increasing beyond what the computer models projected only a few years ago, the world will also need to focus on adaptation to reduce the adverse effects that will occur.

Adaptation could necessitate measures that will dramatically alter the lives of millions, perhaps billions, of people. These measures could include, among other things, changing the crop patterns in regions that become drier or wetter, developing better heat-resistant and drought-resistant plant varieties, strengthening public health and environmental defenses against an increase in tropical diseases, building new water projects either to control flooding in areas that are increasingly inundated or to capture more water in areas of increasing drought, and avoiding further development on flood plains or near seashores as ocean levels continue to rise. square