John P. Holdren: "Meeting the Intertwined Challenges of Energy and Environment"

John P. Holdren

In a sobering assessment of the world's energy future, AAAS Chairman John P. Holdren told a packed auditorium at AAAS that there are no technological silver bullets to solve the persistent conflict between rising global demand for cheap energy and the environmental harm that results.

In the ninth annual AAAS Robert C. Barnard Environmental Lecture, Holdren offered a wide-ranging review of the growth in energy use over time, dispelled some myths about whether the world is running out of energy, and discussed the environmental challenges—particularly climate change—that lie at the heart of the world's energy predicament.

Holdren, the Teresa and John Heinz Professor of Environmental Policy at Harvard University and director of the Woods Hole Research Center, noted that if the world continues on a "business as usual" path, energy demand will increase 50% between 2005 and 2030, with nearly a doubling in the amount of coal-fired electrical power.

Energy production is crucial for world economic prosperity and sustainable development, but the rapid growth and continued expansion in use of fossil fuels already is producing significant climate change, Holdren said. To call it "global warming" is a misnomer, he added. The term implies a process that is gradual, uniform and benign. The more apt description, he said, is "global climate disruption," something that has been occurring more rapidly than expected as industrial society pumps greenhouse gases from burning of fossil fuels into the atmosphere at a rate of 30 billion tons a year and growing.

Yet, even at an accelerating rate of use, the problem is not that the world is running out of energy, Holdren said. The "ultimately recoverable resource" estimates for oil, gas, coal, oil shale and alternative sources such as solar and wind power, are more than sufficient to meet projected energy growth into the 22nd century, he said. Nor is the world running out of money to pay for new energy production, he said. Capital investment in new energy supply out to 2030 will require less than 1% of the world's gross economic output over that period.

The real problem, according to Holdren, remains the tension between the need for affordable energy to meet economic needs and aspirations, on the one hand, and the need to reduce the immense environmental damage that is coming from today's energy sources, on the other. No known energy option is free of question marks, he said.

Holdren ticked off the potential drawbacks for even some of the alternative energy sources that have been receiving interest. Biofuels are constrained by the competition for land and water with food, fiber, and biodiversity. Wind and hydropower are constrained by the lack of good sites where people are willing to allow windfarms or dams to be built. Nuclear energy must overcome problems of vulnerability to accidents and terrorist attack, links to nuclear weaponry, and lack of an agreed solution for radioactive waste. Even the fastest, cleanest, and surest source of emissions reductions—more efficient use of energy in buildings, industry and transportation—is hampered by a lack of enough well-informed users.

The Robert C. Barnard Environmental Lecture is held each fall at AAAS, hosted by the AAAS Science & Technology Policy Fellowships. The lectureship, endowed by the international law firm of Cleary, Gottlieb, Steen & Hamilton, honors Barnard's 50 years of service as an attorney deeply concerned with the interaction of science, law and the environment.

Holdren has been an outspoken proponent of more ambitious global efforts to address the current and looming challenges of climate change. In his 18 October address, he listed three particularly daunting challenges in the global energy future:

• How to meet the basic energy needs of the 2 billion poorest people in the world in ways that avoid the health damages from dirty traditional fuels and that provide a basis for sustainable development;

• How to reduce urban and regional air pollution and overdependence on oil despite the surging demand for more automobiles; and

• How to provide the affordable energy needed to create and sustain prosperity everywhere without wrecking the global climate with carbon dioxide from fossil-fuel burning.

Those challenges can only be met with the help of improved technologies, Holdren said, and policy innovation will be required as well. Only with better policies will we get the energy-technology innovation we need, improve basic energy services to the poor, ensure rapid diffusion of cleaner and more efficient energy technologies around the world, and devise equitable and achievable frameworks for limiting the global emission of greenhouse gases.

It is the emission of those heat-trapping gases that will continue to pose the most dangerous and difficult of all environmental problems, Holdren said. There is no longer any serious scientific argument about whether human-induced influences on climate are real. He cited data from the Intergovernmental Panel on Climate Change on human versus natural influences on climate during the period 1750 to 2005. The findings suggest that human emissions of greenhouse gases and black soot have had about 30 times the warming influence over this period as natural changes in sunlight reaching the earth.

The 1992 UN Framework Convention on Climate Change called for stabilizing greenhouse gas emissions at a level that would prevent "dangerous anthropogenic interference" with the climate system. While there remains no official consensus on what constitutes dangerous interference, Holdren argues that the benchmark already has been reached, with a wide range of harmful impacts having been documented by scientists.

Permafrost in Alaska is thawing, surface melting of the Greenland ice sheet in summer is expanding, summer sea ice in the Arctic is shrinking, glaciers are retreating, and sea level rise is accelerating, Holdren said. Floods, droughts, and heat waves have all been increasing, the total power released by tropical cyclones has increased in sync with sea surface temperatures, and the incidence of major wildfires is up globally. The World Health Organization estimates that climate change was already causing at least 150,000 premature deaths annually by the year 2000.

If the world stays on a "business as usual" path, Holdren said, such harm will only increase. Droughts will become longer and more severe. Oceans will become more acidic, with large impacts on corals and other ocean organisms that make their skeletons or shells from calcium carbonate. Extreme heat waves in Europe, already twice as frequent due to global warming, will be considered "normal" by 2050, he said. Crop yields are likely to fall in the tropics and temperate zones alike.

Faced with such daunting projections, what are society's options? Holdren said there really are only three:

• Mitigation, such as taking steps to reduce greenhouse gas emissions and slow and reverse tropical deforestation.

• Adaptation, such as changing agricultural practices, bolstering defenses against tropical diseases, and building dikes and storm-surge barriers against sea-level rise; and

• Suffering the consequences of climate-change impacts that cannot be avoided by mitigation or adaptation.

"We're already doing some mitigation, some adaptation, and some suffering," Holdren said. The question is what the future mix will be. A mitigation-only strategy makes little sense, he said, because it already is too late to avoid substantial climate change. "We're in the middle of it and we're going to get more," Holdren said. "Even if you could freeze the composition of the atmosphere instantaneously right where it is now," he said, the average global temperature would rise another 0.6 degrees C (to 1.4 degrees C above the pre-industrial level) because of the thermal inertia of the ocean.

"It takes a long time for the system to come to equilibrium," Holdren said.

And the chance of passing a "tipping point" into truly catastrophic climate changes increases as the global average temperature gets to more than 2 degrees C above the pre-industrial level. For a better than even chance of avoiding that outcome, he said, carbon dioxide levels would have to peak and start to decline no later than 2025—a very demanding goal that will be out of reach if world energy policies remain for long on their current track.

Unfortunately, he said, it's difficult to change the world energy system quickly. The global investment in energy-supply infrastructure—currently dominated by the fossil fuels whose CO2 combustion product is the biggest driver of global climate change—is about $14 trillion. The turnover time for replacing that infrastructure is about 40 years, Holdren said.

Nor is the outlook rosy for some other mitigation options. Holdren noted that reversing deforestation will be difficult because the forces driving it "are deeply imbedded in the economics of food, fuel, timber, trade and development."

Resorting to an adaptation-only strategy is not a viable option, Holdren argues, because most adaptation measures become more costly and less effective as the magnitude of climate change increases.

While there is no panacea, Holdren said much can be done to promote both adaptation and mitigation. The most important step on the mitigation side, he said, is to put a price on carbon dioxide emissions. "We're going to have to pay reduce emissions of CO2, and ultimately that might cost as much as 1 to 2% of world economic product," he said. "But that is a small cost compared to the potential damages, if we don't do it."

Holdren also urged pursuit of a new global framework for mitigation and adaptation in the period after 2012, when the current Kyoto Protocol expires; spending at least three times more money globally on research, development and deployment of new energy technologies; and expanded international cooperation in deploying those technologies. "This is a problem that you have to solve everywhere, not just somewhere," he said.

In response to questions, Holdren was reasonably upbeat about the prospects for a more aggressive national policy on climate change. He cited, among other things, the changed political makeup of the Congress, people's own experience of climate-related changes and what they have been seeing on television, and the increasing receptivity of the business community toward measures to curb greenhouse gas emissions.

Company officials have testified before Congress asking for regulation of greenhouse gas emissions on a national basis, Holdren said. "This is like the plastic thermometer in the turkey popping up to tell you it's done, when you have these companies calling on the government to regulate them," he said.

Earl Lane

29 October 2007