The Alternative

Technology Review is sunnily confident that technology is the single greatest force for expanding human possibilities. But honesty compels us to confess that technology has created the prospect of catastrophic climate change. Technology, too, must provide a solution.

This month, in a package of stories edited by our chief correspondent, David Talbot, we argue that “It’s Not Too Late”. We believe the energy technologies that could forestall the worst effects of global warming already exist. Rather than waiting for futuristic alternatives like the much-bruited “hydrogen economy,” the nations of the world could begin to control the growth of greenhouse-gas emissions today. What is lacking is any considered strategy.

The problem of anthropogenic climate change is real and urgent. Scientists still debate how quickly and ruinously the climate is changing, but it is now settled fact that our industries are changing the weather. The geological record is clear: atmospheric changes in carbon dioxide, Earth temperature, and sea levels have moved together in predictable formation for 400,000 years. Today, carbon dioxide concentrations are 40 percent higher than at any other time during that period, largely because humans burn oil, gas, and coal. According to Jim Hansen, the director of NASA’s Goddard Institute for Space Studies, we are approaching a climacteric: if the concentration of atmospheric carbon dioxide continues to grow at current rates, Earth’s temperatures will rise by 2 to 3 ºC this century, and sea levels by 15 to 35 meters. Many cities would be destroyed, hundreds of millions of people displaced.

The frightfulness of the threat has suggested what Hansen calls “the Alternative Scenario.” Other climate scientists and energy technologists use similar language for similar ideas (including MIT, the owner of Technology Review, which announced an energy initiative last year). These alternatives propose to slow or stop the growth in greenhouse gases, even as we develop carbon-free technologies that will satisfy our ever-growing demand for energy. By 2050, these pragmatists propose, we should produce as much as 30 terawatts of power without carbon emissions.

The Alternative is, above all, realistic. It accepts that in the short term, at least, we must use the technologies we have rather than those we wish might exist; and it understands that the rich world will never voluntarily accept any reduction in its accustomed manner of living, nor will the poor world surrender its legitimate aspirations to wealth.

One example of an existing, potentially clean source of energy is coal, which we examine in “The Dirty Secret,” by David Talbot. While coal has been the dirtiest of all fuels, spewing more carbon per kilowatt than any other, we could burn it more cleanly by combining the established technologies of gasification, the combined cycle, and carbon dioxide sequestration. U.S. coal companies could start building plants that use these technologies today, but they do not because they have no economic incentive to do so. This is because carbon dioxide emissions are what economists call a “negative externality” – that is, a harm done when the parties to some transaction do not bear its full costs, and a socially undesirable good is overproduced. Put more simply: until carbon dioxide has a cost, it will always be cheaper for coal companies to emit it than to capture it.

What can we do? Negative externalities can be addressed only by governments, through policies and international agreements. But what policies would best support a long-term energy strategy is a topic much debated by environmental economists. Limits on carbon dioxide emissions have disadvantages, even if supplemented with a system for trading emission credits. Such regulations are inflexible and often technologically ill conceived, and they offer energy producers little incentive to reduce emissions below the levels allowed by fiat. So far, they have not worked very well in Europe.

An attractive alternative is a Pigovian tax, where policymakers impose a price on a negative externality. Such a tax would create a cost for carbon dioxide where none existed, and so provide energy producers with an incentive to reduce emissions. Pigovian taxes have been used to reduce pollutants and discourage “sinful” behaviors like smoking, but they have one obvious disadvantage: because there is no exact mechanism for valuing a negative externality, it is possible to tax an undesirable good so much that levels fall below what is socially optimal. (We will need carbon-dioxide-emitting energy sources for the foreseeable future.) Still, Pigovian taxes on carbon dioxide emissions would have signal advantages over any alternatives: they would respond to changes in the production costs or price of energy, and they would generate government revenues.

The details of an international energy strategy are all still to be determined. But we have the means to save our civilization. Let us find the way. Write to me at [email protected].