Clear path, indecisive travelers

Humans have often convinced themselves that technology will save them from disaster. They've indulged in the cornucopian myth of an Earth whose resources are limitless. Some societies—the Mayans, for example—have suffered outright collapses when their technologies failed, or when energy or other material resources ran scarce. Human beings will face a similar predicament in the not-so-distant future if they place too much faith in technological approaches to climate change and not enough emphasis on necessary political and philosophical shifts. But excessive faith in technology is what my roundtable colleagues Jennie Stephens, Elizabeth Wilson, and Saleemul Huq displayed In Round One regarding wind power and rooftop photovoltaic technology.

In my first essay, I discussed several factors that constrain photovoltaic and wind technologies—their intermittency, their land requirements, and so forth. I lacked space to mention a few additional constraints. Both solar and wind energy depend on rare earth elements that will likely become scarce in 20 years or so. As recently as five years ago, China accounted for 95 percent of the world's rare-earth production, raising fears that it might exert monopolistic control. China's share of production has since dropped, but China still has the world's largest reserves of rare earths by far, and worries about monopolistic behavior persist. Meanwhile, renewable energy technologies that could function without rare earths, particularly photovoltaic technologies, are not close to commercial deployment.

And as I mentioned only in passing in Round One, the manufacture of photovoltaic panels entails carbon dioxide emissions. In fact, analyses of the life cycle of photovoltaics indicate that if manufacturing grows at an annual rate exceeding the inverse of the panels' carbon dioxide "payback" time, photovoltaics will account for more emissions in their manufacture than will be saved through their use. To illustrate, the average carbon dioxide "payback" period for photovoltaics is now about eight years—meaning that photovoltaics must grow no faster than about 12 percent annually in order to qualify as a net carbon dioxide mitigator. But in fact, photovoltaics grew at annual rate of 40 percent from 1998 to 2008, and at 59 percent between 2008 and 2014. Thus photovoltaics have been a net emitter for years. For photovoltaics to replace fossil fuels in electricity generation alone (never mind in transportation or other areas)—while growing no faster than carbon "payback" permits—perhaps 50 years will be required. Fifty years is simply too long to wait for fossil fuel replacement.

Wind power has an altogether different problem, as shown by recent research on wind farms in Kansas. This research indicates that turbines on large wind farms, as they remove kinetic energy from atmospheric flow, reduce wind speeds and thus limit generation rates. This is one reason that deployable wind energy represents a miniscule resource when measured against current energy demand. Wind energy simply cannot replace fossil fuels (even as it introduces environmental problems such as bird mortality).

Though I disagree with the technological optimism expressed by Huq, Stephens, and Wilson—optimism grounded in micro-experiences rather than a global picture of energy demand, barriers to deploying renewable energy, and the like—I agree with them on certain points. I agree with Huq, despite the problems associated with renewable energy, that "transitions from fossil fuels to clean-energy technologies must become the norm in every country—rich and poor alike." I agree with Stephens and Wilson that overcoming political, institutional, and cultural resistance to change is a key part of energy transitions (which, to me, include establishing global energy equity and reducing energy consumption).

Indeed, if solutions to non-technical problems can be implemented, emissions can be reduced quickly and significantly—buying time for improved solar technologies to mature and be deployed. But the solutions I have in mind likely differ from those that my colleagues envision. For example, I envision the world softening and ultimately eradicating national borders. This might immediately eliminate about 10 percent of global emissions because standing armies, with their massive emissions, would be reduced to a minimum. And people would, as they did for millennia before fossil fuels emerged, go where the energy is rather than the other way around, reducing both emissions and energy transport costs. Banning fossil fuel–based air and private surface transport might eliminate another 10 percentof emissions. Shrinking cities and re-ruralizing the world could save an additional 10 percent. Such changes, if made, would start the world on a path toward sustainability, peace, and equality.

The way forward is clear. But the world's willingness to embark on it is very much in doubt.