Holdren, delivering the David J. Rose Lecture in Nuclear Technology, noted that as of 2008, 82 percent of the world’s energy needs were being met through the use of fossil fuels — a degree of dependence he called “shocking.” And the percentage of fossil-fuel dependence is even higher in the United States and China, he said.
But the world’s energy problems are often framed in the wrong terms, he suggested. It’s not that we’re running out of energy sources, or running out of the money to pay for them. Rather, the real problems lie in “the economic, political and security risks” of being so dependent on distant sources of fuels, and in the environmental risks posed by our continuing fossil-fuel use.
Those environmental risks include the serious air pollution caused by the burning of coal, chiefly for generating electricity, and the burning of oil in vehicles, as well as the impact of the emissions from all fossil-fuel burning on “what we should be calling global climate disruption,” he said, rather than the usual terminology of global warming or climate change. That terminology underscores the fact that a whole suite of impacts — extreme storms, droughts and floods, coral bleaching, the spread of tropical pathogens and so on, not just warming — are associated with the increasing greenhouse-gas content of the atmosphere.
No silver bullets
While a decade ago people thought that the worst impacts of climate disruption could be avoided by keeping the concentration of greenhouse gases from rising above 550 parts per million, Holdren said, it is becoming clear from the appearance of harmful effects already at much lower levels that a limit of 550 ppm “is unlikely to avoid an unmanageable degree of climate change,” and that a target of 450 ppm would be “more prudent.”
There are no easy answers and no silver bullets for achieving that, he said: All of the energy alternatives to fossil fuels have “liabilities and limitations” of their own. For example, industrial-scale biofuels production can take land away from food production; hydropower and wind are limited by the availability of suitable locations; solar energy is costly and intermittent; nuclear plants are costly to build and lack an accepted solution for waste disposal; and nuclear fusion doesn’t work yet.
But while no single alternative can provide the full solution, there are plenty of good options available to help reduce the risks, he said. Showing a chart of costs and potential impacts of the different options for replacing portions of our fossil-fuel use with carbon-free alternatives, he pointed out that many of those alternatives — such as replacing lights or appliances with more efficient models, using hybrid vehicles or generating electricity from landfill gas — actually have a negative cost: That is, they save more money than they cost to implement. The only reason such alternatives are not being used is because of lack of information or various economic or regulatory barriers that need to be removed, he said — something that should be a top priority.
A second category comprises measures that have relatively low costs, and could be spurred by the adoption of even a modest cost on carbon emissions; he suggested a level of $25 per ton of carbon-dioxide equivalent would be sufficient to make many of these alternatives economically competitive, and said that while such a plan failed to pass in the present Congress, the administration will push for it again next year. As for the third category, those whose costs would still be too high even with such a price on carbon — and this includes photovoltaic systems and systems to capture and bury carbon dioxide from fossil fuel plants — the key is to do the research necessary to find ways of dramatically lowering those costs.
Nuclear power’s role
Many of these measures, he said, would not only reduce pollution and oil dependency and mitigate climate change, they would also “create new businesses, new jobs, help drive economic recovery and growth, and maintain global competitiveness.” To put that another way, he said, “If we don’t figure out how to reduce these emissions economically, other people will do so and will be selling the technologies to us.”
He said that virtually everybody who studies these issues — including the “odd couple” of the conservative American Enterprise Institute and the liberal-leaning Brookings Institute, which issued a recommendation last week — concludes that we should be spending at least three to four times as much on energy R&D as the $3.9 billion called for in the administration’s budget proposal for 2011.
Nuclear power, while not capable of making a major dent in energy production in the near term, has a potentially significant role to play, and could become a major factor in the longer term, Holdren said. He said he agrees fully with the conclusions of the recently released MIT study on the future of the nuclear-fuel cycle, calling for economic support of the first several new nuclear plants in this country, as well as for increased research on potential new fuel-cycle technologies for the longer run and for long-term spent fuel storage options.
He also endorsed the study’s call for an “interim storage” option for the spent fuel from nuclear power plants, in order to provide time for the most active components to cool down and for decisions to be made about long-term sequestration or reprocessing. He also strongly supported the study’s call for international measures to monitor and control supplies of enriched uranium and plutonium in order to avoid the proliferation of nuclear weapons.
The MIT nuclear studies, he said, “have in my judgment reached all the right conclusions,” and he has been actively circulating those documents in Washington.
The David J. Rose Lecture in Nuclear Technology is an annual lecture sponsored by the Department of Nuclear Science and Engineering. It honors the memory of David J. Rose (1922-1985), a professor of nuclear engineering at MIT who made contributions to fusion technology, energy and nuclear-waste disposal.