Innovative technologies hold great promise for weaning us from reliance on carbon-based fuels, but the political and economic innovations needed to make it happen may be in short supply, a leading energy specialist said recently at AAAS.
Ernest Moniz, a professor of physics and engineering systems at MIT, sketched a roadmap to a low-carbon future but acknowledged that it is not going to be easy to achieve. “I’m optimistic on the technology side,” Moniz said. “On the policy side, I’m less confident.”
The challenges are daunting. Under a business as usual scenario, energy use worldwide is predicted to double or more by 2050 and electricity demand could triple. Without a serious effort to stabilize emissions of heat-trapping greenhouse gases from carbon fuels and move to a low-carbon energy future, Moniz said, the rise in average global temperatures “will far exceed prudent levels.”
Moniz, former under secretary of the U.S. Department of Energy and a former associate director for science in the White House Office of Science and Technology Policy during the Clinton Administration, delivered the second annual AAAS-Hitachi Lecture on Science and Society on 14 October.
Unless nations stabilize global greenhouse gas concentrations in the atmosphere at no more than double their pre-industrial levels, Moniz said, climate models suggest that the temperature rise between 1990 and 2100 will most likely be about 5 degrees Celsius (9 degrees Fahrenheit).
If nations agree on a carbon policy to achieve these stabilization levels, he added, there still would be a significant probability of a 3 degrees C (5.4 degrees F) temperature rise—more than the 2 degrees C (3.6 degrees F) temperature target of ongoing climate negotiations scheduled to resume in December in Copenhagen.
Today, the atmospheric concentration of carbon dioxide is 385 parts per million (ppm). When other greenhouse gases such as methane are included, the total greenhouse gas concentration is closer to 460 ppm, Moniz said. That is already well on the way to the 550 ppm that would represent a doubling of pre-industrial levels. Indeed, to have a good shot at keeping the temperature rise to less than 2 degrees Celsius by century’s end, Moniz said, “we need to think about concentrations at 450 ppm as a more prudent goal.”
“Let’s talk reality, how hard this is,” Moniz said. “We need to accelerate technology innovation and implementation, because we cannot sustain a 85 to 90 percent carbon-based energy system for more than, say, 15 to 20 years if we are going to meet anything like this glide path to 450 or even 550 parts per million.”
A recent analysis by Henry Jacoby and Ron Prinn of MIT's Joint Program on the Science and Policy of Global Change found that any credible solution would likely have to include a major reduction in primary energy use, perhaps as much as 40 percent by the end of the century. It is difficult to envision any solution that does not reduce energy dramatically from business-as-usual levels, Moniz said.
He added that the analysis also demonstrates the need for many low-carbon technologies to achieve prudent greenhouse gas concentration levels. When Jacoby and Prinn run their analysis with only two "silver bullets"—carbon dioxide capture and sequestration for the power sector and biofuels for the transportation sector—the 550 ppm stabilization scenario calls for levels of deployment that do not seem realistic, Moniz said.
“It would require 15 billion tons of coal sequestration per year and 50 million barrels of biofuels per day,” he noted. "There undoubtedly would be major policy and system challenges to deployment at this scale.”
So given the need for multiple technology pathways, Moniz offered what he called his Michelin Guide of worthwhile approaches. In his three-star category, he calls for increased improvements in energy efficiency and pursuit of carbon-free electricity in all its forms, including nuclear power, coal and natural gas with carbon dioxide capture and sequestration, and renewable energy sources such as wind, geothermal, and solar.
He gives two stars to alternative transportation fuels, such as biofuels and electricity. He also gives two stars to improvements in electric power grids and other infrastructure upgrades for energy delivery systems, and emphasizes the importance of natural gas in the transition to a low-carbon future.
As a one-star option, Moniz said it is time to get more serious about adaptation technologies and to begin to understand geoengineering measures quantitatively. Moniz acknowledged that geoengineering was “not discussed in polite company only a few years ago” and said he remains “relatively terrified” about its prospects. But “we need to understand the options just in case we don’t get the policy, business, and technology innovations rapidly enough and are forced to contemplate a hopefully short-term geoengineering intervention,” he said.
Discussing the technologies on his three-star wish list, Moniz noted the huge upfront capital costs for building nuclear power plants. But he said nuclear almost certainly will need to play a role in any serious effort to reach a low carbon future by 2050 or beyond.
His near-term priorities for nuclear include: building 10 gigawatts of so-called “first mover” plants, subsidizing facilities with design and production innovations aimed at bringing costs down; moving spent fuel at existing nuclear plants to a centralized storage location; and doing robust R&D on nuclear fuel cycle options. To enhance the nonproliferation regime, he said, nations should pursue international fuel leasing arrangements that provide assured adequate supplies of nuclear fuel to countries with small nuclear power programs and return spent fuel to the countries of manufacture.
Moniz stressed that there is no need to rush into “closed” nuclear fuel cycles, in which spent fuels are reprocessed to separate out plutonium. “The fact is we have lots of uranium,” Moniz said. Even with a tripling of the number of U.S. power reactors, he said, there is enough uranium available to fuel the new reactors for their 50-year lifetimes.
Regarding low-carbon use of coal, Moniz said there still is much to learn about the feasibility of carbon sequestration at a very large scale, which involves the capture of carbon dioxide emissions at the power plant for injection into geological formations such as hydrocarbon reservoirs or deep saline aquifers. Since trading of carbon credits typically is a part of any carbon sequestration proposal, Moniz said it is essential to develop adequate verification and monitoring techniques in order to monetize the stored carbon dioxide.
By one estimate, 92 percent of the coal plants projected to be on line in the U.S. in 2030 already exist. Retrofitting of carbon dioxide scrubbers onto existing plants is expected to be quite expensive, and not all sites will have sufficient land and water available to house the new equipment.
“We don’t know whether we can eventually retrofit 60 percent or 10 percent of existing coal plants economically,” Moniz said. If the figure is more like 10 percent, he said, switching to natural gas as a fuel at the plants may become a critical option. The U.S. has a lot of natural gas available from unconventional sources such as shale, Moniz said, but there must be more research on the sustainable growth rate for natural gas as a power source.
When it comes to solar power, Moniz said he is “extremely bullish for the long term.” But here, too, there are unanswered questions such as how quickly solar can be scaled up for widespread use. With government support, the costs of solar have been coming down, Moniz said, and there is a very active research effort underway at MIT and elsewhere to develop new, more efficient materials for converting solar energy into electricity. At MIT, he said, at least 40 faculty members are doing research related to various types of solar energy studies.
Moniz’s technological optimism about a low-carbon future is driven in part by some of the changes he sees within the Department of Energy under the Obama administration. These include new programs aimed at fostering innovation. “There is a lot more opportunity to engage large cadres of faculty and students” in energy-related research, Moniz said. He cited economic stimulus funds aimed at clean energy technologies and the establishment of 46 Energy Frontier Research Centers.
The centers, to be established at universities, national laboratories, nonprofit organizations and private companies, will address core science challenges in areas such as carbon sequestration, electrical energy storage, advanced nuclear energy systems, biofuels and solar energy utilization. Each center will receive several million dollars a year for five years. “That’s a fantastic foundation for a real transformation in five, ten, fifteen years down the road,” Moniz said.
But as he reminded his audience several times during the lecture, Moniz is less optimistic that policymakers will make corresponding advances in economic and climate policy to accompany the new push for low-carbon technologies with the required urgency. “The road to and beyond Copenhagen is going to be a very long road, a hard road,” Moniz said. “We’ve got to get there.”
But he had a hopeful long-term outlook. “I’ve sort of come to the view that we’re going to need a lot of progress on the technology innovation side,” Moniz said. “Get the costs down and that will make the policymakers a lot more courageous.”