The delegates to the Paris climate summit reached a historic agreement over the weekend. For the first time, it commits nations to specific reductions in emissions of greenhouse gases, calling for the limitation of global warming to “well below” 2 °C and pledging financial support for the developing nations that will suffer the worst effects of dramatic climate change. Spelled out in a 31-page document that will be published in Arabic, Chinese, English, French, Russian, and Spanish, the agreement calls for the signatory countries to assess their progress toward emissions reduction goals every five years and adjust their efforts accordingly, while urging increased investment in research and development on clean energy technologies as well as an international fund of $100 billion to help the worst-affected countries adapt and survive. If the Paris agreement is implemented, the world would reach net-zero emissions before the end of this century.
Unfortunately, it also relies on emerging technologies that are barely proven, yet to be successfully commercialized, or downright illusory. Limiting the temperature rise to 2 °C or less is likely to require dramatic advances in three critical technologies: energy storage, advanced nuclear reactors, and carbon capture and storage. The first two are feasible given massive investment in both basic science and commercialization. The last is probably not.
Grid-scale energy storage is critical to moving from baseload power supplied by fossil-fuel plants to a grid powered by intermittent renewable sources such as wind and solar. The International Energy Agency has calculated that in order for the electricity sector to fully decarbonize, an additional 310 gigawatts of grid-connected energy storage will need to be deployed in the United States, Europe, China, and India. In 2014, according to GTM Research, the U.S. deployed less than 100 megawatts of grid energy storage. Total new deployments in the five major countries of the Asia-Pacific region—the fastest-growing electricity markets in the world—will reach only 37 gigawatts over the next 10 years, according to Navigant Research.
This year has seen major advances in the manufacture of high-capacity, low-cost lithium-ion batteries and progress toward new chemistries that offer even higher performance at lower costs (See “Aquion Founder Jay Whitacre on the ‘Miracle Technology’ in Batteries”). But effective energy storage at the grid scale remains far too expensive in the near term.
As a group of climate scientists headed by James Hansen, formerly of NASA, said in a statement released before the Paris talks, “There is no credible path to climate stabilization that does not include a substantial role for nuclear power.” The International Energy Agency says that worldwide nuclear capacity must more than double by 2050 in order to achieve the 2 °C target. And in many ways, the prospects for commercializing advanced nuclear technology, such as compact fast reactors and molten-salt reactors, have never been brighter; 2015 saw a number of milestones for new reactor developers, including a White House summit in October at which President Obama pledged new support for nuclear R&D and a streamlined path to licensing for innovative reactor designs by the Nuclear Regulatory Commission (see “White House Strikes a Blow for Advanced Nuclear Reactors,” “Experiments Start on a Meltdown-Proof Nuclear Reactor,” and “Advanced Reactor Gets Closer to Reality”). There are now nearly 50 companies in North America working on advanced nuclear reactor technologies, backed by more than $1.3 billion in private capital, according to Third Way, a research organization based in Washington, D.C.
But new nuclear plants remain more expensive than new natural-gas plants or even solar farms. And while major reactor-building programs are under way in China, India, and other energy-strapped countries, the heralded nuclear renaissance has been postponed in the U.S. by investors’ reluctance to fund new reactors in the face of high capital costs, poor returns, public fears, and the unsolved problem of waste disposal. Western European countries are abandoning nuclear power, not building new reactors.
Both of those technologies are sure bets, though, compared with carbon capture. According to the IEA’s road map for carbon capture and storage, we must remove and store more than two billion metric tons of carbon dioxide per year from smokestacks by 2030 in order to avoid catastrophic warming, and seven billion metric tons by 2050. Barring a major technological advance that is not currently foreseeable, those targets are unreachable. According to the Global CCS Institute, there are 22 significant carbon capture and storage projects under way around the world, with the capacity to sequester a total of 40 million metric tons of carbon dioxide per year. Several major projects, including the $1.65 billion FutureGen project in the U.S. and a billion-pound ($1.5 billion) CCS project led by the U.K. government, have been scrapped. Simply put, the technology for separating carbon dioxide from power-plant emissions—not to mention the infrastructure to transport it and store it underground—is too expensive and too cumbersome for commercial deployment. While there is intriguing research going on, there is no prospect on the immediate horizon for making it economical.
Equally fanciful are visions of “afforestation”—planting large forests to remove greenhouse gases from the atmosphere. The Australian climate scientist and author Tim Flannery has estimated that it would take a forest four times the size of the Australian continent to make even a small dent in atmospheric carbon. In its 2014 Emissions Gap Report, the U.N.’s Environmental Panel came to a similar conclusion: “Theoretically, carbon uptake or net negative emissions could be achieved by extensive reforestation and forest growth, or by schemes that combine bioenergy use with carbon capture and storage. But the feasibility of such large-scale schemes is still uncertain.”
That means any international climate scheme founded on these technologies is uncertain at best. It’s entirely reasonable to hope for rapid advances in energy storage and nuclear power over the next couple of decades. But if we rely on capturing carbon from power plants and removing it from the atmosphere to accomplish our climate goals, those hopes are likely to be dashed.