Why Nuclear Fusion Won’t Solve the Climate Crisis

Why Nuclear Fusion Won’t Solve the Climate Crisis

In December 2022 scientists at the U.S. National Ignition Facility (NIF) announced a breakthrough in the decades-long effort to create an energy source based on the same nuclear fusion reactions that power the sun. An “engineering marvel beyond belief,” they proclaimed, as major newspapers quickly followed with breathless coverage. The Washington Post called it “truly something to celebrate.” Other commentators gushed about the fusion future as a solution to clean energy, global poverty, perhaps even world peace.

On inspection, the advance was rather less sensational than these reports suggested. The researchers had achieved what is known as ignition, the condition where a fusion reaction produces more energy than it took to start it. But the scale of the accomplishment is not remotely close to what would be required to generate electricity for practical use, much less herald a new era of clean energy [see “Star Power”]. The power demands as reported didn’t include the power needed to build the equipment and gear it up; the entire event lasted just a few seconds. And, ironically, the higher-than-expected energy yield damaged some of the diagnostic equipment in the experimental setup, casting doubt on whether ignition had even been achieved.

Calling this development a breakthrough in achieving “limitless zero-carbon power,” as the Financial Times put it, is like claiming that the discovery of fire was a milestone on the path to electricity. Hype like this doesn’t help the scientific community to build and maintain public trust; it risks diverting resources away from actual solutions to the climate crisis.

Scientists started working on creating fusion reactions in 1942 as part of the Manhattan Project. Physicist Edward Teller wanted to focus their attention on building a fusion bomb. That proved unrealistic, and just as a fusion bomb took a back burner to a fission weapon during the war, civilian fusion power took a back burner to fission after the war. On the sun, fusion takes place at millions of degrees. The scientific and technical challenges of harnessing fusion on Earth were simply overwhelming.

In the 1960s and 1970s physicists realized they could use lasers to heat hydrogen to a sufficiently high temperature before the gas could escape. After decades of limited progress on controlled fusion reactions, Congress allocated funds for the NIF. Construction began in 1997; the first experiments began in 2009. At the time, NIF physicist Siegfried Glenzer predicted ignition within the year.

Given the short time frame we have to face the climate crisis—achieving “deep, rapid and sustained global greenhouse gas emissions reduction” as soon as possible, in the words of the Intergovernmental Panel on Climate Change—how do we decide whether the cost of fusion research is worth the potential benefit or whether the money would be better spent elsewhere? How do we differentiate between staying the course and throwing good money after bad?

The NIF cost $3.5 billion to build, and its current annual budget is $380 million. The Fusion Energy Sciences program at the U.S. Department of Energy is slated to receive an additional $763 million, for a total of about $1.1 billion (an amount that the fusion industry says is far too low). By comparison, the 2022 budget of the National Renewable Energy Laboratory was $671 million.

Federal funding for nuclear power has long dwarfed funding for renewable energy and efficiency. According to the Congressional Research Service, from 1948 through 2018, 48 percent of federal energy R&D went to nuclear (both fission and fusion), whereas less than 13 percent went to renewables and 11 percent to energy efficiency. In 1948 that apportioning made sense because fission and fusion seemed promising, and no one much saw the need for efficiency. But the pattern has persisted: between 1978 and 2018 the share of renewables was 18 percent.

For 75 years the U.S. federal government has invested heavily in fission and fusion nuclear power with only modest gains to show. So why are we focusing on a speculative technology that will almost certainly come too late to make a meaningful contribution to avoiding climatic catastrophe?

Don’t get me wrong. We should fund fusion research because even $1.1 billion is no more than it costs per year to maintain a single aircraft carrier. But fusion is a long game that may or may not pay off. It’s not an answer to the climate crisis.

This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.

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