In June, California utility Pacific Gas and Electric announced plans for phasing out its Diablo Canyon nuclear power plant, located on the central California coast. If the current timetable holds, late summer 2025 will see the first time in over six decades that the nation’s most populous state will have no licensed nuclear power providers.

This is big news. Forty years ago, Diablo Canyon stood at the middle of an intense controversy over the safety and desirability of nuclear power. Those debates stand as part of the origin story of the anti-nuclear movement; failure to stop the plant from coming online educated and galvanized a generation of anti-nuclear activists. From this perspective, Pacific Gas and Electric’s decision to replace nuclear output with renewable energy seems to be an environmental victory, a belated vindication of the anti-nuclear efforts of the 1970s.

But in the era of climate change, no decision regarding energy production is simple. California’s move away from nuclear power comes alongside a modest reappraisal of a technology that was once vilified by the vast majority of environmentalists. James Hansen, the scientist whose 1988 testimony before Congress provided climate change with much-needed visibility and political salience, has become one of a number of prominent environmentalists to support nuclear power.

The problems of waste, security and ensuring accident-free operation are as vexing as ever. But context is key, and the real but remote dangers of nuclear power may prove more manageable than the more visible – and accelerating – consequences of a warming planet.

Diablo today might be sitting on a second juncture in nuclear history in the United States, one where environmentalists will have to embrace – or even just accept – the very technology that helped teach them to be suspicious of relying too much on technical solutions to the political and social challenge of powering our society.

Atom-powered dreams

For decades before it became an activist target, nuclear power was celebrated as revolutionary science. From the first decade of the 20th century, newspapers and magazines reported the discoveries of Ernest Rutherford, Marie Curie and other nuclear pioneers. The prospect of transmuting matter – of turning one element into another – had been a dream of medieval alchemists, and journalists and their readers alike were quick to thrill to the new science.

It was frequently heralded as something new in the universe, and a symbol of mankind’s burgeoning ability to control nature. Moreover, the mere potential of releasing the energy stored by splitting or fusing atoms quickly gave rise to fantasies of technological utopia, in which innovations such as radium-infused medical treatments and uranium-powered ships would transform the world.

A generation later, the success of the Manhattan Project made such speculation seem plausible. Postwar media reveled in the prospect of all sorts of atomic miracles: electric cars, cheap power, weather control and cancer cures. In 1953, President Eisenhower gave official sanction to at least some of these dreams with his “Atoms for Peace” initiative, and his second term had barely begun when a power plant in Shippingport, Pennsylvania began supplying nuclear-produced electricity.

Additional plants quickly came online; more than 150 had been licensed by the end of the 1970s. If nuclear weapons filled midcentury Americans with thoughts of doomsday, nuclear power provided its opposite: the dream of a technology-fueled future that might help extend postwar prosperity indefinitely.

Eisenhower himself had put it this way in 1953, when announcing Atoms for Peace: “Experts would be mobilized to apply atomic energy to the needs of agriculture, medicine, and other peaceful activities. A special purpose would be to provide abundant electrical energy in the power-starved areas of the world.”

Problems emerge

Dreams depend for their vitality not just on what is said explicitly, but also upon what is left unspoken. In this case, the missing element was environmental awareness. It was not until the widespread hydrogen bomb testing of the 1950s that the true health and environmental costs of nuclear energy began to be uncovered; it would be another decade or more before concerns about power generation began to rival those of weapons development.

Diablo Canyon provides a case in point. Sierra Club officials had partnered with Pacific Gas and Electric to select the site in 1965, in the process helping to spare a different and more highly valued wilderness area. They were not particularly concerned about the nature of the proposed power plant. Their concern was simply with the intelligent management of natural resources, and Diablo raised questions about the proper balance of conservation and industrial development. While there may have been fears of a meltdown or other sort of accident, these were not nearly as pronounced as they would become in the next decade.

This cooperation between industry and environmentalists began to fray in the late 1960s. Activist networks in California targeted the plant, and new organizations formed that valued resistance over accommodation and negotiation. David Brower, the executive director of the Sierra Club, helped lead a well-publicized fight with his own board of directors; he would eventually resign to found the more radical group Friends of the Earth.

The country’s changing political climate played a role in this, as Brower and other activists evinced a Vietnam-era skepticism that saw the interests of industry and the public as inherently at odds. Corporations simply could not be trusted to adhere rigorously to safety standards, to value either human or environmental health at the expense of profitability.

Additionally, an evolving environmental movement was positioned to see nuclear power differently than its conservation-focused predecessors had. Indeed, by the 1970s, environmentalists were not simply seeking to manage the pace of modernization, but to question its premises altogether. Best-selling books such as “Silent Spring” (1962) and “The Population Bomb” (1968) had prompted readers to question whether or not unbridled growth was desirable, or even possible. High-profile disasters such as the 1969 Santa Barbara oil spill drew attention to the fragility of the natural environment, as well as the disturbing possibility that accidents were inevitable rather than anomalous.

Nuclear power was already becoming suspect because of its association with Cold War institutions, as well as the fearsome potential of radioactive contamination – which the historian of science Spencer Weart has identified as perhaps the most distinct element of nuclear fear. By the 1970s, despite the energy shocks of the time, nuclear energy became for environmentalists what fossil fuels are today: a symbol of the mistaken choices of decades past, and a clarion call for rethinking the entire energy landscape.

Much of this was already true before the infamous Three Mile Island accident in 1979. The Nuclear Regulatory Commission would ultimately conclude that the health effects were minimal – certainly nothing like environmentalists had feared could happen. But the psychological consequences were considerable, owing both to the days of uncertainty immediately after the accident and to the eerie resemblance between actual events and a recently released movie, “The China Syndrome,” which depicted a cover-up of safety hazards at a nuclear plant. A few years later, these concerns would be amplified still further through easy association with the anti-nuclear weapons activism of the early 1980s.

Softening stance?

“The history of mankind,” H.G. Wells wrote in 1914, “is the history of the attainment of external sources of power.” In the age of environmental awareness, it has also become the chronicle of human attempts to come to terms with the consequences of this attainment. Early anti-nuclear activists – at Diablo and elsewhere – were quite conscious of this, believing that its productive capacity did not outweigh the risks to nature and human health.

More recently, some environmentalists have warmed up to nuclear power. Stewart Brand, whose Whole Earth Catalog, first launched in 1968, made him an environmental movement icon, is one of the more prominent. “I’m so pro-nuclear now,” he told NPR in 2010, “that I would be in favor of it even if climate change and greenhouse gases were not an issue.”

Brand’s enthusiasm makes him something of an outlier, even among those environmentalists whose position has softened. What appears to have changed for them is not their assessment of the risks of nuclear, but an awareness that the environmental crisis is even worse than they imagined in early 1970s, in particular the threat of climate change from the buildup of greenhouse gases in the atmosphere.

What these more moderate proponents have in common – both with Brand and their still skeptical environmental brethren – is a recognition that questions of energy are not merely technical in nature. They reflect how people wish to organize their societies and their economies. These are the questions that anti-nuclear activists, among others, posed throughout the 1970s.

So it may well be that increased reliance on nuclear power will be part of the toolkit we need to survive climate change. However, that choice will come with risks – not just of meltdowns, but also of avoiding the kinds of hard questions that Diablo-era activists tried to ask: Can we power our society without resorting to industrial-scale technology with significant risks? It may not be possible – or desirable – to live with the trade-offs our appetite for energy demands of us.