top of page
Schermafbeelding 2022-11-04 om 11.12.59.png

Climate scientist James Hansen: ‘The opposition to nuclear power is truly insane’

Updated: Sep 11, 2023

The young climate activists who run our Dear Greenpeace campaign are not the first to point out that nuclear power should be accepted by environmentalists as a crucial part of a climate policy. James Hansen, the renowned climate scientist, has been advocating nuclear for many years. RePlanet's editor-in-chief Marco Visscher met up with Hansen in 2017. Below is an excerpt from his book on nuclear energy.


By Marco Visscher

Photo: Columbia Climate School


He’s not exactly in a good mood. It’s odd, really. Here is one of the first and most authoritative scientists to warn about climate change, finding himself at the annual UN Climate Change Conference, where everyone is coming together to agree on lowering carbon emissions. This must be heaven!

Yet James Hansen is anything but thrilled. As we sit opposite each other, at the 2017 summit in Bonn, Germany, Hansen appears to have little faith. ‘It’s just words.’

His signature hat is on the table between us. ‘Politicians say we have to prevent catastrophic climate change,’ Hansen continues. ‘But a conference like this makes no difference. Government leaders pat each other on the back and smile politely for the camera. But all those words? Bullshit.’

It’s safe to say the world’s leading climate scientist is a little impatient.

Despite all the promises made at Climate Summits, the concentration of carbon in the atmosphere has risen sharply

He has every reason to be. Since the Kyoto Protocol in 1997, every climate treaty has had a negligible effect on greenhouse gas emissions. Despite all the promises, the concentration of carbon in the atmosphere has risen sharply. It seems we will have to learn to live with the consequences. According to Hansen, these consequences won’t be mild.

The choice of Germany as host for the UN conference should be promising. Here, wind turbines and solar panels are making unprecedented inroads. Already, the German government has spent hundreds of billions of euros on these renewables. The host country is considered a model country.

Hansen does not agree. ‘Obviously, power from solar and wind is useful,’ he explains, ‘but cannot yet be stored long-term or affordably for when the weather doesn’t cooperate.’ In such cases, it’s usually power plants using natural gas or coal that need to step in. Thus, moving away from fossil fuels by mainly using weather-dependent power is, in Hansen’s opinion, ‘not a good strategy’.

The figures prove him right. In recent years, carbon emissions from the German electricity supply have barely declined. Indeed, in the year before the climate summit in Bonn, they went up. Germany has some of Europe’s most polluting coal-fired power plants. The country’s carbon emissions per capita are above the European average.


Man from Venus

And just who is James Hansen? The son of a farmer, he was born in 1941 in a small town in Iowa, in the corn-producing heart of the United States. While studying astronomy and physics, Jim developed an interest in the dust clouds surrounding Venus. He landed a job at NASA, the US space agency. There, his attention shifted.

The ozone layer in the atmosphere was being affected by chemicals used in everything from refrigerators and air conditioning to foam plastic and aerosols. All of this contributed to a greenhouse effect – an effect that, as Hansen learned, came mainly from burning fossil fuels. What impact would that have on his home planet?

He started tinkering with a programme on what was then the world’s largest computer. During long days in the NASA lab in the heart of New York – just a few floors above Tom’s Restaurant, renowned as the eatery in Seinfeld – he developed one of the first climate models. The scientist became alarmed.

From left to right: Hansen warning for global warming at the US Congress in 1988; getting arrested during an anti-fossil fuel protest; and speaking with journalists (credit: Heinrich Böll Stiftung).


Hansen started publishing papers and giving presentations. But it was only when he was invited to address the US Congress in 1988 that climate change entered the public’s mind. His message: the Earth is getting warmer. Global warming already exists.

At that time, Hansen was head of the Goddard Institute for Space Studies, the NASA department dedicated to atmospheric change. He would remain so until he stepped down in 2013. By then, he had a hefty stack of studies to his name, held in high regard by peers.

His message at the US Congress in 1988: the Earth is getting warmer. Global warming already exists

As Hansen watched the evidence for global warming grow, he became frustrated with climate policy. Fossil fuels had been exposed as the biggest culprit. Yet coal, oil and natural gas provide some 80 per cent of global energy consumption – a share that has barely declined in the last 40 years. Electricity from solar and wind may be on the rise, but in the global energy mix, their combined output sits at around 3 per cent.

When politicians kept muddling along and he himself became a grandfather, Hansen realised: We need to do more, and fast.

Thus, the scientist became an activist. Hansen found himself handcuffed at protests against fossil fuels. He proclaimed that top executives at oil companies should be tried for high crimes against humanity and nature. He compared coal transports to ‘death trains’ heading to concentration camps.

And now, at the climate summit in Bonn, Hansen sees the future as bleak. ‘We are facing an emergency,’ he says. ‘If we don’t come up with a source of reliable zero-carbon energy soon, our children and grandchildren will have to. They will have even less time to repair the damage we cause.’

An inconvenient truth

Thankfully, solutions exist. Just before our conversation, at a press conference, Hansen talked about one of those solutions – nuclear power. From an objective point of view, this makes perfect sense. A nuclear power plant doesn’t emit any greenhouse gases, and provides electricity 24/7.

In addition, as Hansen learned, there aren’t that many success stories about weaning off fossil fuels and lowering carbon emissions. ‘But the times when countries were able to produce a lot of new zero-carbon energy in a short time,’ he says in Bonn, ‘they did it with nuclear power.’

Apparently, that is an inconvenient truth to some. At the press conference, anti-nuclear activists, gathered together in one of the front rows, shook their heads ostentatiously. Once Hansen’s presentation was over, they grabbed the microphone and started asking questions. Doesn’t Mr Hansen know nuclear power has become incredibly expensive? Where does he want to store the waste for the next tens of thousands of years? Surely, in a modern democracy, nobody in their right mind would long for a revival of nuclear power?

Hansen is used to such resistance. Throughout society, nuclear power is met with deep-rooted suspicion. For many, nuclear has something evil about it, something sneaky. To them, there is a mysterious, ominous feel to it, a threat of imminent danger. It’s almost as if the fission of atoms, as in a nuclear reactor, does not belong in this world.

Throughout society, nuclear power is met with deep-rooted suspicion. For many, nuclear has something evil about it, something sneaky

Objections to nuclear power are well known. An accident could make large areas uninhabitable. The radiation released may cause diseases and deformities far and wide. At present, there’s no way to safely store the waste for tens of thousands of years. The construction of a nuclear plant – averaging six and a half years between 2000 and 2021, but running at well over a decade for new reactors in the United Kingdom, France and Finland – simply takes too long to mean anything in terms of reaching climate goals. A terrorist gaining access to a nuclear plant could make nuclear weapons, or blow it up…

All these objections are easy to disprove, Hansen knows. But he also realises that not everyone is easily convinced. Now that he runs a small organisation and depends on donations, Hansen notices some of that rigid resistance. The vast majority of potential benefactors support his protests against oil pipeline construction and his calls for an international carbon tax, but when they hear that James Hansen, a hero to them and so many others, thinks nuclear power is actually a good idea, they flinch. Nuclear power?! It often leads to them not wanting to support his work.

Hansen shrugs. ‘So be it.’


The inevitability of nuclear

Like no other, Hansen knows the conversation about nuclear power is challenging. It’s also a conversation that’s inevitable. The role of nuclear power is not at all over. Around the world, some 440 nuclear reactors are in operation, spread across more than 30 countries, which together supply 10 per cent of all electricity. In Europe, one in four light bulbs burns thanks to a nuclear plant. On that continent, no other source produces more electricity.

It doesn’t stop there. Some 60 reactors are currently under construction, about 100 are on order or planned, and over 300 are proposed. China alone announced in late 2021 that it wants to build as many as 150 nuclear reactors in 15 years.

The interest in nuclear power is not only because the climate is changing; the world is changing as well. Even before Vladimir Putin sent his army to invade Ukraine in February 2022, commentators pointed to the dangers of strong dependence on fossil fuels from Russia. With nuclear plants, which run on uranium that can come from anywhere, society has a constant source of zero-carbon energy.

Moreover, the demand for energy will increase significantly in the coming decades. If people in poor and emerging countries aspire to a better life, they will need a lot more energy. For their own well-being, it is better if that energy comes from power plants that do not pollute the air or disrupt the climate.

We never really needed nuclear power. Today it may be different.

The interest in nuclear power is not only because the climate is changing; the world is changing as well

Yet it is too early to say that nuclear power is on the rise. Between 1999 and 2020, a total of 104 nuclear reactors were started up. However, 103 have been shut down. Nuclear power’s share of the global electricity mix has plummeted from 17 to less than 10 per cent in the past 25 years. A number of countries are determined to abandon it for good. Elsewhere, political support is fragile. An accident – not unthinkable, regardless of the chants of pro-nuclear advocates – could end construction plans just like that.

The Intergovernmental Panel on Climate Change (IPCC), the United Nations climate science body, indicates that the pace of nuclear power expansion is being ‘constrained by social acceptability in many countries due to concerns over risks of accidents and radioactive waste management’.

The costs of silence

In Bonn, Hansen makes a comparison with Galileo Galilei, the astronomer who realised 400 years ago that the Earth moves around the sun. The authorities told Galilei that he had better agree with their view of the Earth as the centre of the universe. Galilei swallowed. His silence made life a lot easier for him and he knew, Hansen tells us, that one day his findings would surface anyway.

‘But today,’ says Hansen, ‘we cannot remain silent. If we sit back and say that in a few decades’ time it will become clear that phasing out fossil fuels will not succeed without nuclear power, we will be right, but by then, it will be too late!’

James Hansen – the scientist, the activist – cannot help but tell it like it is. That’s what he does when talking about the climate, and that’s what he does when talking about nuclear power. ‘The opposition to nuclear power is truly insane,’ he sighs. ‘All these fears – about radiation, about waste, about accidents – have no basis in science. This aversion is quasi-religious and irrational.’

Is it?

Is it, really?


Marco Visscher, RePlanet's editor-in-chief, is a Netherlands-based journalist and author of several books on energy and environment. This is the prologue of his 2022 book Waarom we niet bang hoeven te zijn voor kernenergie (Why we need not fear nuclear power). An English translation will come out in 2024.




bottom of page