Fake news spread by those with a profit motive is leaving many people oblivious to the threat of climate change, says former head of US space agency

Americans are “under siege” from disinformation designed to confuse the public about the threat of climate change, Nasa’s former chief scientist has said.

Speaking to the Guardian, Ellen Stofan, who left the US space agency in December, said that a constant barrage of half-truths had left many Americans oblivious to the potentially dire consequences of continued carbon emissions, despite the science being unequivocal.

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“We are under siege by fake information that’s being put forward by people who have a profit motive,” she said, citing oil and coal companies as culprits. “Fake news is so harmful because once people take on a concept it’s very hard to dislodge it.”

During the past six months, the US science community has woken up to this threat, according to Stofan, and responded by ratcheting up efforts to communicate with the public at the grassroots level as well as in the mainstream press.

“The harder part is this active disinformation campaign,” she said before her appearance at Cheltenham Science Festival this week. “I’m always wondering if these people honestly believe the nonsense they put forward. When they say ‘It could be volcanoes’ or ‘the climate always changes’… to obfuscate and to confuse people, it frankly makes me angry.”

Stofan added that while “fake news” is frequently characterised as a problem in the right-leaning media, she saw evidence of an “erosion of people’s ability to scrutinise information” across the political spectrum. “All of us have a responsibility,” she said. “There’s this attitude of ‘I read it on the internet therefore it must be true’.”

Stofan resigned from her post at the top of Nasa in December, but said she had decided to do so before the US election results. “It wasn’t anything to do with it, but I’m glad I’m not there now,” she said.

However, she welcomed the continued commitment to Nasa’s Mars program in the most recent budget and was relieved that cuts to the agency’s Earth observation program, which contributes to climate and environment monitoring, were relatively small, at $167m (the total Earth science budget is now $1.754bn).

Throughout her career, Stofan has highlighted the role of planetary science in understanding the Earth’s environment and said it provided some of the most inarguable proof that atmospheric carbon dioxide leads to a warmer climate. She draws parallels between carbon emissions on Earth and the runaway greenhouse effect on Venus, a planet which once had oceans but is now a toxic inferno with surface temperatures approaching 500C.



The Earth is not destined for such an extreme scenario – even if all the CO2 were burned its oceans would not boil off completely – but Venus demonstrates the dramatic changes that can unfold when the fine balance of planet’s atmosphere is tipped.

“We won’t go all the way to Venus, but the consequences of putting more and more CO2 into the atmosphere are really dire,” she said. “There are models that suggest if we burn off all our fossil fuels, the Earth would become uninhabitable for humans.”

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The quest to find “habitable zones” beyond the Earth has been a major motivation throughout Stofan’s scientific career and she said that the answer to the question of the existence of extraterrestrial life-forms suddenly seems within reach.

Missions to capture water coming from the plumes of Europa and Enceladus, could yield the first indications. The search is requiring scientists to be imaginative and open-minded about what alien life might look like – it might involve complex molecules, but be DNA-free, for instance.

The uncertainty over what hypothetical alien life would even look like means that any initial discovery could be ambiguous and a source of scientific dispute, Stofan predicts. “It would be great if when we found life it was easy and we image a droplet of liquid and something goes swimming across it, no one’s going to disagree with that,” she said.

A more realistic scenario is that it would take decades for confirmation, and this reasoning is why Stofan is a strong advocate of a manned Mars mission, arguing that a robotic rover would not be capable of reliably confirming the existence of life, past or present, that might be lurking beneath the surface.

Human explorers could operate drills designed to extract soil samples from far deeper than the few inches achieved by Nasa’s Curiosity rover, or the two metres limit anticipated for Esa’s upcoming ExoMars mission, and could perform more sophisticated scientific analysis. She predicts humans could orbit the red planet within 20 years and reach the surface in 30.

“I still feel that to settle the question and to have agreement it’s going to have a lot of samples and a lot of analysis and to me that means humans,” she said.

However, she dismissed the idea, popularised by Stephen Hawking and Elon Musk, that mankind should be preparing to colonise other planets to avoid self-annihilation. “I don’t see a mass transfer of humanity to Mars, ever,” she said, adding that she had been concerned recently when a teacher told her that her pupils thought the climate “doesn’t matter as we’ll all go and live on Mars”.

“Job one is to keep this planet habitable. I’d hate us to lose focus on that,” she said.

• This article was amended on 12 June 2017. An earlier version said Stofan resigned “in December, before the US election results”. To clarify: she resigned in December, but made the decision before the election results.