Climate change science is, unfortunately, a controversial topic. Disinformation campaigns driven by political and economic opposition — both historical and current — mean that despite overwhelming evidence in support of human actions altering the climate, greenhouse gas emissions are still peaking.
While denialism is a prominent and well-known barrier to action, in this excerpt from Science Under Siege: How to Fight the Five Most Powerful Forces that Threaten Our World (PublicAffairs, 2025), authors Michael Mann, Presidential Distinguished Professor in the Department of Earth and Environmental Science at the University of Pennsylvania, and Peter Hotez, Dean for the National School of Tropical Medicine at the Baylor College of Medicine, examine another obstacle: climate doomism.
Doomism produces viral social media content — what’s been termed “climate doom porn,” marked by dramatic but unsupported claims of collapsing ice sheets, runaway warming, and imminent extinction.
Doom porn sells, and it has surely borne fruit for the polluters, petrostates, and plutocrats who are fanning its flames. Consider the vitriol directed at Katharine Hayhoe and Mike [Michael Mann] by ostensible climate advocates who insist it’s too late to act and dismiss our messaging on urgency and efficacy as “hopium,” the implication being that we are selling “hope” in the way, say, junkies on the street might sell drugs.
It’s the sort of smear you might expect from climate deniers, but instead it comes from those who ostensibly are on the side of climate action. “I loathe Mann & Hayhoe,” tweets Eliot Jacobson, a self-avowed “doomer” with a substantial Twitter following (75,000), who derides us as “hopium addicts.”
“Mann (like Hayhoe) is a serial blocker for anyone who challenges his hopium. Gimme someone else,” says another doomer on Twitter (now X).
These are just a few examples. Twitter is rife with such accusations against prominent climate scientists and climate communicators. From the standpoint of bad actors opposed to climate action, the attacks constitute a “twofer.”
The first, and most obvious, is that doom-mongering convinces many would-be climate advocates that climate action is a hopeless cause.
But the blistering attacks against mainstream climate science and scientists advance an agenda of division, dividing the rank-and-file climate activists and leading voices from the scientific community. This divisive battle has been carefully nurtured by bots and trolls, with others joining in the fray, unwittingly allowing themselves to be weaponized for the purpose of bad actors.
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Not everyone falls for it, of course. But the doomers have risen from relative obscurity to prominence in a political economy where extreme claims and vitriolic attacks go viral and create huge, almost cultlike followings that are indeed — as we will see shortly — readily monetized.
Some of the friendly fire comes from fellow scientists who have gone down the path of doomism or at least what we might call “soft doomism,” that is, emissions reductions alone are not adequate to prevent catastrophic warming. An example is Kevin Anderson, a perfectly well-respected British climate scientist. Anderson has accused the mainstream climate researchers of understating the climate-change threat to secure grant money: “The overall framing is firmly set in a politically dogmatic stone with academia and much of the climate community running scared of questioning this for fear of loss of funding, prestige, etc.”
The accusation is disturbingly similar to the (opposite) accusation by climate deniers — that climate scientists are overstating the climate threat to secure grant money. One wonders which it is. Are climate researchers understating or overstating the threat? Logic dictates it can’t be both.
Even revered climate scientist James Hansen, whose early predictions of warming proved prophetic, has gotten sucked into the vortex of soft doomism. The scientific consensus is that we can still avert a catastrophic planetary warming of 1.5 degrees Celsius (3 degrees Fahrenheit) if we rapidly reduce carbon emissions this decade.
Hansen has claimed that the climate-research community has underestimated the sensitivity of the climate to carbon dioxide emissions and that sustained carbon emissions will cause us to unavoidably cross that threshold. His rhetoric has grown increasingly heated and conspiratorial in nature, including vitriolic attacks on mainstream science and scientists, such as tweeting in late 2023: “The United Nations and COP28 are lying. They know the 1.5°C and 2°C global warming targets are dead.”
Hansen has argued that we should instead turn to potentially very dangerous “geoengineering” schemes — proposed technofixes like shooting reflective chemicals into the stratosphere to reflect back sunlight or dumping iron particulates into the oceans to fertilize the natural uptake of carbon by algae.
There are several troubling issues here. First, Hansen is conflating his dour assumptions about policy inaction with assumptions about climate physics. Second, Hansen uses this misleading framing to argue for potentially dangerous geoengineering technofixes. Such interventions suffer both from potential unintended consequences (shooting chemical particulates into the stratosphere to block out sunlight could have adverse and unpredictable impacts on our atmosphere and our climate) and from what’s known as “moral hazard” (the belief that there is a simple technofix that we can employ in the future provides an excuse for continued fossil-fuel burning today).
In the end, polluters and petrostates are the ones who benefit from high-profile climate scientists being pitted against each other. They would like nothing more than for us to accept the supposed inevitably of a fossil-fuel future, which is the overall framing.
So, we get division and deflection, with doomism in the mix. A feeding frenzy ensues. It starts with the journalists and the scientists they quote. The articles are posted on social media and provide fodder for divisive trolls and bots.
Authentic users soon get entrained into the fracas and join in on the pile-on. As a result, climate Twitter today is filled with toxic doomist messaging and assaults on leading climate communicators who are subject to an endless onslaught of “hopium” accusations from ostensible climate advocates anytime we dare claim that it’s not too late to do something about the climate crisis.
This may be the most successful gambit yet in the attack on climate action.
Excerpted from Science Under Siege: How to Fight the Five Most Powerful Forces that Threaten Our World by Michael E. Mann and Peter J. Hotez, copyright ©2025 by Michael E. Mann and Peter J. Hotez. Used with permission of PublicAffairs, a division of Hachette Book Group, Inc.
