The COVID-19 pandemic is like “climate change at warp speed,” to borrow the words of the economist Gernot Wagner. Though global warming and the spread of the virus proceed at wildly different time scales–and the solutions really do look quite different–both crises have been heightened by politicians and pundits who refuse to accept scientists’ repeated warnings about the nature and size of the risks involved, which has encouraged dangerous complacency in broad swathes of the public. As we improvise our response to coronavirus, it’s crucial that the debate about the best way to tackle the pandemic doesn’t turn into one in which fidelity to science once again becomes a matter of polarized partisanship, as it has in the climate debate. 

As with climate change, the projections that scientists are making for coronavirus are horrifying. Unabated, the virus will spread quickly to most of the population and lead to massive turmoil and death. To estimate how much suffering and death we can expect under a range of different scenarios, we must rely on empirically-based quantitative models. Scientists at Imperial College in London have estimated that an uncontrolled epidemic could lead to 2.2 million deaths in the United States alone. This is an unlikely scenario, as society will take measures to slow the spread of the virus. Their paper estimates that constant vigilance through social distancing, closing schools, canceling events, and home quarantines would cut deaths in half, but not halt the spread of the virus. Similar scenarios from the Center for Disease Control see 200,000 to 1.2 million deaths in the United States. The general conclusion is that only extreme measures to suppress the spread of the virus, followed by intensive testing and monitoring, will prevent significant loss of life. 

The shuttering of much of the U.S. economy for weeks or months will come at an immense cost. But in the absence of better information about the extent of infection in the United States, public health experts recommend maintaining social distancing and other measures to slow the spread of the virus, catch up on testing, and develop an exit strategy for getting the economy back to work. The alternative–ending those measures–risks mass death and suffering. 

As with climate change, this strategy will work best if the government can intercede to help solve a set of collective action problems. As with climate change, wariness about the price of those interventions has given rise to skepticism about the reality of the threat.

Many climate skeptics argue that while real, warming from burning fossil fuels will be modest and the harm less costly than shifting the economy to clean energy. And they are often arguing within the bounds of reasonable scientific disagreement. But it is a dangerous frame from which to respond to climate risks, especially when the range of possible outcomes is large. As Bob Litterman has previously written about climate change, when dealing with financial risks it is always an urgent priority to manage risks and take into account the worst plausible case. Act too late and you may miss the window to appropriately hedge. And as my colleague Jerry Taylor has argued, when you apply that thinking to climate change, it immediately favors aggressive decarbonization. The possible–even if improbable–consequences of unconstrained climate change are too hazardous to accept. Arguments about what is the most likely scenario for climate change waste valuable time.

It’s alarming, then, that the conversation around COVID-19 is headed in the same direction. Expert and non-expert opinions that downplay the potential severity of the virus are circulating widely in conservative and libertarian media outlets, and in circles around President Trump. For example a blog post from constitutional scholar (who also embraces false climate skeptic narratives) Richard Epstein argues that predictions offered by epidemiologists “radically overestimate the death toll” from COVID-19. When he wrote this on March 12, he predicted that global deaths would reach 50,000 and U.S. deaths might top out at 500. While global deaths from COVID-19 are still under 50,000, after the U.S. total climbed above his prediction (785 at time of this publication), Epstein posted a revised prediction of 2000-2500 U.S. deaths, noting that “it’s possible” those would have to go up too. Regardless he chided governors in states instituting strong social distancing measures as “hysterical and sloppy.” Faced with plausible scenarios of mass death, informed by expert opinion, we might rather think about them as moving quickly to hedge against the possibility that the virus will prove horrific. 

In a widely circulated blog post (removed from Medium and reposted here), Aaron Ginn did his own analysis to highlight what he believed to be hysteria around COVID-19. His post was subjected to an extensive rebuttal on Twitter from Carl Bergstrom, a Professor Biology at the University of Washington and, fittingly, author of the forthcoming book Calling Bullshit: The Art of Skepticism in a Data Driven World.


Based on Bergstrom’s rebuttal, Ginn’s essay is a catalog of fallacy and error. And similarities between Ginn’s post and the opinions offered by climate skeptics are striking. The same errors in logic and analysis that we find in climate skeptic narratives appear in Ginn’s analysis. Where climate skeptics might infer too much from noisy data (recall the debate around the global warming hiatus), Bergstrom shows that Ginn fails to adjust for noisy data in a time series before making inferences about the transmissibility of COVID-19. Where climate skeptics rely on overly simplistic models to make inferences about how much global warming we should expect (the debate over climate sensitivity), Ginn uses overly simplistic models to make inferences about the nature of a slowed versus uncontrolled epidemic. And where climate skeptics will cherry-pick certain concepts to argue that the effects of climate change won’t be all bad (e.g., the greening effect of increased CO2), Bergstrom shows Ginn has cherry-picked a single study to infer that the transmission of COVID-19 will slow in summer, which scientists argue could be putting hope over experience. Those errors, in climate or epidemiology, show that even if one is citing scientific studies and data from authoritative sources, the nuances of interpreting and contextualizing information are important to understanding. That is why we have experts to help us build a picture of the full scale of plausible outcomes. 

In response to the projected costs of our escalating response to the escalating epidemic, the impulse for those on the right, who are protective of free speech and open debate, has been to defend and promote Ginn, Epstein, and others as brave, iconoclastic counterweights to the groupthink of scientific experts. Dan McGlaughlin in National Review says we should be having the debate out in the open, because the stakes of the interventions are so high. When Ginn’s post was taken down by Medium, the Wall Street Journal’s editorial board charged that “the web’s gatekeepers…want to require conformity with the judgment of expert institutions, even as many of those institutions themselves woefully misjudged the situation months or weeks ago.” 

Once again, this is a familiar storyline from the climate wars. To be sure, non-experts should be learning about COVID-19, watching new information emerge, and building an informed public dialogue about the best policy response. And virologists and epidemiologists have no monopoly on truth, especially when it comes to economic policy. But there is no reason to praise over-confident amateurs as brave truth-tellers when what they are telling us is not the truth. Go ahead and have a debate in the open. It would be valuable for Ginn, Epstein, and others to take responsibility for their mistakes and refine their opinions in the face of evidence or rebuttal. That is what scientists do. Non-experts need to do the same, because the alternative is denialism. 

None of this is to suggest that scientific predictions are beyond debate or skepticism. And there is obviously a range of possible outcomes for coronavirus, just as there is for climate change. However, to have value for public deliberation on urgent questions of life or death, skepticism about expert consensus needs to be informed by credible scientific insight and judgment. Otherwise, it is best that the debate play out between genuine experts, while the rest of us act decisively to hedge against the risks as best we can be assessed. As they come to learn more, we can refine both our estimate of the threat and our response. 

As in the debate over climate change, non-experts and experts in other fields are needed to figure out how best to respond to the risks defined by those with genuine scientific expertise in the primary subject of the crisis. Epidemiologists don’t know how to dig us out of a recession or design effective social and technological systems to monitor cases of the virus or promote behaviors to keep case numbers down before treatment or a vaccine is available. Moreover they don’t know any better than lawyers or tech mavens how to avoid further failures of governance and prevent the same problems that stalled our early response to COVID-19 from being repeated upon a reemergence of this virus or another novel one. Similarly, climate scientists don’t know how to build an economically efficient and reliable energy system or a policy context that will create demand for one. 

Unlike with climate change, we will get to see the predictions of scientists play out over the next year, as countries and states implement mitigation measures with varying levels of success. A year from now we will know more than we do now about the transmission and severity of the disease. Taking early action will prevent deaths and probably serve as a hedge against the plausible horror that scientists worry this virus could unleash. If we can build a successful response to the coronavirus, the immediacy of the results may help undo some of the skepticism of experts and mainstream science consensus. And, then maybe we can do the same with climate change.

Photo credit: Screenshot of Johns Hopkins COVID-19 Dashboard.