What the Coronavirus Curve Teaches Us About Climate Change

By Howard Kunreuther and Paul Slovic

The coronavirus pandemic—sadly—has introduced or reintroduced many people to the concept of an exponential curve, in which a quantity grows at an increasing rate over time, as the number of people contracting the virus currently is doing. It is this curve that so many of us are trying to “flatten” through social distancing and other mitigating measures, small and large.

It’s easy to project a pattern of smooth, linear growth: one person gets the coronavirus today, another person contracts it tomorrow, a third person gets it on the third day, and the process continues in this manner, the cases simply adding. But most people, including leaders and policymakers, have a harder time imagining exponential growth, which means you can have two cases of coronavirus tomorrow, four on the third day, hundreds after the seventh day and thousands soon after—a situation that’s challenging to anticipate and manage. That’s the nature of pandemics.

It’s also how climate change works. And if there’s any silver lining in this mess, it’s that the coronavirus pandemic is teaching us a valuable lesson about the perils of ignoring destructive processes—and perhaps even larger, longer-term disasters—that increase exponentially. Even if growth looks mild in the moment—think of the earliest segments on an exponential curve like the red line shown in the illustration above—it will soon enough be severe. In other words, delay is the enemy.

The human mind does not easily grasp the explosive nature of exponential growth. This was demonstrated more than 40 years ago in a series of pioneering psychological experiments conducted in the Netherlands by Willem Wagenaar and his colleagues. In one study, participants were shown a hypothetical index of air pollution beginning in 1970 at a low value of 3 and rising yearly in an exponential way to 7, 20, 55 and, finally, 148 by 1974. Asked to intuitively predict the index value for 1979, many of the respondents produced estimates at or below 10 percent of the correct value of about 21,000 (which can be determined from the underlying exponential equation). Subsequent experiments have observed similarly dramatic underestimation of exponential growth and showed that it typically results from straight-line projections based on early small increases.

The deceptive nature of exponential growth is similarly conveyed by the riddle of a single lily pad in a pond. Suppose each member of this species reproduces once a day so that on the second day there are two lily pads, on the third day there are four, on the fourth day there are eight, etc. On Day 48, the pond is covered completely. How long did it take to be covered halfway? The answer is 47 days. Moreover, even after 40 days of exponential growth, you would barely know the lily pads are there, as they would cover only 1/256th (0.4 percent) of the pond at that time. For a period of time, we can easily ignore the steady exponential growth of lily pads—until they smother the pond.

With respect to the coronavirus, the initial doubling of the relatively small numbers of infected cases and deaths evoked little concern outside China in January and most of February, since, for weeks, people around the world had little or no personal exposure to the virus or its victims. But the deceptively mild and seemingly faraway beginnings of the current pandemic led health officials and governments to squander many opportunities for early intervention. As a result, in the past few weeks, the numbers have quickly become a torrent overwhelming our capacity to stop the virus’ spread and care for the victims. It took 67 days to reach 100,000 coronavirus cases worldwide. The second 100,000 cases took 11 days, and the third 100,000 took only four days. Public-health authorities are now scrambling to communicate just how steep and damaging the coronavirus growth curve has or could become, and urgent response is becoming the law of the land.

Aside from the coronavirus pandemic, the biggest, most destructive exponential growth processes that we must grapple with today are those associated with global climate change. While it might be hard for humans to detect that carbon emissions and their concentration in the atmosphere are growing exponentially right now, that doesn’t mean we should rest easy. The opposite is true. As with the coronavirus, we need to anticipate the climate crisis and act quickly and aggressively to minimize further damages before they overwhelm us.

Scientists have long recognized that carbon dioxide emissions and their resulting effects have been increasing exponentially. Figure 1 shows the monthly average carbon dioxide concentration measured at Mauna Loa Observatory in Hawaii—the longest record of direct measurements of CO2 in the atmosphere. The volume of CO2 stood at 315 parts per million (ppm) when first measured in 1958; by the end of February 2020, it had risen by 31 percent to 414 ppm.

That might not sound all that worrisome on the surface. But this exponential increase signals that CO2 emissions are likely to be considerably higher in the coming years, unless we take strong measures now to reduce them. Otherwise, the exponential growth of CO2 emissions will drive our climate to extremes that look nothing like a linear extrapolation of recent history. We will experience more blistering heat waves, severe droughts, accelerating sea level rise, and unprecedented intensity of rainstorms and resulting flooding, just to name a few of the consequences.

Or consider another example of exponential growth related to increasing CO2 emissions: financial losses caused by climate change-related flooding, combined with population growth. A 2013 analysis in 136 major coastal cities around the world reveals that sea level rise (SLR) of 20 cm (7.9 inches) by 2050—an optimistic scenario—will cause the average annual flood losses in those cities to increase to $1.2 trillion that year from $52 billion in 2005. A more pessimistic scenario of SLR of 40 cm (15.7 inches) by 2050 will lead to average annual flood losses of $1.6 trillion. Houston was one of the 20 most vulnerable coastal cities in the study, and its average annual damage with an optimistic SLR scenario is estimated to increase by 78 percent, from $5.1 billion in 2005 to $9.1 billion in 2050.

People are actually moving into harm’s way, not realizing the potential for severe damage they might suffer in the coming years due to climate change. From 1980 until 2018, the population of hurricane-prone counties in Florida increased by 163 percent, from 3.7 million people to 9.8 million, compared with a 61 percent increase in the population of the United States during this period. These Florida residents might not recognize that they are likely to experience increased damage from more intense hurricanes coupled with sea level rise due to climate change.

If carbon emissions continue to grow exponentially, most of the United States could see 20 to 30 more days annually with maximum temperatures higher than 90 degrees, with the Southeast potentially enduring 40 to 50 more such days. This extreme heat poses serious health risks, especially for the very young and the elderly, construction and agricultural workers, and those living in the core of urban areas. Wildfires present another problem that is growing exponentially and is exacerbated by global warming, as temperatures rise and humidity falls. California experienced a particularly drawn-out drought from December 2011 to March 2019 that contributed to extensive wildfire damage that is likely to increase significantly in the future because of climate change.

Taking a lesson from our flat-footed response to the coronavirus pandemic, we can no longer delay aggressive actions to halt and reverse what otherwise will be inevitable pandemic-like crises arising from climate change. Already, tipping points have been reached: Human populations and cultures are being devastated, and many species are becoming extinct.

Obviously, dealing with the present dangers from the coronavirus must be everyone’s top priority at this moment. We will eventually get control of this demon and begin to restore some semblance of normal life. When we do, the world must turn its attention to reducing CO2 emissions and stopping the further exponential havoc that climate change will wreak, far sooner than we expect.

Michael Oppenheimer, Andrew Quist, Quinlyn Spellmeyer, Carol Heller and Cameron Slovic contributed to this article.

  • Suspected SARS virus and flu samples found in luggage: FBI report describes China's 'biosecurity risk'
    Yahoo News

    Suspected SARS virus and flu samples found in luggage: FBI report describes China's 'biosecurity risk'

    In late November 2018, just over a year before the first coronavirus case was identified in Wuhan, China, U.S. Customs and Border Protection agents at Detroit Metro Airport stopped a Chinese biologist with three vials labeled “Antibodies” in his luggage. The biologist told the agents that a colleague in China had asked him to deliver the vials to a researcher at a U.S. institute. “Inspection of the writing on the vials and the stated recipient led inspection personnel to believe the materials contained within the vials may be viable Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS) materials,” says an unclassified FBI tactical intelligence report obtained by Yahoo News.

  • Trump says Democrats' push for expanded voting threatens Republicans
    Yahoo News

    Trump says Democrats' push for expanded voting threatens Republicans

    President Trump on Monday criticized attempts by Democrats in Congress to expand voting access for the presidential election in the fall, saying increased voter turnout would keep Republicans from getting elected. Trump said that Democrat-proposed voting reforms to the $2.2 trillion rescue package passed last week by Congress — which were largely cut from the deal — would have led to “levels of voting, that if you ever agreed to it you'd never have a Republican elected in this country again.” Democrats have pushed to mandate that states make plans to expand early voting and mail-in balloting for the fall election, in the event that the coronavirus pandemic makes in-person voting unsafe.

  • Boy, 5, found dead near hiking trail after mother said they got lost
    NBC News

    Boy, 5, found dead near hiking trail after mother said they got lost

    The body of a 5-year-old boy was discovered near an Alaskan trail after his mother said they got lost during a hike. A ground search team found the child, Jaxson Brown, around 2:45 p.m. on Saturday, three days after he and his mother went for a hike along Lunch Creek Trail in Ketchikan. The boy's mother, Jennifer Treat, told Alaska State Troopers that she and Jaxson went on a hike Wednesday afternoon.

  • FBI report describes China’s ‘biosecurity risk’
    Yahoo News Video

    FBI report describes China’s ‘biosecurity risk’

    In late November 2018, just over a year before the first coronavirus case was identified in Wuhan, China, U.S. Customs and Border Protection agents at Detroit Metro Airport stopped a Chinese biologist with three vials labeled “Antibodies” in his luggage.

  • The CDC is said to be considering asking people to cover their face in public — but would reserve masks for medical workers
    Business Insider

    The CDC is said to be considering asking people to cover their face in public — but would reserve masks for medical workers

    Romeo Ranoco/Reuters The Centers for Disease Control and Prevention may start urging Americans to cover their faces in public amid the coronavirus outbreak, according to The Washington Post. If the advice is updated, The Post reported, the CDC would stress that surgical masks and N95 masks should be saved for medical professionals and that others should make their own masks. The CDC's current advice is to wash hands, obey social-distancing advice, and stay at home.

  • 29 Best Closet Organization Ideas to Maximize Space and Style
    Architectural Digest

    29 Best Closet Organization Ideas to Maximize Space and Style

    How to organize your closet like a pro Originally Appeared on Architectural Digest

  • Venezuela prosecutor's office summoned Guaido for 'attempted coup'
    AFP

    Venezuela prosecutor's office summoned Guaido for 'attempted coup'

    State prosecutors in Venezuela have summoned opposition leader Juan Guaido for an alleged "attempted coup d'etat" and attempted assassination, Attorney General Tarek William Saab announced Tuesday. In a statement broadcast on state television, Saab said Guaido had been summoned to appear before prosecutors next Thursday following an investigation last week into the seizure of a weapons cache in neighboring Colombia that he said was to be smuggled into Venezuela. The subpoena was delivered to his head of security on Monday night, Saab said.

  • Fit, healthy 33-year-old recounts falling ill to coronavirus
    Associated Press

    Fit, healthy 33-year-old recounts falling ill to coronavirus

    Still, Napoli, a lawyer in Rome, developed a cough and fever less than a week after Italy's premier locked down the entire nation, including the capital which had continued life as usual while the virus raged in the north. Until that day, Napoli was following his routine of work, jogging and swimming. He received a positive diagnosis for COVID-19 three days later.

  • Indian police fire tear gas at jobless workers defying coronavirus lockdown
    Reuters

    Indian police fire tear gas at jobless workers defying coronavirus lockdown

    Police in India fired tear gas to disperse a stone-pelting crowd of migrant workers defying a three-week lockdown against the coronavirus that has left hundreds of thousands of poor without jobs and hungry, authorities said on Monday. Prime Minister Narendra Modi ordered the country's 1.3 billion people to remain indoors until April 15, declaring such self-isolation was the only hope to stop the viral pandemic. But the vast shutdown has triggered a humanitarian crisis, with hundreds of thousands of poor migrant laborers employed in big cities such as Delhi and Mumbai seeking to head to their homes in the countryside on foot after losing their jobs.

  • Wuhan Residents Dismiss Official Coronavirus Death Toll: ‘The Incinerators Have Been Working Around the Clock’
    National Review

    Wuhan Residents Dismiss Official Coronavirus Death Toll: ‘The Incinerators Have Been Working Around the Clock’

    Wuhan residents are increasingly skeptical of the Chinese Communist Party's reported coronavirus death count of approximately 2,500 deaths in the city to date, with most people believing the actual number is at least 40,000. “Maybe the authorities are gradually releasing the real figures, intentionally or unintentionally, so that people will gradually come to accept the reality,” a Wuhan resident, who gave only his surname Mao, told Radio Free Asia. A city source added that, based on the aggregation of funeral and cremation numbers, authorities likely know the real number and are keeping it under wraps.

  • Trump now says if 100,000 Americans die from coronavirus he will have done 'a very good job'
    Yahoo News

    Trump now says if 100,000 Americans die from coronavirus he will have done 'a very good job'

    At the first formal press briefing with his coronavirus task force on Feb. 26, President Trump said he didn't agree with the assessment of the Centers for Disease Control and Prevention that an outbreak was “inevitable” in the United States, noting that the country had just 15 confirmed cases of COVID-19 and no deaths attributed to the virus. “When you have 15 people, and the 15 within a couple of days is going to be down to close to zero, that's a pretty good job we've done,” Trump said at the time. Ever since, Trump has been moving the goalposts on the pandemic, and on Sunday, with coronavirus cases and deaths mounting, Trump said that keeping the U.S. death toll between 100,000 and 200,000 would be “a very good job.”

  • One country is refusing to shut down to stop the coronavirus
    NBC News

    One country is refusing to shut down to stop the coronavirus

    While officials from Montreal to Moscow have placed populations under some form of lockdown designed to slow the spread of the coronavirus, one man continues to hold firm to the notion that the rest of the world has lost its mind: Belarusian President Alexander Lukashenko. “It is better to die on your feet than live on your knees!” Lukashenko told a Belarusian television reporter Saturday when asked whether the coronavirus could stop him from hitting the rink for a propaganda-filled hockey game. Lukashenko, one of the longest-serving leaders in the former Soviet Union, has been in power for over 25 years.

  • Egypt Could Deepen Rate Cuts to Combat Virus, Central Bank Governor Says
    Bloomberg

    Egypt Could Deepen Rate Cuts to Combat Virus, Central Bank Governor Says

    Egypt has scope to further cut interest rates to combat the impact of the coronavirus on an economy that's in good shape after sweeping reforms, the central bank governor said. Tarek Amer's comments came after the central bank on Sunday introduced temporary cash withdrawal restrictions, a step he said was necessary after customers took 30 billion pounds ($1.9 billion) from banks in the past three weeks. The measure, which could be revisited soon, seeks to encourage people to use bank transfers and e-payments.

  • Mexico's president defends his handshake with 'El Chapo' Guzman's mother — a 'respectable old lady'
    Business Insider

    Mexico's president defends his handshake with 'El Chapo' Guzman's mother — a 'respectable old lady'

    Mexican President Andres Manuel Lopez Obrador on Monday defended his weekend handshake with the mother of drug lord Joaquin "El Chapo" Guzman, calling her a "respectable old lady" and seeking to cast his critics as the principal menace to the country. In a 30-second video posted on Twitter on Sunday, Lopez Obrador could be seen approaching Maria Consuelo Loera's car, parked on a dirt road on the outskirts of Badiraguato, a mountainous municipality in the northwestern state of Sinaloa. Surrounded by onlookers, Lopez Obrador told Loera she need not get out of the car, they shook hands and after a brief exchange he told her he had "received her letter."

  • Fact check: will Covid-19 fade in the summer – then return later like the flu?
    The Guardian

    Fact check: will Covid-19 fade in the summer – then return later like the flu?

    Dr Marc Lipsitch: What makes seasonal viruses seasonal is a combination of opportunities for transmission – whether school is in term, which facilitates transmission – and what proportion of the population is immune, combined with weather. Humidity is lower in the winter, which is good for transmission. Low humidity makes [virus-carrying] droplets settle more slowly because they shrink to smaller sizes and then friction keeps them in the air, whereas high humidity doesn't do that.

  • A Doctor Who Met Putin Just Tested Positive, and Russia’s COVID-19 Crackdowns Could Get Real Ugly.
    The Daily Beast

    A Doctor Who Met Putin Just Tested Positive, and Russia’s COVID-19 Crackdowns Could Get Real Ugly.

    MOSCOW—Amid a growing uproar in newly locked-down Russia, news broke on Tuesday that a doctor President Vladimir Putin met with just a week ago during a highly publicized visit to a coronavirus treatment facility has now tested positive for the infection himself. Widely disseminated photos of the visit showed Putin donning an orange hazmat suit, but he had also talked to Dr. Denis Protsenko extensively without protection and photographs show them together with very little "social distancing." Putin's spokesman says the Russian president is tested frequently for coronavirus infection and is just fine.

  • Democratic lawmakers call for racial data in virus testing
    Associated Press

    Democratic lawmakers call for racial data in virus testing

    Democratic lawmakers are calling out an apparent lack of racial data that they say is needed to monitor and address disparities in the national response to the coronavirus outbreak. In a letter sent Friday to Health and Human Services Secretary Alex Azar, Sen. Elizabeth Warren and Rep. Ayanna Pressley, both from Massachusetts, said comprehensive demographic data on people who are tested or treated for the virus that causes COVID-19 does not exist. “Any attempt to contain COVID-19 in the United States will have to address its potential spread in low-income communities of color, first and foremost to protect the lives of people in those communities, but also to slow the spread of the virus in the country as a whole,” the lawmakers wrote to Azar.

  • 'The watermelons will rot:' U.S. visa confusion in Mexico keeps out agriculture workers
    Reuters

    'The watermelons will rot:' U.S. visa confusion in Mexico keeps out agriculture workers

    Restricted visa services, quickly evolving regulations and increased border controls risk wider labor shortages in the United States produce industry that may leave grocery stores scrambling for fruits and vegetables as spring and summer harvests spread across the United States. On Thursday, more than 100 workers waited in a stifling park in the center of Monterrey, Mexico, backpacks and rolling suitcases in hand, for news about their H-2A temporary agriculture worker visas.

  • IG Horowitz Found ‘Apparent Errors or Inadequately Supported Facts’ in Every Single FBI FISA Application He Reviewed
    National Review

    IG Horowitz Found ‘Apparent Errors or Inadequately Supported Facts’ in Every Single FBI FISA Application He Reviewed

    The Justice Department inspector general said it does “not have confidence” in the FBI's FISA application process following an audit that found the Bureau was not sufficiently transparent with the court in 29 applications from 2014 to 2019, all of which included “apparent errors or inadequately supported facts.” Inspector General Michael Horowitz released a report in December which found that the FBI included “at least 17 significant errors or omissions in the Carter Page FISA applications and many errors in the Woods Procedures” during its Crossfire Hurricane investigation of the 2016 Trump campaign.

  • Pelosi aims to move fast on next rescue package
    Politico

    Pelosi aims to move fast on next rescue package

    House Democrats are moving rapidly on ambitious plans for a fourth coronavirus relief package, with Speaker Nancy Pelosi eager to put her imprint on legislation that she says could be ready for a vote in the coming weeks. Pelosi told reporters Monday that Democrats are in the early stages of drafting another major bill that will not only shore up health systems and protect frontline health care workers but could include substantial investments in infrastructure. Our first bills were about addressing the emergency.

  • Israel's ultra-Orthodox Jews in fight over virus rules
    AFP

    Israel's ultra-Orthodox Jews in fight over virus rules

    Israeli police with face masks and batons and backed by surveillance helicopters have stepped up patrols of ultra-Orthodox Jewish neighbourhoods that have become coronavirus hotspots. This week has seen tense altercations, and some rabbis have admitted that their communities, where prayer and scripture study are traditionally communal, are not observing new social distancing regulations. A few days ago in Bnei Brak, a city near Tel Aviv with a largely ultra-Orthodox population, hundreds of faithful crowded together to attend the funeral of prominent rabbi Tzi Shenkar.

  • Bloomberg

    WHO Says Coronavirus Outbreak in Europe May Be Approaching Peak

    The World Health Organization said there are signs of some stabilization in Europe's coronavirus outbreak as the hardest-hit country in the region, Italy, reported the smallest number of new cases in almost two weeks. Mike Ryan, head of health emergencies at the WHO, said Monday that's “our fervent hope” Italy and Spain are approaching a peak, and that European lockdowns which started several weeks ago will start to bear fruit. New cases now reflect exposure to the disease about two weeks earlier, he said.

  • Largest U.S. dam removal sparks debate over coveted West water
    Yahoo News Video

    Largest U.S. dam removal sparks debate over coveted West water

    California's second-largest river has sustained Native American tribes with salmon for millennia, provided upstream farmers with irrigation water for generations and served as a haven for retirees who built homes along its banks.

  • The US passed a grim milestone with a single-day coronavirus death toll above 500, bringing the country's overall count past 3,000
    Business Insider

    The US passed a grim milestone with a single-day coronavirus death toll above 500, bringing the country's overall count past 3,000

    More than 3,000 people had died of the novel coronavirus in the US as of Monday night after a single-day death toll of more than 500. Previously, the highest death toll in 24 hours was 446 deaths, according to The Washington Post. The top US infectious-disease expert, Dr. Anthony Fauci, told CNN the country could see "millions of cases" as the outbreak pans out, with 100,000 to 200,000 deaths.

  • Mexico's president shifts tone on coronavirus, urges people to stay home, warns of dire consequences
    LA Times

    Mexico's president shifts tone on coronavirus, urges people to stay home, warns of dire consequences

    As the coronavirus pandemic spreads, Mexican President Andrés Manuel López Obrador has been criticized for what many called a lackadaisical posture — urging people to hug, shaking hands and kissing well-wishers as he stumped and extolling his personal talismans: Catholic scapulars, a shamrock and $2 bill. “Continue bringing the family to eat in restaurants,” López Obrador advised compatriots, arguing that such activity bolsters “the popular economy.” Although still avoiding curfews and mandatory stay-at-home orders, Mexican authorities are now abruptly citing a final chance to avert a national catastrophe that would inundate the country's limited healthcare infrastructure and probably result in many deaths.