To be sure, there are judicious climate change skeptics, sometimes called lukewarmers, who accept the mainstream science but accentuate the positive.49 They favor the fringe of the envelope of possibilities with the slowest temperature rise, note that the worst-case scenarios with runaway feedback are hypothetical, point out that moderately higher temperatures and CO2 have benefits in crop yields that should be traded off against their costs, and argue that if countries are allowed to get as rich as possible (without growth-sapping restrictions on fossil fuels) they will be better equipped to adapt to the climate change that does occur. But as the economist William Nordhaus points out, this is a rash gamble in what he calls the Climate Casino.50 If the status quo presents, say, an even chance that the world will get significantly worse, and a 5 percent chance that it will pass a tipping point and face a catastrophe, it would be prudent to take preventive action even if the catastrophic outcome is not certain, just as we buy fire extinguishers and insurance for our houses and don’t keep open cans of gasoline in our garages. Since dealing with climate change will be a multidecade effort, there’s plenty of time to back off if temperature, sea level, and ocean acidity happily stop rising.
Another response to climate change, from the far left, seems designed to vindicate the conspiracy theories of the far right. According to the “climate justice” movement popularized by the journalist Naomi Klein in her 2014 bestseller This Changes Everything: Capitalism vs. the Climate, we should not treat the threat of climate change as a challenge to prevent climate change. No, we should treat it as an opportunity to abolish free markets, restructure the global economy, and remake our political system.51 In one of the more surreal episodes in the history of environmental politics, Klein joined the infamous David and Charles Koch, the billionaire oil industrialists and bankrollers of climate change denial, in helping to defeat a 2016 Washington state ballot initiative that would have implemented the country’s first carbon tax, the policy measure which almost every analyst endorses as a prerequisite to dealing with climate change.52 Why? Because the measure was “right-wing friendly,” and it did not “make the polluters pay, and put their immoral profits to work repairing the damage they have knowingly created.” In a 2015 interview Klein even opposed analyzing climate change quantitatively:
We’re not going to win this as bean counters. We can’t beat the bean counters at their own game. We’re going to win this because this is an issue of values, human rights, right and wrong. We just have this brief period where we also have to have some nice stats that we can wield, but we shouldn’t lose sight of the fact that what actually moves people’s hearts are the arguments based on the value of life.53
Blowing off quantitative analysis as “bean-counting” is not just anti-intellectual but works against “values, human rights, right and wrong.” Someone who values human life will favor the policies that have the greatest chance of saving people from being displaced or starved while furnishing them with the means to live healthy and fulfilled lives.54 In a universe governed by the laws of nature rather than magic and deviltry, that requires “bean-counting.” Even when it comes to the purely rhetorical challenge of “moving people’s hearts,” efficacy matters: people are likelier to accept the fact of global warming when they are told that the problem is solvable by innovations in policy and technology than when they are given dire warnings about how awful it will be.55
Another common sentiment about how to prevent climate change is expressed in this letter, of a kind I receive every now and again:
Dear Professor Pinker
We need to do something about global warming. Why don’t the Nobel prize winning scientists sign a petition? Why don’t they tell the blunt truth, that the politicians are pigs who don’t care how many people get killed in floods and droughts?
Why don’t you and some friends start a movement on the Internet to get people to sign a pledge that they will make real sacrifices to fight global warming. Because that’s the problem. Nobody wants to make any sacrifices. People should pledge to never fly in airplanes except in dire emergencies, because airplanes burn so much fuel. People should pledge to eat no meat on at least three days per week, because meat production adds so much carbon to the atmosphere. People should pledge to buy no jewelry, ever, because refining gold and silver is so energy-intensive. We should abolish artistic pottery, because it burns so much carbon. The potters in university art departments are just going to have to accept the fact that we can’t go on like this.
Forgive the bean-counting, but even if everyone gave up their jewelry, it would not make a scratch in the world’s emission of greenhouse gases, which are dominated by heavy industry (29 percent), buildings (18 percent), transport (15 percent), land-use change (15 percent), and the energy needed to supply energy (13 percent). (Livestock is responsible for 5.5 percent, mostly methane rather than CO2, and aviation for 1.5 percent.)56 Of course my correspondent suggested forgoing jewelry and pottery not because of the effect but because of the sacrifice, and it’s no surprise that she singled out jewelry, the quintessential luxury. I bring up her ingenuous suggestion to illustrate two psychological impediments we face in dealing with climate change.
The first is cognitive. People have trouble thinking in scale: they don’t differentiate among actions that would reduce CO2 emissions by thousands of tons, millions of tons, and billions of tons.57 Nor do they distinguish among level, rate, acceleration, and higher-order derivatives—between actions that would affect the rate of increase in CO2 emissions, affect the rate of CO2 emissions, affect the level of CO2 in the atmosphere, and affect global temperatures (which will rise even if the level of CO2 remains constant). Only the last of these matters, but if one doesn’t think in scale and in orders of change, one can be satisfied with policies that accomplish nothing.
The other impediment is moralistic. As I mentioned in chapter 2, the human moral sense is not particularly moral; it encourages dehumanization (“politicians are pigs”) and punitive aggression (“make the polluters pay”). Also, by conflating profligacy with evil and asceticism with virtue, the moral sense can sanctify pointless displays of sacrifice.58 In many cultures people flaunt their righteousness with vows of fasting, chastity, self-abnegation, bonfires of the vanities, and animal (or sometimes human) sacrifice. Even in modern societies—according to studies I’ve done with the psychologists Jason Nemirow, Max Krasnow, and Rhea Howard—people esteem others according to how much time or money they forfeit in their altruistic acts rather than by how much good they accomplish.59
Much of the public chatter about mitigating climate change involves voluntary sacrifices like recycling, reducing food miles, unplugging chargers, and so on. (I myself have posed for posters in several of these campaigns led by Harvard students.)60 But however virtuous these displays may feel, they are a distraction from the gargantuan challenge facing us. The problem is that carbon emissions are a classic public goods game, also known as a Tragedy of the Commons. People benefit from everyone else’s sacrifices and suffer from their own, so everyone has an incentive to be a free rider and let everyone else make the sacrifice, and everyone suffers. A standard remedy for public goods dilemmas is a coercive authority that can punish free riders. But any government with the totalitarian power to abolish artistic pottery is unlikely to restrict that power to maximizing the common good. One can, alternatively, daydream that moral suasion is potent enough to induce everyone to make the necessary sacrifices. But while humans do have public sentiments, it’s unwise to let the fate of the planet hinge on the hope that billions of people will simultaneously volunteer to act against their interests. Most important, the sacrifice needed to bring carbon emissions down by half and then to zero is far greater than forgoing jewelry: it would require forgoing electricity, heating, cement, steel, paper, travel, and affordable food and clothing.
Climate justice warriors, indulging the fantasy that the developing world will do just that, advocate a regime of ??
?sustainable development.” As Shellenberger and Ted Nordhaus satirize it, that consists of “small co-ops in the Amazon forest where peasant farmers and Indians would pick nuts and berries to sell to Ben and Jerry’s for their ‘Rainforest Crunch’ flavor.”61 They would be allowed solar panels that could light an LED or charge a cell phone, but nothing more. Needless to say, the people who actually live in those countries have a different idea. Escaping from poverty requires abundant energy. The proprietor of HumanProgress, Marian Tupy, points out that in 1962 Botswana and Burundi were equally destitute, with an annual per capita income of $70, and neither emitted much CO2. By 2010, Botswanans earned $7,650 a year, 32 times as much as the still-poor Burundians, and they emitted 89 times as much CO2.62
Faced with such facts, climate justice warriors reply that rather than enriching poor nations, we should impoverish rich ones, switching back, for example, to “labor-intensive agriculture” (to which an appropriate reply is: You first). Shellenberger and Nordhaus note how far progressive politics has moved from the days in which rural electrification and economic development were among its signature projects: “In the name of democracy it now offers the global poor not what they want—cheap electricity—but more of what they don’t want, namely intermittent and expensive power.”63
Economic progress is an imperative in rich and poor countries alike precisely because it will be needed to adapt to the climate change that does occur. Thanks in good part to prosperity, humanity has been getting healthier (chapters 5 and 6), better fed (chapter 7), more peaceful (chapter 11), and better protected from natural hazards and disasters (chapter 12). These advances have made humanity more resilient to natural and human-made threats: disease outbreaks don’t become pandemics, crop failures in one region are alleviated by surpluses in another, local skirmishes are defused before they erupt into war, populations are better protected against storms, floods, and droughts. Part of our response to climate change must be to ensure that these gains in resilience continue to outpace the threats that a warming planet will throw at it. Every year that developing countries get richer, they will have more resources for building seawalls and reservoirs, improving public health services, and moving people away from rising seas. For that reason they must not be kept in energy poverty—but neither does it make sense for them to raise incomes with massive coal burning that will overwhelm everyone later with weather disasters.64
* * *
How, then, should we deal with climate change? Deal with it we must. I agree with Pope Francis and the climate justice warriors that preventing climate change is a moral issue because it has the potential to harm billions, particularly the world’s poor. But morality is different from moralizing, and is often poorly served by it. (The Pope’s encyclical backfired, decreasing concern about climate change among the conservative Catholics who were aware of it.)65 It may be satisfying to demonize the fossil fuel corporations that sell us the energy we want, or to signal our virtue by making conspicuous sacrifices, but these indulgences won’t prevent destructive climate change.
The enlightened response to climate change is to figure out how to get the most energy with the least emission of greenhouse gases. There is, to be sure, a tragic view of modernity in which this is impossible: industrial society, powered by flaming carbon, contains the fuel of its own destruction. But the tragic view is incorrect. Ausubel notes that the modern world has been progressively decarbonizing.
The hydrocarbons in the stuff we burn are composed of hydrogen and carbon, which release energy as they combine with oxygen to form H2O and CO2. The oldest hydrocarbon fuel, dry wood, has a ratio of combustible carbon atoms to hydrogen atoms of about 10 to 1.66 The coal which replaced it during the Industrial Revolution has an average carbon-to-hydrogen ratio of 2 to 1.67 A petroleum fuel such as kerosene may have a ratio of 1 to 2. Natural gas is composed mainly of methane, whose chemical formula is CH4, with a ratio of 1 to 4.68 So as the industrial world climbed an energy ladder from wood to coal to oil to gas (the last transition accelerated in the 21st century by the abundance of shale gas from fracking), the ratio of carbon to hydrogen in its energy source steadily fell, and so did the amount of carbon that had to be burned to release a unit of energy (from 30 kg of carbon per gigajoule in 1850 to about 15 today).69 Figure 10-7 shows that carbon emissions follow a Kuznets arc: when rich countries such as the United States and the United Kingdom first industrialized, they emitted more and more CO2 to produce a dollar of GDP, but they turned a corner in the 1950s and since then have been emitting less and less. China and India are following suit, cresting in the late 1970s and mid-1990s, respectively. (China flew off the charts in the late 1950s because of Mao’s boneheaded schemes like backyard iron smelters with copious emissions and zero economic output.) Carbon intensity for the world as a whole has been declining for half a century.70
Figure 10-7: Carbon intensity (CO2 emissions per dollar of GDP), 1820–2014
Source: Ritchie & Roser 2017, based on data from the Carbon Dioxide Information Analysis Center, http://cdiac.ornl.gov/trends/emis/tre_coun.html. GDP is in 2011 international dollars; for the years before 1990, GDP comes from Maddison Project 2014.
Decarbonization is a natural consequence of people’s preferences. “Carbon blackens miners’ lungs, endangers urban air, and threatens climate change,” Ausubel explains. “Hydrogen is as innocent as an element can be, ending combustion as water.”71 People want their energy dense and clean, and as they move into cities, they accept only electricity and gas, delivered right to their bedside and stovetop. Remarkably, this natural development has brought the world to Peak Coal and maybe even Peak Carbon. As figure 10-8 shows, global emissions plateaued from 2014 to 2015 and declined among the top three emitters, namely China, the European Union, and the United States. (As we saw for the United States in figure 10-3, carbon emissions plateaued while prosperity rose: between 2014 and 2016, the Gross World Product grew by 3 percent annually.)72 Some of the carbon was reduced by the growth of wind and solar power, but most of it, particularly in the United States, was reduced by the replacement of C137H97O9NS coal with CH4 gas.
Figure 10-8: CO2 emissions, 1960–2015
Sources: Our World in Data, Ritchie & Roser 2017 and https://ourworldindata.org/grapher/annual-co2-emissions-by-region, based on data from the Carbon Dioxide Information Analysis Center, http://cdiac.ornl.gov/CO2_Emission/, and Le Quéré et al. 2016. “International air & sea” refers to aviation and sea transport; it corresponds to “Bunker fuels” in the original sources. “Other” refers to the difference between estimated global CO2 emissions and the sum of the regional and national totals; it corresponds to the “Statistical difference” component.
The long sweep of decarbonization shows that economic growth is not synonymous with burning carbon. Some optimists believe that if the trend is allowed to evolve into its next phase—from low-carbon natural gas to zero-carbon nuclear energy, a process abbreviated as “N2N”—the climate will have a soft landing. But only the sunniest believe this will happen by itself. Annual CO2 emissions may have leveled off for the time being at around 36 billion tons, but that’s still a lot of CO2 added to the atmosphere every year, and there is no sign of the precipitous plunge we would need to stave off the harmful outcomes. Instead, decarbonization needs to be helped along with pushes from policy and technology, an idea called deep decarbonization.73
It begins with carbon pricing: charging people and companies for the damage they do when they dump their carbon into the atmosphere, either as a tax on carbon or as a national cap with tradeable credits. Economists across the political spectrum endorse carbon pricing because it combines the unique advantages of governments and markets.74 No one owns the atmosphere, so people (and companies) have no reason to stint on emissions that allow each of them to enjoy their energy while harming everyone else, a perverse outcome that economists call a negative externality (another name for the collective costs in a public goods game, or the da
mage to the commons in the Tragedy of the Commons). A carbon tax, which only governments can impose, “internalizes” the public costs, forcing people to factor the harm into every carbon-emitting decision they make. Having billions of people decide how best to conserve, given their values and the information conveyed by prices, is bound to be more efficient and humane than having government analysts try to divine the optimal mixture from their desks. The potters don’t have to hide their kilns from the Carbon Police; they can do their part in saving the planet by taking shorter showers, forgoing Sunday drives, and switching from beef to eggplant. Parents don’t have to calculate whether diaper services, with their trucks and laundries, emit more carbon than the makers of disposable diapers; the difference will be folded into the prices, and each company has an incentive to lower its emissions to compete with the other. Inventors and entrepreneurs can take risks on carbon-free energy sources that would compete against fossil fuels on a level playing field rather than the tilted one we have now, in which the fossils get to spew their waste into the atmosphere for free. Without carbon pricing, fossil fuels—which are uniquely abundant, portable, and energy-dense—have too great an advantage over the alternatives.
Carbon taxes, to be sure, hit the poor in a way that concerns the left, and they transfer money from the private to the public sector in a way that annoys the right. But these effects can be neutralized by adjusting sales, payroll, income, and other taxes and transfers. (As Al Gore put it: Tax what you burn, not what you earn.) And if the tax starts low and increases steeply and predictably over time, people can factor the increase into their long-term purchases and investments, and by favoring low-carbon technologies as they evolve, escape most of the tax altogether.75