Enlightenment Now

by Steven Pinker

  The very idea of climate engineering sounds like the crazed scheme of a mad scientist, and it once was close to taboo. Critics see it as a Promethean folly that could have unintended consequences such as disrupting rainfall patterns and damaging the ozone layer. Since the effects of any measure applied to the entire planet are uneven from place to place, climate engineering raises the question of whose hand should be on the world’s thermostat: as with a bickering couple, if one country lowered the temperature at the expense of another, it could set off a war. Once the world depended on climate engineering, then if for any reason it slacked off, temperatures in the carbon-soaked atmosphere would soar far more quickly than people could adapt. The mere mention of an escape hatch for the climate crisis creates a moral hazard, tempting countries to shirk their duty to reduce greenhouse gas emissions. And the accumulated CO2 in the atmosphere would continue to dissolve in seawater, slowly turning the oceans into carbonic acid.

  For all these reasons, no responsible person could maintain that we can just keep pumping carbon into the air and slather sunscreen onto the stratosphere to compensate. But in a 2013 book the physicist David Keith makes a case for a form of climate engineering that is moderate, responsive, and temporary. “Moderate” means that the amounts of sulfate or calcite would be just enough to reduce the rate of warming, not cancel it altogether; moderation is a virtue because small manipulations are less likely to bring unwelcome surprises. “Responsive” means that any manipulation would be careful, gradual, closely monitored, constantly adjusted, and, if indicated, halted altogether. And “temporary” means that the program would be designed only to give humanity breathing space until it eliminates greenhouse gas emissions and brings the CO2 in the atmosphere back to preindustrial levels. In response to the fear that the world would become addicted to climate engineering forever, Keith remarks, “Is it plausible that we will not figure out how to pull, say, five gigatons of carbon per year out of the air by 2075? I don’t buy it.”106

  Though Keith is among the world’s foremost climate engineers, he cannot be accused of being carried away by innovation thrill. A similarly thoughtful case may be found in the journalist Oliver Morton’s 2015 book The Planet Remade, which presents the historical, political, and moral dimensions of climate engineering alongside the technical state of the art. Morton shows that humanity has been disrupting global cycles of water, nitrogen, and carbon for more than a century, so it’s too late to preserve a primeval Earth system. And given the enormity of the climate change problem, it’s unwise to assume we will solve it quickly or easily. Research into how we might minimize the harm to millions of people before the solutions are completely in place only seems prudent, and Morton lays out scenarios of how a program of moderate and temporary climate engineering might be implemented even in a world that falls short of ideal global governance. The legal scholar Dan Kahan has shown that far from creating a moral hazard, providing information about climate engineering makes people more concerned about climate change and less biased by their political ideology.107

  * * *

  Despite a half-century of panic, humanity is not on an irrevocable path to ecological suicide. The fear of resource shortages is misconceived. So is the misanthropic environmentalism that sees modern humans as vile despoilers of a pristine planet. An enlightened environmentalism recognizes that humans need to use energy to lift themselves out of the poverty to which entropy and evolution consign them. It seeks the means to do so with the least harm to the planet and the living world. History suggests that this modern, pragmatic, and humanistic environmentalism can work. As the world gets richer and more tech-savvy, it dematerializes, decarbonizes, and densifies, sparing land and species. As people get richer and better educated, they care more about the environment, figure out ways to protect it, and are better able to pay the costs. Many parts of the environment are rebounding, emboldening us to deal with the admittedly severe problems that remain.

  First among them is the emission of greenhouse gases and the threat they pose of dangerous climate change. People sometimes ask me whether I think that humanity will rise to the challenge or whether we will sit back and let disaster unfold. For what it’s worth, I think we’ll rise to the challenge, but it’s vital to understand the nature of this optimism. The economist Paul Romer distinguishes between complacent optimism, the feeling of a child waiting for presents on Christmas morning, and conditional optimism, the feeling of a child who wants a treehouse and realizes that if he gets some wood and nails and persuades other kids to help him, he can build one.108 We cannot be complacently optimistic about climate change, but we can be conditionally optimistic. We have some practicable ways to prevent the harms and we have the means to learn more. Problems are solvable. That does not mean that they will solve themselves, but it does mean that we can solve them if we sustain the benevolent forces of modernity that have allowed us to solve problems so far, including societal prosperity, wisely regulated markets, international governance, and investments in science and technology.

  CHAPTER 11

  PEACE

  How deep do the currents of progress flow? Can they suddenly come to a halt or go into reverse? The history of violence provides an opportunity to confront these questions. In The Better Angels of Our Nature I showed that, as of the first decade of the 21st century, every objective measure of violence had been in decline. As I was writing it, reviewers warned me that it could all explode before the first copy hit the stores. (A war, possibly nuclear, between Iran and either Israel or the United States was the worry of the day.) Since the book was published in 2011, a cascade of bad news would seem to make it obsolete: civil war in Syria, atrocities in the Islamic State, terrorism in Western Europe, autocracy in Eastern Europe, shootings by police in the United States, and hate crimes and other outbursts of racism and misogyny from angry populists throughout the West.

  But the same Availability and Negativity biases that made people incredulous about the possibility that violence had declined can make them quick to conclude that any decline has been reversed. In the next five chapters I will put the recent bad news in perspective by going back to the data. I’ll plot the historical trajectories of several kinds of violence up to the present, including a reminder of the last data point available when The Better Angels of Our Nature went to press.1 Seven years or so is an eyeblink in history, but it offers a crude indication of whether the book capitalized on a lucky instant or identified an ongoing trend. More important, I’ll try to explain the trends in terms of deeper historical forces, placing them within the narrative of progress that is the subject of this book. (In doing so I’ll introduce some new ideas on what those forces are.) I’ll begin with the most extravagant form of violence, war.

  * * *

  For most of human history, war was the natural pastime of governments, peace a mere respite between wars.2 This can be seen in figure 11-1, which plots the proportion of time over the last half-millennium that the great powers of the day were at war. (Great powers are the handful of states and empires that can project force beyond their borders, that treat each other as peers, and that collectively control a majority of the world’s military resources.)3 Wars between great powers, which include world wars, are the most intense forms of destruction our sorry species has managed to dream up, and they are responsible for a majority of the victims of all wars combined. The graph shows that at the dawn of the modern era the great powers were pretty much always at war. But nowadays they are never at war: the last one pitted the United States against China in Korea more than sixty years ago.

  Figure 11-1: Great power war, 1500–2015

  Source: Levy & Thompson 2011, updated for the 21st century. Percentage of years the great powers fought each other in wars, aggregated over 25-year periods, except for 2000–2015. The arrow points to 1975–1999, the last quarter-century plotted in fig. 5–12 of Pinker 2011.

  The jagged decline of great power war conceals two trends tha
t until recently went in opposite directions.4 For 450 years, wars involving a great power became shorter and less frequent. But as their armies became better manned, trained, and armed, the wars that did take place became more lethal, culminating in the brief but stunningly destructive world wars. It was only after the second of these that all three measures of war—frequency, duration, and lethality—declined in tandem, and the world entered the period that has been called the Long Peace.

  It’s not just the great powers that have stopped fighting each other. War in the classic sense of an armed conflict between the uniformed armies of two nation-states appears to be obsolescent.5 There have been no more than three in any year since 1945, none in most years since 1989, and none since the American-led invasion of Iraq in 2003, the longest stretch without an interstate war since the end of World War II.6 Today, skirmishes between national armies kill dozens of people rather than the hundreds of thousands or millions who died in the all-out wars that nation-states have fought throughout history. The Long Peace has certainly been tested since 2011, such as in conflicts between Armenia and Azerbaijan, Russia and Ukraine, and the two Koreas, but in each case the belligerents backed down rather than escalating into all-out war. This doesn’t, of course, mean that escalation to major war is impossible, just that it is considered extraordinary, something that nations try to avoid at (almost) all costs.

  The geography of war also continues to shrink. In 2016 a peace agreement between the government of Colombia and Marxist FARC guerrillas ended the last active political armed conflict in the Western Hemisphere, and the last remnant of the Cold War. This is a momentous change from just decades before.7 In Guatemala, El Salvador, and Peru, as in Colombia, leftist guerrillas battled American-backed governments, and in Nicaragua it was the other way around (American-backed contras battling a left-wing government), in conflicts that collectively killed more than 650,000 people.8 The transition of an entire hemisphere to peace follows the path of other large regions of the world. Western Europe’s bloody centuries of warfare, culminating in the two world wars, have given way to more than seven decades of peace. In East Asia, the wars of the mid-20th century took millions of lives—in Japan’s conquests, the Chinese Civil War, and the wars in Korea and Vietnam. Yet despite serious political disputes, East and Southeast Asia today are almost entirely free from active interstate combat.

  The world’s wars are now concentrated almost exclusively in a zone stretching from Nigeria to Pakistan, an area containing less than a sixth of the world’s population. Those wars are civil wars, which the Uppsala Conflict Data Program (UCDP) defines as an armed conflict between a government and an organized force which verifiably kills at least a thousand soldiers and civilians a year. Here we find some recent cause for discouragement. A precipitous decline in the number of civil wars after the end of the Cold War—from fourteen in 1990 to four in 2007—went back up to eleven in 2014 and 2015 and to twelve in 2016.9 The flip is driven mainly by conflicts that have a radical Islamist group on one side (eight of the eleven in 2015, ten of the twelve in 2016); without them, there would have been no increase in the number of wars at all. Perhaps not coincidentally, two of the wars in 2014 and 2015 were fueled by another counter-Enlightenment ideology, Russian nationalism, which drove separatist forces, backed by Vladimir Putin, to battle the government of Ukraine in two of its provinces.

  The worst of the ongoing wars is in Syria, where the government of Bashar al-Assad has pulverized his country in an attempt to defeat a diverse set of rebel forces, Islamist and non-Islamist, with the assistance of Russia and Iran. The Syrian civil war, with 250,000 battle deaths as of 2016 (conservatively estimated), is responsible for most of the uptick in the global rate of war deaths shown in figure 11-2.10

  Figure 11-2: Battle deaths, 1946–2016

  Sources: Adapted from Human Security Report Project 2007. For 1946–1988: Peace Research Institute of Oslo Battle Deaths Dataset 1946–2008, Lacina & Gleditsch 2005. For 1989–2015: UCDP Battle-Related Deaths Dataset version 5.0, Uppsala Conflict Data Program 2017, Melander, Pettersson, & Themnér 2016, updated with information from Therese Pettersson and Sam Taub of UCDP. World population figures: 1950–2016, US Census Bureau; 1946–1949, McEvedy & Jones 1978, with adjustments. The arrow points to 2008, the last year plotted in fig. 6–2 of Pinker 2011.

  That uptick, however, comes at the end of a vertiginous six-decade plunge. World War II at its worst saw almost 300 battle deaths per 100,000 people per year; it is not shown in the graph because it would have scrunched the line for all subsequent years into a wrinkled carpet. In the postwar years, as the graph shows, the rate of deaths roller-coastered downward, cresting at 22 during the Korean War, 9 during the Vietnam War in the late 1960s and early 1970s, and 5 during the Iran-Iraq War in the mid-1980s, before bobbing along the floor at less than 0.5 between 2001 and 2011. It crept up to 1.5 in 2014 and subsided to 1.2 in 2016, the most recent year for which data are available.

  Followers of the news in the mid-2010s might have expected the Syrian carnage to have erased all of the historic progress of the preceding decades. That’s because they forget the many civil wars that ended without fanfare after 2009 (in Angola, Chad, India, Iran, Peru, and Sri Lanka) and also forget earlier ones with massive death tolls, such as the wars in Indochina (1946–54, 500,000 deaths), India (1946–48, a million deaths), China (1946–50, a million deaths), Sudan (1956–72, 500,000 deaths, and 1983–2002, a million deaths), Uganda (1971–78, 500,000 deaths), Ethiopia (1974–91, 750,000 deaths), Angola (1975–2002, a million deaths), and Mozambique (1981–92, 500,000 deaths).11

  Searing images of desperate refugees from the Syrian civil war, many of them struggling to resettle in Europe, have led to the claim that the world now has more refugees than at any time in history. But this is another symptom of historical amnesia and the Availability bias. The political scientist Joshua Goldstein notes that today’s four million Syrian refugees are outnumbered by the ten million displaced by the Bangladesh War of Independence in 1971, the fourteen million displaced by the partition of India in 1947, and the sixty million displaced by World War II in Europe alone, eras when the world’s population was a fraction of what it is now. Quantifying this misery is by no means callous to the terrible suffering of today’s victims. It honors the suffering of yesterday’s victims, and it ensures that policymakers will act in their interests by working from an accurate understanding of the world. In particular, it should prevent them from drawing dangerous conclusions about “a world at war,” which could tempt them to scrap global governance or return to a mythical “stability” of Cold War confrontation. “The world is not the problem,” Goldstein notes; “Syria is the problem. . . . The policies and practices that ended wars [elsewhere] can with effort and intelligence end wars today in South Sudan, Yemen, and perhaps even Syria.”12

  Mass killings of unarmed civilians, also known as genocides, democides, or one-sided violence, can be as lethal as wars and often overlap with them. According to the historians Frank Chalk and Kurt Jonassohn, “Genocide has been practiced in all regions of the world and during all periods in history.”13 During World War II, tens of millions of civilians were slaughtered by Hitler, Stalin, and imperial Japan, and in deliberate bombings of civilian areas by all sides (twice with nuclear weapons); at its peak the death rate was about 350 per 100,000 per year.14 But contrary to the assertion that “the world has learned nothing from the Holocaust,” the postwar period has seen nothing like the blood flood of the 1940s. Even within the postwar period, the rate of deaths in genocides has juddered down a steep sawtooth, as we see in two datasets shown in figure 11-3.

  Figure 11-3: Genocide deaths, 1956–2016

  Sources: PITF, 1955–2008: Political Instability Task Force State Failure Problem Set, 1955–2008, Marshall, Gurr, & Harff 2009; Center for Systemic Peace 2015. Calculations described in Pinker 2011, p. 338. UCDP, 1989–2016: UCDP One-Sided Violence Dataset v. 2.5-2016, Melander,
Pettersson, & Themnér 2016; Uppsala Conflict Data Program 2017, “High fatality” estimates, updated with data provided by Sam Taub of UCDP, scaled by world population figures from US Census Bureau. The arrow points to 2008, the last year plotted in fig. 6–8 of Pinker 2011.

  The peaks in the graph correspond to mass killings in the Indonesian anti-Communist “year of living dangerously” (1965–66, 700,000 deaths), the Chinese Cultural Revolution (1966–75, 600,000), Tutsis against Hutus in Burundi (1965–73, 140,000), the Bangladesh War of Independence (1971, 1.7 million), north-against-south violence in Sudan (1956–72, 500,000), Idi Amin’s regime in Uganda (1972–79, 150,000), Pol Pot’s regime in Cambodia (1975–79, 2.5 million), killings of political enemies in Vietnam (1965–75, 500,000), and more recent massacres in Bosnia (1992–95, 225,000), Rwanda (1994, 700,000), and Darfur (2003–8, 373,000).15 The barely perceptible swelling from 2014 to 2016 includes the atrocities that contribute to the impression that we are living in newly violent times: at least 4,500 Yazidis, Christians, and Shiite civilians killed by ISIS; 5,000 killed by Boko Haram in Nigeria, Cameroon, and Chad; and 1,750 killed by Muslim and Christian militias in the Central African Republic.16 One can never use the word “fortunately” in connection with the killing of innocents, but the numbers in the 21st century are a fraction of those in earlier decades.

  Of course, the numbers in a dataset cannot be interpreted as a direct readout of the underlying risk of war. The historical record is especially scanty when it comes to estimating any change in the likelihood of very rare but very destructive wars.17 To make sense of sparse data in a world whose history plays out only once, we need to supplement the numbers with knowledge about the generators of war, since, as the UNESCO motto notes, “Wars begin in the minds of men.” And indeed we find that the turn away from war consists in more than just a reduction in wars and war deaths; it also may be seen in nations’ preparations for war. The prevalence of conscription, the size of armed forces, and the level of global military spending as a percentage of GDP have all decreased in recent decades.18 Most important, there have been changes in the minds of men (and women).