The Sunniest Climate-Change Story You’ve Ever Read This is the year humans finally got serious about saving themselves from themselves.

Photographs by Ralph Smith

Here on planet Earth, things could be going better. The rise in atmospheric temperatures from greenhouse gases poses the most dire threat to humanity, measured on a scale of potential suffering, since Imperial Japan and Nazi Germany launched near-simultaneous wars of conquest. And the problem has turned out to be much harder to solve. It’s not the money. The cost of transitioning away from fossil fuels, measured as a share of the economy, may amount to a fraction of the cost of defeating the Axis powers. Rather, it is the politics that have proved so fiendish. Fighting a war is relatively straightforward: You spend all the money you can to build a giant military and send it off to do battle. Climate change is a problem that politics is almost designed not to solve. Its costs lie mostly in the distant future, whereas politics is built to respond to immediate conditions. (And of the wonders the internet has brought us, a lengthening of mental time horizons is not among them.) Its solution requires coordination not of a handful of allies but of scores of countries with wildly disparate economies and political structures. There has not yet been a galvanizing Pearl Harbor moment, when the urgency of action becomes instantly clear and isolationists melt away. Instead, it breeds counterproductive mental reactions: denial, fatalism, and depression.

This fall, as world leaders prepare to gather in Paris for the United Nations climate-change conference in December and bureaucrats bureaucratize, onlookers could be excused for treating the whole affair with weariness. As early as the 19th century, scientists had observed that the release of carbon dioxide into the atmosphere trapped heat that would otherwise have escaped into outer space. It took until 1997 for the U.N. to draw up a rough deal, in Kyoto, Japan, designed to arrest what was by then obviously a crisis. The agreement failed on the international stage, which didn’t stop the Republicans in the U.S. Senate, who hoped to use the treaty as fodder for attack ads, from bringing the moribund issue up for a vote — where it failed again, 95-0.

It was another decade until the next major attempt to coordinate international action, in Copenhagen, Denmark. That failed too. Then, in 2010, President Obama, temporarily enjoying swollen Democratic majorities in both houses, tried to pass a cap-and-trade law that would bring the U.S. into compliance with the reductions it had pledged in Copenhagen. A handful of Democrats from fossil-fuel states joined with nearly every Republican to filibuster it.

In the intervening years, the crisis has become rapidly less theoretical, as mountain snows have permanently disappeared, jungles have been burned for cropland, ice sheets have crumbled. Rather than galvanizing action, this merely depressed us. This July, as the planet endured its hottest month in recorded history, the former NASA climate scientist James Hansen revised his predictions and issued preliminary conclusions that, while controversial among other scientists, were terrifying: Sea levels might be rising three times faster than estimated, and within a few decades, “forced migrations and economic collapse might make the planet ungovernable, threatening the fabric of civilization.” The philosopher Dale Jamieson has a recent book titled Reason in a Dark Time: Why the Struggle Against Climate Change Failed — And What It Means for Our Future. Jonathan Franzen recently wrote an ostentatiously morbid essay in The New Yorker positing that “drastic planetary overheating is a done deal.” The drama has taken on an air of inevitability, of a tragedy at the outset of its final scene — the tension so unbearable, and the weight of looming catastrophe so soul-crushing, that some people seek the release of final defeat rather than endless struggle in the face of hopeless odds. Working for change, or even hoping for it, has felt like a sucker’s game. It is hard even to conceive of good global-warming news when bad news is the only kind that has ever existed.

But guess what everyone’s been missing in the middle of their keening for the dear, soon-to-be-departed Earth? There is good news. And not just incremental good news but transformational good news, developments that have the potential to mitigate the worst effects of climate change to a degree many had feared impossible. Those who have consigned the world to its doom should reconsider. The technological and political underpinnings are at last in place to actually consummate the first global pact to limit greenhouse-gas emissions. The world is suddenly responding to the climate emergency with — by the standards of its previous behavior — astonishing speed. The game is not over. And the good guys are starting to win.

Photo: Ralph Smith

For human to wean ourselves off carbon-emitting fossil fuel, we will have to use some combination of edict and invention — there is no other plausible way around it. The task before the world is best envisioned not as a singular event but as two distinct but interrelated revolutions, one in political willpower and the other in technological innovation. It has taken a long time for each to materialize, in part because the absence of one has compounded the difficulty of the other. It is extremely hard to force a shift to clean energy when dirty energy is much cheaper, and it is extremely hard to achieve economies of scale in new energy technologies when the political system has not yet nudged you to do so.

And yet, if you formed a viewpoint about the cost effectiveness of green energy a generation ago (when, for instance, Ronald Reagan tore the costly solar panels installed by his predecessor off the White House roof), or even just a few years ago, your beliefs are out of date. That technological revolution is well under way.

For one thing, the price of solar is falling, and rapidly. In a March 2011 post for Scientific American’s website, Ramez Naam, a computer scientist and technological enthusiast, compared the rapid progress of solar power to Moore’s Law, the famous dictum that described the process by which microchips grew steadily more useful over time, doubling in efficiency every two years. The price of solar power had fallen in two decades from nearly $10 a watt to about $3. By 2030, he predicted, the price could drop to just 50 cents a watt.

Four years later, in the spring of this year, Naam revisited his post and admitted his prediction had been wrong. It was far too conservative. The price of solar power had already hit the 50-cent threshold. In the sunniest locations in the world, building a new solar-power plant now costs less than coal or natural gas, even without subsidies, and within six years, this will be true of places with average sunlight, too. Taller turbines, with longer and more powerful blades, have made wind power competitive in a growing swath of the country (the windy parts). By 2023, new wind power is expected to cost less than new power plants burning natural gas.

Meanwhile, the coal industry has gone into free fall. In 2009, 523 coal plants operated in the United States. More than 200 of them have since shut down, displaced mostly by natural-gas plants, which emit half as much carbon dioxide. (The most common process of drilling for gas, fracking, does release methane, a super-powerful greenhouse gas, but the Obama administration’s just-released regulation will address those leaks for the first time.) Only one coal-fired plant has been green-lit since 2008, and new regulations make it virtually certain that no coal plant will break ground in the United States ever again.

The energy revolution has rippled widely through the economy. In the first half of this year, renewable-energy installations accounted for 70 percent of new electrical power. As the energy mix has grown cleaner, people have found ways to use less of it, too. Incandescent bulbs have been replaced with efficient LEDs, in what Prajit Ghosh, director of power and renewables research at energy company Wood Mackenzie, refers to as a “total bulb revolution.” Tesla has introduced a new home battery, the “Powerwall,” and broken ground on a plant in Nevada, called the Gigafactory, with the capacity to churn out 500,000 lithium-ion battery packs per year, which will allow it to cut battery costs by a third and sell less expensive electric cars. And these are only today’s technologies. Laboratories from Cambridge to Silicon Valley are racing to develop next-generation batteries, as well as ultra­efficient solar cells, vehicles, kitchen appliances. For more than a century, everything that consumed energy was designed without a thought to the carbon dioxide that would be released into the air. Now everything from buildings to refrigerators is being designed anew to account for scientific reality.

This is a story of ingenuity, but it is not, as Jeb Bush has suggested, thanks simply to “a person in a garage somewhere that’s going to come up with a disruptive technology that’s going to solve these problems.” The energy market has been disrupted because governments disrupted it; progress came not in spite of our government but because of it. The private sector developed LED bulbs because Washington required higher-efficiency lighting. The post-crash stimulus package pumped $90 billion into green-energy subsidies, as China and Germany made similar public investments. The Obama administration churned out regulations forcing higher energy standards on the automobile industry, buildings, agriculture, and oil and drilling. Its Clean Power Plan, which will require for the first time that states reduce emissions from their power plants, is the capstone of the first major response to climate change in American history.

This full-court press was Obama’s goal in 2009, when he tried to persuade Congress to pass a law creating a cap-and-trade market for carbon. After the bill failed the following year, environmentalists sank into despair — where many of them have stayed slumped ever since, having decided the battle is lost. When the first signs emerged, shortly after the 2012 election, that the Obama administration might use its regulatory authority to limit power-plant emissions, dejected liberals waved away the prospect as a fairy tale. Now it is a fait accompli, and the main argument environmentalists make to dismiss Obama’s climate plan is not that he will never have the guts to do it but that it merely ratifies a clean-energy revolution driven by market forces. The overall direction of American carbon use is no longer in doubt. American carbon emissions peaked in 2007 and have fallen since, with the main question now being how far and fast they will plummet.

Conservatives tend to dismiss efforts to limit American greenhouse-gas emissions by pointing out that global warming, if it exists at all, is an international problem rather than an American one. Reducing emissions in the U.S. alone can barely budge global temperatures. This is factually correct. The U.S. once led the world in greenhouse-gas emissions but has long since been overtaken by China, which now emits twice as much total carbon. The mistake the conservatives have made lies in their assumption that American policy has no bearing upon Chinese policy. The two have turned out to be closely linked. China, in fact, has undergone an energy revolution far more rapid than anything under way in the U.S. — the country that supposedly couldn’t be shamed into action has, instead, shamed us. As a result, the scale and pace of the change are almost incomprehensible.

The reversal happened quickly. As China has industrialized, it’s followed the same path of cheap, dirty energy that the U.S. and Europe had blazed a century before. Over the past quarter-century, Chinese emissions quadrupled. Lifting the oppressive burden of poverty from China’s people required huge quantities of carbon, and the process had no end in sight. As recently as 2009, analysts believed China’s carbon-emissions level would continue to rise, not reaching its peak until 2050.

The development of a vast new source of global warming in the East, just as the West was making a dent in its emissions, provided the single largest reason for the feeling of helplessness that has pervaded environmentalism. Worse, most of the developing world longed to replicate China’s astonishing new prosperity. The Chinese model suggested that horrific poverty could be escaped only at a horrific global cost. It is hardly selfish for developing countries to refuse to force their impoverished people to shoulder the burden of averting climate change. (Even now, China burns less than half as much carbon per person than does the U.S.) The developing world has thus been presented with a brutal moral logic: The rich countries have burned through the world’s carbon budget, and there is almost nothing left.

But in the past year, something amazing has taken place. In 2014, China’s coal production and its consumption both fell, and the drop appears to be continuing, or even accelerating, this year. Derek Scissors, a China analyst at the American Enterprise Institute, who had previously believed Chinese coal use would rebound, conceded his error and called the shocking reversal “an economic and social sea change.” China’s coal use has made the air in its largest cities intolerable, and Communist Party elites have to breathe the same air as everybody else. The regime’s long-standing desire to fix its air pollution has been well known, but that desire has only now translated into results.

China has made colossal investments in green energy. It plans to increase its solar-energy capacity this year alone by 18 gigawatts — as much solar-energy capacity as exists in the U.S. right now. Its wind-energy production has increased tenfold in a half-dozen years, and the country is in the midst of what one analyst called “the largest build-out of hydroelectricity the world has ever seen.” Last fall, in a bilateral agreement with the U.S., China promised its carbon-dioxide emissions would peak in 2030 — two decades earlier than recently believed. And at the current rate of transformation, this promise appears conservative. China is widely expected to move its peak-emissions date up to 2025 by the Paris conference.

When the Chinese government announced its participation in the bilateral agreement, American conservatives rolled their eyes. Their skepticism that China would curtail its emissions rested upon the premise that maintaining its prosperity required it to burn ever-increasing amounts of dirty energy, forever. “China almost certainly won’t take significant steps to reduce carbon emission,” explained National Review. “That’s because the legitimacy of the Chinese Communist party’s government rests squarely on economic development. Energy — often produced by dirty coal — allows that economic development to occur, lifting millions out of hand-to-mouth poverty.” This analysis relied upon a fatally flawed assumption: that producing more energy required producing more carbon emissions. China is finding ways to produce more energy with less carbon. The ratio of carbon emissions to energy produced is called “carbon intensity,” and China’s carbon-intensity ratio has dropped precipitously. In 2009, China promised to reduce its carbon intensity by 45 percent from its 2005 level by 2020. It is well on track to achieve this (it’s already down 34 percent), and is now promising to deepen the cut to 60 or 65 percent — evidence that China has begun thinking seriously and practically about what it will mean to steward the majority of the world’s future population.

The energy revolution in China has laid the groundwork for a future scarcely anybody could have imagined just a few years ago. For most of the 1.3 billion people globally without access to electricity, building new solar power is already cheaper than fossil-fuel generation. And so, the possibility has come into view that, just as the developing world is skipping landlines and moving straight into cellular communication, it will forgo the dirty-energy path and follow a clean one. The global poor can create a future of economic growth for themselves without burning the world.

That is the achievable — truly achievable! — task now before the world as its leaders gather in Paris. For the first time, countries are negotiating an agreement while both revolutions, political and technological, are under way and mutually reinforcing. The plummeting financial cost of renewable energy has decreased the political cost for leaders of the developing world. And the agreement between the U.S. and China — the respective leaders of the developed and the developing worlds — has set a template whose particulars can be strengthened over time.

In advance of the conference, the outlines of a rough global consensus have come into view. Brazil has pledged to ramp up its renewable-energy production and to prevent further destruction of its rain forests, which help trap carbon. South Korea has promised a 37 percent cut in its emissions by 2030. India, a poorer country than China that emits one-tenth as much carbon per person as the U.S., has not yet committed to a firm date when its carbon emissions will peak. But it quintupled its target for installing new solar power, and its political leaders have embraced progressive climate views.

The West has responded in kind. The European Union has pledged to cut 40 percent (from its 1990 level). Pope Francis’s public embrace of climate change as a life-or-death issue has affirmed its place as a shared global vision. No government in the world has challenged either the existence of anthropogenic global warming or the urgent need to bring the world together to halt it. And Obama’s increasingly visible crusading for action, including his recent trip to Alaska, is the action of a president who realizes his legacy could not be rescued from a failure in Paris and who has the conviction that failure cannot and will not happen. Almost one century ago, a conference in Paris (Versailles, actually) doomed the world to its darkest moment. The stage is now set for a conference in Paris that will alter the course of human history for the better.

Photo: Ralph Smith

If this sounds surprisingly optimistic, that may be because you reside in a highly peculiar place: the United States of America. If there is a single vantage point from which the new global consensus on climate change is least evident, other than perhaps Saudi Arabia, it is the U.S. In a survey last year of 20 countries, the U.S. had the highest proportion of citizens who disagree that climate change is the result of human activity. And that is not because the U.S. is especially abundant in fossil fuels, or unusually removed from the effects of a changing climate, but because one of our two major parties is completely sui generis. From 2001 to 2010, a period when the scientific community grew more certain that heat-trapping gases were warming the atmosphere, the proportion of Republicans who believe the effects of climate change had already set in actually declined from 50 percent to 30 percent.

The unique quality of the Republican Party’s climate doctrine can be found not in its Donald Trumps and its Ted Cruzes but in their putatively sane competitors in the 2016 presidential primary. “I do not believe that human activity is causing these dramatic changes to our climate the way these scientists are portraying it,” said Marco Rubio last year. A spokesman for Scott Walker asserted recently that the governor “believes facts have shown that there has not been any measurable warming in the last 15 or 20 years.” Even John Kasich, who has carved a niche on the far-left wing of his party’s presidential field for refusing to boycott the Medicaid expansion in Obamacare, has dismissed the scientific consensus as “some theory that’s not proven.” Jeb Bush has tried to dodge. “I’m a skeptic. I’m not a scientist. I think the science has been politicized,” he scoffed in 2009. His view has since hardened. “For the people to say the science is decided on this is really arrogant,” he asserted earlier this year.

And the tenor of Republican thinking below the level of presidential candidates is cruder still. Dana Rohrabacher, a member of the House Committee on Science and Technology, has claimed “global warming is a total fraud.” Lamar Smith, the chairman of that committee, has mocked the “malfunctioning climate models” designed by “climate alarmists.” James Inhofe, chairman of the Senate Committee on Environment and Public Works, is the author of a 2012 book titled The Greatest Hoax: How the Global Warming Conspiracy Threatens Your Future. Conservative states have refused to entertain plans for the inevitable disappearance of their coastlines; some have even banned the use of the term “climate change.” Prestigious intellectuals in the conservative movement, like George Will, preach conspiratorial pseudoscientific theories.

The U.S. is the only democracy in which such a consensus can be found. (Even the conservative ruling party in coal-rich Australia is submitting proposals to reduce its carbon emissions.) Eileen Claussen, former president of the Pew Center on Global Climate Change, told National Journal that, while some individuals in other countries question climate science, there is “no party-wide view like this anywhere in the world that I am aware of.” The Republican Party’s complete refusal to accept any limits on greenhouse-gas emissions whatsoever is an unspoken force shaping the Paris negotiations. The outcome cannot be written as a formal treaty, since treaties require approval by the Senate, and Senate approval requires Republicans. Instead, the agreement will take the form of legally nonbinding pledges, which the U.N. is calling “intended nationally determined contributions,” enforced by international diplomatic pressure. The entire world is, in essence, tiptoeing gingerly around the unhinged second-largest political party in the world’s second-largest greenhouse-gas emitter, in hopes of saving the world behind its back.

Of course, it is unfortunate for the future of mankind that climate-change denialism has surfaced as a regional quirk in the most powerful country on Earth. The fossil-fuel industry has invested heavily in U.S. politics and can surely take some credit for the Republican Party’s positions, but conservative resentment of climate science is more deeply rooted and pathological than economic influence can fully explain. Conservative distrust of the scientific community has steadily increased over the last four decades. Even as the coal industry has collapsed, and American solar firms now employ twice as many people, the Republican affiliation with coal as a cherished way of life has deepened. Conservatives’ association of science with the liberal agenda has hardened Republican resolve to do nothing to limit climate change, which has, in turn, deepened the association of science with the liberal agenda. Increasing evidence of climate change does not halt this vicious cycle. It may actually accelerate it by fomenting resentment. An alarming social study from June found that climate skeptics who read reports about natural disasters were less likely to favor helping the victims if the story connected the disaster to climate change.

The Republican view that climate change is uncertain, overblown, or nonexistent has run alongside a long-standing skepticism about international diplomacy. Conservatives treat the prospect of a global agreement to limit emissions as not merely a challenge (which it is) but a conceptual impossibility. The presumed impossibility of getting other countries in general, and China in particular, to cut back on greenhouse gases featured heavily in Republican denunciations of cap and trade during Obama’s first two years. They have greeted China’s agreement to do this very thing with scorn. When Obama negotiated his bilateral pledge with China last year, conservatives howled, predicting disaster. But they were unable to thwart the deal, and now they dismiss China’s emissions pledges as too easy to fulfill. (Senate Majority Leader Mitch McConnell scoffed that last November’s deal “requires the Chinese to do nothing at all for 16 years.”) Or else, too difficult. (“China’s commitment to reduce carbon emissions is unattainable and unrealistic,” wrote Inhofe.) Or they have simply carried on as if China had made no changes to its behavior at all. (Marco Rubio, this summer: “As far as I can see, China and India and other developing countries are going to continue to burn anything they can get their hands on.”)

Republicans have set out to induce the result they predict, warning foreign leaders that Obama will not be able to carry out his promises. After Obama formally submitted the U.S.’s proposed emission reductions to the United Nations, McConnell drafted a letter urging the world not to believe him. “Considering that two-thirds of the U.S. federal government hasn’t even signed off on the Clean Power Plan and 13 states have already pledged to fight it,” he wrote, “our international partners should proceed with caution before entering into a binding, unattainable deal.” This was an American official warning other countries to “proceed with caution” before negotiating with the U.S.

The Republican plan to destroy the global climate accord involves domestic sabotage as well. The congressional wing will attach to budget bills to fund the government new rules forbidding the EPA from carrying out its regulations. (Obama will veto any such bills, making them a futile symbolic gesture.) Conservatives have also filed suit to block the EPA’s regulations, a somewhat more dangerous possibility, but — given that the Supreme Court has already ordered the White House to regulate carbon — not likely to inflict fatal damage.

By far the most effective weapon at the GOP’s disposal is its prospect of winning the 2016 election. Jeffrey Holmstead, formerly the chief air regulator at the EPA under the Bush administration and now an energy lobbyist, boasts, “Any Republican candidate that I can imagine would very quickly just rescind the Clean Power Plan.” Jeb Bush has called it “irresponsible” and “overreaching”; Rubio called it “catastrophic.” They are the relative moderates on the issue — Scott Walker has not only rejected the plan but also promised to eliminate all federal regulation of the environment, except for a small handful of intrastate disputes.

And so the world is racing to decarbonize before the Republican Party — as constituted in its current, delirious form — can regain power over the U.S. With the GOP as unpopular as ever, the rest of the planet has a tenuous upper hand. At some point, perhaps only a few years from now, decarbonization will have gained irreversible momentum, strengthening the economic power of the green-energy lobby and weakening the power of the fossil-fuel lobby. And maybe, eventually, the Republican Party will give up its affinity for unlimited carbon emissions, just as it is surrendering on gay marriage. In the meantime, the 2016 election threatens to ruin the new global consensus on climate change. The concentration of American climate policy in the Executive branch, the GOP’s descent into madness, and the sudden attainability of international cooperation have all raised the planetary stakes of the presidential election beyond anything in previous experience.

If the Paris talks succeed, will the world have acted fully and promptly to limit climate change before it’s too late? The atmosphere has already warmed by one degree Celsius since the end of the 19th century. Climate change has already begun. Even if the world could eliminate all fossil-fuel use tomorrow, the amount of carbon already in the atmosphere will create, and is already creating, disruption, havoc, and death. Even if the world halted all greenhouse-gas emissions today, it would be, by the standard of perfection, too late.

Besides, the target the world has set for measuring success — holding increased global temperature to no more than two degrees Celsius — is merely a guess at salvation. Exactly how much carbon dioxide can we pump into the air and stay under two degrees? Scientists estimate that figure is 450 parts per million, but that is only an estimate; 450 parts per million could produce less warming or more.

And is under two degrees the safety zone? That is also a guess, and it’s an even less precise one. Projecting how human life would change in a world of two-degree warming imagines a vast and complex calculation of natural events that can be predicted hazily: heat waves, drought, animal-species extinctions, and extreme weather. Then you have possible human responses that can only be guessed at wildly, like an increase in refugees, political instability, resource wars. Climate change is not a risk like the danger of wandering up to the edge of a cliff in the darkness, where you either remain safe or plunge to your demise. A rise of 1.9 degrees does not mean salvation, and 2.1 degrees does not mean doom. It is a problem of gradations of suffering and expense — but remaining on the lowest possible point on that terrifying, unknowable scale is a question literally of life or death.

Yet misleading metaphors have dominated our thinking about the problem. Is it too late? Have we reached a point of no return? All-or-nothing thinking can be a useful tool for communicating urgency to the public, just as one would communicate the urgency of a war or a clarifying indication of political commitment. But it has also become a trap into which many of us — especially environmentalists — have fallen. In truth, the fight to save the Earth from climate change is not something that will be “won” or “lost.” Climate change is a problem of risk management, albeit on a planetary scope.

The most pressing danger is not the likely scenario of what unabated emissions would do — which is bad enough — but the less likely, yet far from impossible, versions, if it turns out that a given level of atmospheric carbon produces more warming than scientists estimate. Unabated, greenhouse-gas emissions could easily produce a much higher spike than forecast. Warmer temperatures might create new effects of their own, like the melting of the permafrost in the Siberian tundra, releasing vast stores of carbon and creating still more heat. The predictions of what happens if humanity cooks the planet entail high levels of uncertainty. Scientists guess that failing to control emissions poses about a 10 percent chance of creating a rise in global temperatures that would make human life as we know it unrecognizable. Americans would rightly consider a 10 percent chance of nuclear war unacceptably large. Even if all the Paris talks do is simply eliminate the risk of the all-too-thinkable worst-case scenario, it would constitute a monumental achievement in the history of human civilization, like the development of modern medicine.

The danger of black-and-white moralism is that it can be paralyzing. Ironically, the despair of the left has one quality in common with the denial of the right: They are both coping mechanisms. Denial is conservatism’s way of avoiding the collision between its belief that governmental power over the economy must not be extended and the likely truth that climate change is a problem that can only be solved through more government. Despair is a means of coping with the contradiction between the awesome scale of the climate crisis and the paucity of political tools to solve it. Both render us passive bystanders to history and, by hiding our agency, distort our vision of the world. An inability to parse degrees of too little and too late can blind you to something revolutionary and historic taking place.

Perhaps this is the best way to judge the world’s efforts in Paris: How does the outcome stack up against where the world stood a few years ago? After the 2010 collapse of Obama’s attempt to pass a cap-and-trade bill, the world appeared well and truly doomed. China was burning everything, the rest of the developed world was ready to follow along, and the U.S. had no obvious path to get its emissions under control.

Since that point, the long-awaited green revolution has finally arrived. Both energy technology and cooperative international willpower, mired for years in stasis, have been set into furious motion. The negotiators have constructed a different dynamic this time. Rather than set overall limits and require reductions of every country, they will get individual countries to set their own targets. The opening bids by the U.S., China, and Brazil have been an encouraging start.

The limits agreed to at Paris will not be enough to spare the world mass devastation. But they are the beginning of a framework upon which progressively stronger requirements can be built over time. The willpower and innovation that have begun to work in tandem can continue to churn. Eventually the world will wean itself almost completely off carbon-based energy. There is, suddenly, hope.

*This article appears in the September 7, 2015 issue of New York Magazine.