The 1.5°C temperature target is difficult to honestly and openly discuss. Within the climate movement, it has become a locus of anguish, confusion, and even despair. Long a symbol of mobilization and hope, 1.5° has become central to both activist campaigns and scientific analysis. Yet it’s now clear that the planet will almost certainly warm more than 1.5°C.
This is a rough prospect. It will likely condemn countless communities, many of them largely innocent of responsibility for the climate crisis, to suffering and destruction on a vast scale. It will trigger major ecological crises, extinctions first among them—the coral reefs, to pick just one example, could almost entirely vanish as the warming breaches the 1.5°C line.
These are not encouraging words, but they should not be taken as invitations to despair, or to a strange denialism in which, fearing hopelessness, we soft-pedal the severity of our circumstances. Because the truth is that the planet is not doomed, and neither are the world’s most climate vulnerable people.
The message here is that it’s time to act. Fortunately, significant action seems finally to be possible. At the last climate summit, after a grand push from the Global South coalition (the G77 + China) and the climate movement, the long-deadlocked battle to establish a “loss and damage” fund was finally won. That fund could finance disaster prevention and disaster mitigation in regions that have been pushed beyond their adaptive capacities. There will, of course, be limits to such interventions, but this could be the beginning of real climate internationalism. And it would not be alone. To cite just one other justification for cautious optimism, the renewable technology revolution has finally arrived.
Still, implacably, year by year, the “emissions budgets” are being drawn down, and the IPCC’s new “Synthesis Report” has made this undeniable. We’re going to hit 1.5°C. Thus, if 1.5°C is still achievable, it is only by way of an “overshoot and decline” pathway in which the temperature, in time, drops back below 1.5°C. As Peter Thorne, a physical geographer at Maynooth University in Ireland, noted at the report’s launch, “Almost irrespective of our emissions choices in the near term, we will probably reach 1.5 degrees early in the next decade.… The real question is whether we reach 1.5 degrees and then maybe go a little bit over and come back down or whether we go blasting through one and a half degrees and two degrees and keep on going.”
The challenge now is to limit the depth and duration of the 1.5°C overshoot and thus the destruction that occurs during and after it. This means, among much else, rapidly phasing out fossil fuels, a tremendously challenging prospect that will disrupt economies and political alliances around the world. Such a phaseout can succeed only if it unfolds in a manner that is widely accepted as fair.
The 1.5°C target has been tactically indispensable, and it remains so. But we have a problem: The idea of an ambitious transition from fossil fuels has been anchored to the 1.5°C number—as in the slogan “1.5 to stay alive”—and punching through that line can feel like we’ve lost the battle for an ambitious response. But this feeling is misleading. Given the unwillingness of the elites to act responsibly, the 1.5°C breach was inevitable, but it was always mobilization, not 1.5°C itself, that was the point. This is still true, and every tenth of a degree matters. With or without the 1.5°C target, we face a bitter, complex, and protracted battle to sideline the fossil fuel cartel and pioneer a global decarbonization strategy. And without international cooperation, our odds are terrible.
It’s helpful to review the language of the Paris Agreement, which commits the world’s nations to “holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels.” But don’t make the mistake of thinking that, because “limiting the temperature increase to 1.5°C above pre-industrial levels” is difficult, “holding the global average to well below 2°C” is going to be easy. Far from it, especially since “holding” implies that there will be no temporary overshoot.
Kristy Dahl, a climate scientist at the Union of Concerned Scientists, summarized a review of the major studies as follows: “The models are showing that global emissions have to peak before 2025 and decline by about 43 percent relative to 2019 levels by 2030 if we want a 40 percent chance of holding the warming to 1.5°C without overshoot.” Note two things here: The first is that, absent an immediate reordering of international society, a 43 percent by 2030 drop is simply not going to happen; the second is that even if it did, a 40 percent probability of success is ridiculously low.
Meanwhile, “well below 2°C” is probably best understood as 1.7°C. I don’t want to get too far into the numbers here, but if you check the recent IPCC reports—for instance, the “Working Group 1 Summary for Policymakers”—you’ll see that the remaining 1.7°C carbon-dioxide emissions budget (from the start of 2020, a 50 percent probability of success) is only 350 gigatonnes greater than the 1.5°C budget. At current burn rates, this is less than an additional decade, which is not much. The difference here—and it’s a huge one—is that, with an additional 350 gigatonnes, success is still possible. We can still hold the warming “well below 2°C,” but only if, as UN Secretary General António Guterres put it during the “Synthesis Report” launch, we do “everything, everywhere, all at once.”
All these numbers are political, but they are not merely political numbers. The 1.5°C temperature target, in particular, is not given by nature. It represents a scientifically informed political judgment that balances dangers and damage estimates against achievability. The 1.5°C target was the lowest plausible target, as it was understood in a moment now past. It was widely seen as a survival target, though in truth not everything and everybody will survive at this level—a 1.0°C target would have been far preferable, and almost three decades ago, there was an effort, spearheaded by Greenpeace International, to put one on the table. This effort failed, and years passed before pressure from the Alliance of Small Island States and the Least Developed Countries became overwhelming enough to finally force a high ambition temperature target—the 1.5°C target—onto the formal negotiating agenda.
This 1.5°C target has proven its utility. A great deal of science has been calibrated to it, and we now know that beyond 1.5°C the dangers rapidly increase. To give just one example: At 1.5°C of warming, 14 percent of the human population will be exposed to severe heat at least once every five years, while at 2°C this figure jumps to 37 percent. It is easy to understand why 1.5°C has become the standard against which all pledges of action, both national and corporate, are measured, and against which almost all fall short. Which is exactly why it cannot be given up.
But how to keep 1.5°C alive when the line will soon be breached? Only by embracing the truths of the impending overshoot, which include its temporary inevitability. This is difficult for climate activists, who know well what surpassing 1.5°C will mean in terms of blood, suffering, and irreversible loss.
The dangers of overshoot are intolerable, and it would clearly be better if we could take “limit to 1.5°C” to mean “keeping below 1.5°C” rather than overshooting and then returning to it on the way to lower, safer levels of warming. But the science behind the “Sixth Assessment Report” suggests it is no longer possible to keep warming below 1.5°C. Still, 1.5°C remains an essential guide as we navigate a future of overshoot and hopefully decline, and it must become the metric by which to measure the overshoot and a target to which we must return. This is realism, not surrender.
In all this, the imperative is transformative global action. As we enter a future in which 1.5°C of warming has become, or is about to become, a fact, it will become easier for the fossil powers to cast further warming as unavoidable, and thus to counsel delay and complacency. Already, “business figures,” as the Financial Times describes them, “are starting to argue in private that it would be better to put more emphasis on planning for a world with warmer temperatures than to focus on what is now likely to be an unachievable goal.”
The hypocrisy is reaching surreal levels. Sultan al-Jaber—the chief executive of Abu Dhabi’s state oil company and the president of the next UN climate summit in Dubai—argues that the Paris temperature goals are still in sight. But really the point is to soften us up for carbon capture and storage add-ons to the fossil economy. And he continues to flack for a long stream of fossil fuel projects that, if built and operated to the end of their projected lifetimes, would make achieving even the weakest possible interpretation of the Paris temperature goal impossible.
The challenge now is to use the truth to our advantage. Basav Sen, the climate-justice project director at the Institute for Policy Studies, argues that the grim realities of a world in manifest overshoot are nothing if not arguments for “doubling down, and even tripling down on everything we’ve been saying about the necessity of justice and ambition.”
The future is not entirely obscure. The average global surface temperature is going to keep rising, and someday soon—maybe in seven years, maybe in five, maybe even the next time La Niña returns—it’s going to hit 1.5°C. This will be a temporary breach, and the temperature will then drop back down. But the graphs will keep rising, and soon they will trace a line that is decisively above 1.5°C. By that time, the battle over “negative emissions” will be everywhere, and it will be imperative to win it, which means defining drawdown primarily in terms of reforestation, revegetation, and restoration, rather than relying on unproven, expensive, and unscalable carbon dioxide removal technologies.
By that time, too, we had better have a reasonably detailed shared vision of a just transition that works not only in the wealthy precincts of the planet but around the world. This vision will need to entail a grand global finance bargain capable of driving a rapid phaseout of fossil energy. Such a phaseout will not be cheap, because it will have to be seen as fair, and this means something different from, say, a process of creative destruction in which each country, however poor or vulnerable it may be, is left to manage on its own. At the minimum, all people everywhere have a right to dignified lives, which must include access to electricity as it must include access to safe water and housing, transportation, and health care. This means development paths for all, and it means a managed transition in which wealthy people and wealthy counties bear their fair shares of the transition costs. Trillions of dollars will have to be moved from the rich world to the poor.
The only way winning back 1.5°C can become possible is if the fossil fuel cartel is decisively beaten. The banks must stop funding fossil energy. There will have to be energy leapfrogging in Africa, and around the world, and a global finance and technology sharing system to support it. Huge amounts of international debt will have to be written off, so that Global South countries can prioritize their development needs. The Chinese central government will have to move against its energy security concerns and its provincial governors and rapidly phase out coal. The Indian elites will have to join them, even if it means undermining local fossil interests. The multilateral finance institutions will have to be reimagined and redirected.
All of this is necessary, and possible, but only if the global right, which has become so entwined with the fossil fuel cartel as to be effectively part of it, is finally and permanently discredited and abandoned. And only if the climate movement steps forward with a program designed to catalyze a major social pivot that embraces, but goes far beyond, the renewable energy buildout. This is what we need now, as we hurtle toward the 1.5°C line.