For fifteen years, a large portion of the climate conversation has lived under the shadow of an extreme scenario: RCP8.5 and, later, its successor SSP5-8.5. Neither described the most probable future, but both ended up working as the backdrop against which studies, headlines, and impact projections were framed. Now, a new scientific framework for climate scenarios places them outside the range of plausible futures. The news is technical—and therefore has attracted little media attention—but it will change the underlying tone of a global debate that Spain should not keep postponing.
What was announced, exactly
On April 7, Geoscientific Model Development published a paper signed by 42 scientists led by Detlef van Vuuren of the Dutch environmental agency PBL. The text presents the new CMIP7 scenario framework—the generation of models that will feed the next IPCC assessment cycle—and concludes that the emission levels in SSP5-8.5 “have become implausible” due to falling renewable costs, the emergence of climate policies, and recent emission trends.
It is worth introducing four nuances. The first, from an institutional standpoint: it has not been the IPCC, as such, that formally removed RCP8.5, but the scientific project that prepares the scenarios for the upcoming climate-modeling cycle. The second, more technical: although RCP8.5 and SSP5-8.5 are not identical—belonging to different generations of scenario families—they have fulfilled the same function: to represent the high end of emissions and warming. Their joint withdrawal is what lends weight to the announcement. The third is an epistemological caution: the loss of verisimilitude should be read not as a mathematical property but as an informed judgment about technological, energy, demographic, and policy trends. The fourth is a methodological caution: the results are subject to scrutiny and the temperature projections are preliminary.
In any case, we are not looking here at the consequences of a sudden reversal. The fifth IPCC report, published in 2013, incorporated RCP8.5 as a reference trajectory, and many studies subsequently used it as a standard baseline. But over time, that reading became harder to sustain. The sixth report, in 2021, already warned that very high-emission scenarios should not be presented as trend projections. Consequently, the current movement represents the culmination of that gradual withdrawal.
What replaces the old catastrophe narrative
The new framework abandons the SSP nomenclature and proposes seven trajectories that run from VERY LOW to HIGH. The difference is that even the bleakest scenario in the new set stays below the old extreme. While SSP5-8.5 reached roughly 128 gigatonnes of CO₂ per year by 2100, the new HIGH scenario tops out at 71 gigatonnes: still a very high level, but far from the fossil-fueled hypertrophy that sustained the old trajectory. In terms of temperature, that new HIGH scenario yields about 0.9 °C lower than SSP5-8.5 in a like-for-like comparison. In other words, it still describes a severe future, but it no longer reproduces the horizon of collapse that the withdrawn trajectory once fed.
“The intermediate scenario is anchored to existing policies, but these policies extend forward without major improvements and decarbonization progresses by technological and economic inertia”
Not only that. The authors emphasize that not even the HIGH scenario should be read as a trend projection: it describes a world in which deep pessimistic deviations—political, technological, and structural—from current trajectories occur. The MEDIUM scenario, however, is perhaps the politically most relevant. It is anchored in current policies, but these policies extend forward without major improvements and decarbonization progresses by technological and economic inertia. Yet the outcome remains well away from the old apocalyptic extreme: roughly between 2.7 and 3 °C by the end of the century, according to the preliminary reading. Worrisome and demanding, yes, but not the collapse that the withdrawn scenario had projected.
The implications for public discourse are substantial. The dominant catastrophe narrative and the civilizational-collapse imagination that steered much of the public debate for years lose some of their empirical anchor. That imagination rested on assumptions that now appear dystopian: massive fossil-fuel consumption throughout the 21st century, a world population approaching 13 billion, and an almost total absence of climate policies. None of those three assumptions aligns with today’s observable trends. The energy transition is incomplete, uneven, and contentious, but it exists. Renewables have become dramatically cheaper. Climate policy has become institutionalized. Although emissions have not fallen enough and Paris Agreement targets will not be met, they do not follow the exponential trajectory of the most extreme scenario.
If the worst-case scenario ceases to be realistic, what changes in the climate policy debate?
Five shifts in the climate debate
The first shift is discursive. Climate policy must lean less on the language of degrowth and more on the logic of investment. For years, advocacy for climate action over-relied on the catastrophe of the worst imaginable future to justify sacrifices. That strategy carried costs, as it fed climate fatigue, gave ammunition to denialism, and allowed some sectors to use climate concerns as a vehicle for anti-capitalist agendas unrelated to emissions reductions. Without the threat of climate collapse as the central argument, calls for permanent material austerity and for curtailing growth as a price to save the planet lose credibility. Action must be directed toward what actually works to achieve realistic goals: technological innovation, cheaper clean energy, energy security, industrial competitiveness, infrastructure resilience, and protection against already inevitable physical risks.
The second shift is timing and horizon. The climate conversation has rested on the frame of the year 2100, and that may have been a misstep. If the worst-case scenario, whose dramatic force rests on distant horizons, no longer serves as the reference, climate policy can no longer hide behind grand, far-off objectives as a distraction; it must demonstrate the capability to deliver in today’s bottlenecks. The debate stops being about what a government promises in order to avert future catastrophe and becomes about how it demonstrates, with credibility, that it can mobilize, finance, and implement concrete policies now.
“Modernizing forest management, protecting coasts, adapting cities to heat and redesigning insurance is no less climate than installing solar panels”
The third shift is adaptive. This may be the point that has been hardest for parts of European environmentalism to accept. While the withdrawal of RCP8.5 does not erase the need to prepare, it makes the preparation more concrete and therefore unavoidable. Accepting the more realistic scenarios, adaptation must stop being framed as a defeatist concession and start being seen as a government obligation. Spain knows this better than many countries: droughts, wildfires, floods, heat waves, insurance, and critical infrastructure are not abstractions. Modernizing forest management, protecting coasts, adapting cities to heat and redesigning insurance is no less climate than installing solar panels. It is the other side of the same task.
The fourth shift affects the financial and regulatory ecosystem. In recent years, central banks, insurers, and financial institutions have used climate scenarios to explore physical and transition vulnerabilities. They did not employ RCP8.5 mechanically or treat it as a literal forecast. Yet the mental framework of the worst-case scenario has weighed on how climate risk is translated into expected losses, disclosure requirements, resilience tests, and supervisory narratives. The new framework does not invalidate those exercises, but it calls for recalibration. Extreme scenarios will still have value as stress tests, just as an extreme pandemic or a global conflict can test resilience. But there will be little sense in using them as an implicit reference for the future.
The fifth shift is civic. The loss of dramatic appeal obliges climate social action to evolve. Activism, private philanthropy, public campaigns, and corporate commitments have long fed on an apocalyptic narrative that now loses steam. It has managed to raise awareness, but it also generated anxiety and visceral rejection. Now that the most extreme scenario is off the table, climate mobilization will need new registers. That is, less perpetual alarm and more capacity to monitor and scrutinize what is already being done. And that reinvention is urgent. In the United States, a blend of political hostility, corporate retreat, and philanthropic fatigue is already evident. In Europe, indicators of the same fatigue are clear.
What changes and what doesn’t
It is also useful to clarify what this revision does not imply. Climate change remains a serious threat. Realistic trajectories continue to require a substantial reduction in emissions, a faster deployment of clean technologies, and significant investment in adaptation. It does not imply that climate policies were a mistake. In fact, the article itself attributes part of the loss of plausibility of the worst scenario to the deployment of climate policies and to the falling costs of renewables. In other words, action, technology, and markets have worked.
“Climate science demonstrates with this revision one of its greatest virtues: it corrects its scenarios when the data and analysis indicate it”
A good news is that climate science demonstrates with this revision one of its greatest virtues: it corrects its scenarios when the data and analysis indicate it. That should bolster its authority. The bad news is that public debate is not always ready to process corrections that reduce the plausibility of the worst case. In the past, climate communication rewarded the most dramatic curves, the gloomiest headlines, and the most absolute narratives. Now the aim is to land with sobriety and adjust the diagnosis toward the range of plausibility. It weakens alarmism, but also complacent denial of those who insist that acting does not change the climate.
From there comes an opportunity to reinvent climate policy, steering away from ideological reflexes and toward more pragmatic principles: technology, markets, adaptation, administrative reform, private investment, and innovation. Not climate policy as collective penance, but as modernization. Not a transition conceived against the economy, but through the economy. Not an agenda measured by the number of prohibitions, but by its ability to reduce emissions, lower energy costs, and strengthen infrastructure to protect citizens from real climate damages.
The withdrawal of the worst scenario does not absolve the world of acting. It compels it to act better. It demands less grandiosity and more execution. The climate policy to come should look less like a crusade and more like a public work: less epic, more engineering; less banner, more plans. That is how durability is built.
