Donald Trump took a climate report theme song, lifted it like a trophy and threw it into Truth Social with the delicacy of a triceratops. The acronym is RCP8.5, one of the most extreme climate scenarios used for years in studies on global warming. In his story, the revision of that scenario becomes a kind of universal confession.
The post cited the worst-case scenario farewell as evidence that it was “all fake.” In detail, he declares that “finally”, after 15 years in which the “Dumocrats” as he calls them, a play on words that we can translate as “stupidocrats”, promised that “climate change” would destroy the planet, the United Nations climate science panel has just admitted that its projections (RCP8.5) were “WRONG! WRONG! WRONG!”. It can be said that repetition does not leave much room for doubt. After all this enthusiasm, the US president’s post continues:
For too long climate activism has been used by “Democrats” to scare Americans, impose horrible energy policies, and fund their phony research programs with BILLIONS. Unlike the Democrats, who use climate alarmism nonsense to promote their NEW GREEN SCAM, my Administration will always be based on TRUTH, SCIENCE and FACTS!
It’s a shame that the review says something different: the most extreme path imagined fifteen years ago appears much less plausible today because the world, despite all its exasperating slowness, has changed some parts of the energy machine. Solar, wind, batteries, electric cars, climate policies, partial exit from coal: all stuff that hasn’t saved the planet with a magic wand, but has shifted the trajectory compared to the darkest scenario.
The acronym became a slogan
RCP8.5 was the nightmare future put on the table to understand what could happen in the event of a heavy and almost undisturbed rush to fossil fuels. A world even more dependent on coal, oil and gas. A world with very high emissions. A world capable of reaching around 4.5°C of global warming compared to the pre-industrial era by the end of the century. An enormous figure, of those that change coasts, crops, cities, health, water, insurance, bills, the entire condominium of human existence, even the one with the administrator who never responds.
That scenario, even when it was born, represented the high margin of risk. It also served this purpose: looking at the worst case, preparing, measuring what happens when the curve takes the worst path. Climate scenarios work like this. They are not fortune tellers in lab coats, they are tools. They are built with hypotheses on population, economy, energy, land use, technologies, public policies. If those variables change, the range of possible futures also changes.
The new architecture of the scenarios for CMIP7, the large cycle of climate models that will also feed the next IPCC report, has reorganized precisely this range. The work published on Geoscientific Model Development describes new scenarios for high, medium and low levels of climate change, linked to very different emissions and possible peaks and troughs in greenhouse gas concentrations over the course of the century. In practice, science updates the navigator because some paths have become less probable, others remain open, others still depend on what governments, industries and societies actually do. Trump, however, takes the updated navigator and uses it as if it were proof that the road does not exist. A classic: you change maps and someone shouts that the mountain was invented.
The good news that absolves no one
If RCP8.5 weighs less today, a share of the credit goes precisely to climate policies and clean technologies which for years have been treated as whims of environmentalists with water bottle in hand. The costs of renewables have fallen, electrification has advanced, some countries have reduced their dependence on coal, global emissions have stopped following the most extreme trajectory. Jonathan Overpeck, a climate scientist at the University of Michigan, explained that this shift reflects real progress in slowing climate change thanks to solar, wind, batteries and electrified transportation.
This is the good news. The bad news is that having come down from the worst future is not the same as having entered a safe future. Detlef Van Vuuren, lead author of the new scenario study, said it quite clearly: climate risks have not disappeared, we have avoided the most dramatic emission path, but we are still heading towards a future with significant impacts. It’s like going to the doctor, finding out that the scariest test is less likely than expected, and using that news to start smoking on the hospital sidewalk again.
Even the numbers from UNEP, the United Nations Environment Programme, remove any temptation to toast prematurely. According to the Emissions Gap Report 2025, if national climate commitments were fully applied, global warming over the course of the century would still be around 2.3-2.5 °C. Under current policies, the trajectory remains around 2.8°C. The report adds that countries are still far from the goals of the Paris Agreement and that every fraction of a degree avoided means fewer losses for people and ecosystems.
The climate doesn’t read posts
The revision of RCP8.5 also talks about a communication problem that we have been having for years. The climate scenarios have ended up in the meat grinder of public debate as if they were weather forecasts from apps: sun, rain, maximum temperature, end. The climate works over long times, probabilities, margins, uncertainties, trajectories. Social politics works on three seconds, capital letters, enemies, easy applause. The result is this short circuit: a scientific correction becomes a political absolution.
The question seems distant only as long as it remains closed in the acronym. RCP8.5, CMIP7, IPCC, SSP: an alphabet soup for professionals. Then July arrives, the city retains heat like an oven left on, the air conditioner becomes a question of social class, the crops suffer, the storms discharge water with the fury of a crazy washing machine, the coasts are eaten away one meter at a time and the acronym becomes matter again. There is no need to imagine the end of the world. Just look at the calendar of recent summers.
The next major IPCC report, the seventh assessment cycle, is already in preparation: the process formally began in 2023 and the summary report is expected by the end of 2029. New simulations, new scenarios, new data on impacts, adaptation and mitigation will enter into that work. Science will do what it has to do: update, discuss, correct, narrow uncertainty where it can and declare it where it remains.
Politics, meanwhile, will continue to choose what to do with it. He can use a technical review to say it was all made up. You can read the review itself as very simple proof: when you cut emissions, when you finance clean technologies, when you really change the energy system, the trajectories shift. Even slowly. Even bad. Even among a thousand contradictions. But they move.
What Trump pretends not to understand is that saying goodbye to the RCP8.5 scenario is not the funeral of climate science. It is confirmation that choices matter. You can also celebrate the theme song that comes out of the scene. Just don’t mistake it for the thermometer. That stays on.
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