Support urgent efforts to repair leading climate models

Right now is a pivotal time in the climate modeling community. In summer 2025, window opened for the first time in 7 years that allows researchers to recommend changes to leading climate models used by the UN and world leaders to set climate policy meeting agendas.

These models ultimately impact the shape of climate policy around the world, and we have just a matter of weeks to finalize recommendations for changes to these models before they are "locked in" until the early 2030s.

The trouble is, our team has identified something that urgently needs to be changed in leading climate models, and currently no one else is working on it. On top of that, we have lost all our funding. Specifically, we have identified a form of fossil-fuel-funded misinformation that has been congealed into leading climate models. This misinformation has played a role in delaying climate policy action.

Please brace yourself, because the type of misinformation we identified in the models is something of a golden calf to many environmental activists:

We have identified what we call “overpopulation metrics” in leading climate models. These metrics falsely equate human population numbers with emissions, even though there has never been any data to back this idea up.

These metrics are easily debunked, and their origins can be traced to fossil-fuel-funded interference in the sciences that occurred between 1950-1970. This interference in the sciences by fossil fuel interests has been documented in Dr. Emily Klancher Merchant’s book, Building the Population Bomb: How Fossil Fuel Interests Created the False Image of Scientific Consensus Around the Idea of Overpopulation (2021). (The book doesn’t actually have that subtitle, but it should!)

Starting in 2019, our research team led by Harlin/Hayley Steele began investigating leading climate models used by the UN and world leaders. We've found that, indeed, these models repeat the myth that human population size is somehow correlated with emissions without evidence.

It is easy to debunk the idea that human population numbers are somehow the cause of emissions. Currently, there are seven countries on the planet with 100% renewable energy. It is possible for a person to travel to one of these counties, drive an electric car, and limit their diet to fossil-free food and have their "personal" carbon footprint drop to zero. If it is possible to have a person's carbon footprint drop to zero by switching to a different location and making a few simple lifestyle choices, this means that human population numbers are not inexorably bound to emissions. Yet, leading climate models currently repeat the fossil-fuel-funded misinformation that human population size is somehow a driver of emissions.

There is no data, anywhere, to back up the claim that human population size is correlated with emissions. Our team took the time to read all of literature that is used by leading models to justify the inclusion of baseless "overpopulation metrics." What we found was that none of these models cited any evidence at all to back up the claim that human population numbers and emissions are somehow correlated. Rather, they cited "models" created by fossil-fuel-implicated institutions in the 1970s that fabricated the idea that human population size is tied to emissions by obfuscating the existence and scalability of renewable energy sources.

Electric cars have been around since the 1880s, and wind turbines that generate electricity were invented in 1887. Only by obfuscating these alternatives was it possible for those with fossil fuel interests to fabricate the claim that human population size and CO2 emissions are somehow connected. And due to forms of fossil-fuel-funded meddling in the sciences, this myth that human population size and emissions are somehow connected got congealed into early climate models—and this myth got grandfathered in to leading climate models that are still used by the UN and world leaders today.

There is an urgent need to remove this myth and repair these models. When world leaders encounter the myth of "overpopulation" in models, to creates the false impression that reducing the number of humans on the planet will decelerate emissions. This leads them to repeat eco-fascist talking points during policy meetings that cause coalitions to break down. This delays the passage of climate policy, as robust coalitions are absolutely necessary to pass policy of this nature.

If you want to learn more about any of these things, please check out our citations on this poster here: basedmip.ucdavis.edu/posters.

Wildly, our research team is currently the only group in the world with the potential to remove the overpopulation metrics from the leading climate models in time for the IPCC deadline, which is technically at the end of the year, but we also have to meet a series of review deadlines every couple of weeks until then. If we miss any of these deadlines, there won’t be another chance to remove these metrics form the models until the early 2030s.

If this is going to happen, we need your support!

We didn't realize that we'd end up being the only research team set up to tackle this issue. We're still trying to wrap our heads around how this happened. We hypothesize that this occurred in part due at UC Davis, where we gained easy conversational access to relevant metadata that pertains to this work. Essentially, thanks to water cooler conversations at the ModLab, where some of us were based, we learned about Dr. Merchant's research into fossil-fuel-funded meddling in the sciences while her research was unfolding. We were engaged in youth-led projects to incorporate climate data into games at that time, and her work helped explain "glitches" we were noticing in leading climate models, including the easily debunkable metrics that inaccurately tie human population size to emissions. Due to our own proximity bias, we assumed all climate data researchers were also familiarizing themselves Dr. Merchant's work. This, however, wasn't the case. We hypothesize that due in large part to the information slump during the pandemic, which is when Dr. Merchant released her book, her work became highly institutionally siloed. We incorrectly assumed that other climate data research teams were drawing upon her work to unite metrics with appropriate metadata and debunk metrics with no basis other than fossil-fuel-funded myths. However, as it turns out, that was just us. Presently, we're the only research team positioned within the IPCC assessment cycle process with the ability to suggest this change to the models. Other research teams are bound to their present grant cycle's hypotheses, and unfortunately, none of them included repairing/removing the "overpopulation metrics" as part of their research. Our team has been doing this research since 2019, and we're the only team prepared to format this work in such a way that it will be considered as part of the recommended changes to the IPCC models.

But due to a combination of federal "DOGE cuts" and the Wall-Street-Indicted UC budget shortfall, the funding we need to do work has vanished.

We need to raise $20,000 by December, and at least $5000 by September 20th to ensure this work is able to occur.

Who are we?

We are a team of researchers who are part of a project based at UC Davis called BasedMIP. BasedMIP's core mission is to increase youth input to leading climate assessment tools, while also drawing upon cross-disciplinary research to develop climate assessment tools that are easier for everyone to understand and use, tools that allow everyone to access and discuss the same climate data that our leaders look at during climate policy meetings. This ensures that youth researchers and constituents can meet policy makers where they are at, using the same data sets as reference points. Our ability to do this work rests upon making sure that leading climate models are free of fossil-fuel-funded misinformation. We don't want to train youth researchers to use climate models that we know are wrong, but we also want to make sure they are in sync with what political leaders are looking at so these youth researchers can meaningfully engage with public discourse. We've been involved with leading climate modeling communities since 2022, when members of our team first attended Scenarios Forum 2022. We shared a poster and two talks as part of that meeting that cited Dr. Merchant's work, and we falsely assumed that this would be enough to encourage others in this community to take up this research, and to do the work to remove the related fossil-fuel-funded misinformation from the models. Our director, Harlin/Hayley Steele, takes full responsibility for not being clear enough about these issues in 2022. Steele merely recommended that the scientists read the book in 2022 without fully explaining why. This appears to have not had the intended impact, and we have found that no other research teams took up the issue.

Sorry for the novel, but we're still in disbelief about this.

Our team had planned basically go into furlough during the autumn, and to find other work while we wait for the funding cut chaos to play out. We thought that sending the youth researchers to Scenarios Forum was the finish line—thanks to generous support from a crowdfunding campaign, we were able to send our whole youth research team (some in-person and some as online attendees) to Scenarios Forum, where they were able to present their research into novel indicators (such as the emissions impact of war, income inequality, and mass displace) that are currently left out of leading climate models.

That research emerged based upon the assumption that the UN-affiliated modelers were already working to remove the baseless "overpopulation metrics" from their models based upon the citations we thought they had read from our presentations in 2022. As it turned out, no one read our citations, and because we weren't explicit enough about this issue in our presentations, no one took it up. We will properly chide ourselves about this later, but in the meantime, we are in a pickle: We can't just furlough the project this autumn after all, not if we want to make sure the recommendation to remove the broken "overpopulation" metrics gets into the IPCC in time. We need your help to make this happen.

Our work, which we hope to continue, goes much further than these time-sensitive efforts to remove the fossil-fuel-funded, baseless "overpopulation" metrics from leading climate models.

Our work includes:

Our work is always time-sensitive, insofar as every ton of CO2 we can keep out of the atmosphere is a win for our collective future. However, our work turned wildly time-sensitive this summer, as the IPCC window to contribute to models opened up. First we thought the issue was just to get our youth researcher's metrics to be "in-process" for consideration to be included in the climate models. But once we got to the meeting, it became clear there's a much bigger task before us: we need to rapidly work to format our recommendations to remove the "overpopulation" metrics from models, and we need to submit and reformat them to meet a series of deadlines that will begin unfolding between late September and the end of the year.

What the funds go towards:

Our current research team includes:

To learn more about additional members of the BasedMIP research team and our affiliates, please visit: basedmip.ucdavis.edu/people

If this project is fully funded, it will support the onboarding of a new team of undergraduate researchers in September. This new team will join the director in the process of navigating the IPCC deadlines to ensure that the model repair is properly considered. This work will help train a new cohort of young adult climate data researchers, while completing the model repair necessary to ensure we able to continue our mission to facilitate the development of robust, youth-led climate assessment tools.

Thank you so, so much for any and all support of our work. Together, let's steer towards the best climate outcome that's still possible.