Attribution science, the branch of climate research that assigns observed changes to specific causes, has matured rapidly over the past decade. Earlier studies established methods for attributing a share of historical warming to individual companies, building on the Carbon Majors database, a comprehensive accounting of the emissions associated with the largest fossil fuel and cement producers in the world. Those efforts focused largely on the past and the present. Frierson and Henrie extended the approach forward in time, asking not only how much warming these entities have already caused, but how their historical emissions will continue to shape the climate system across coming centuries under different assumptions about humanity’s collective future.

To do this, the researchers turned to the Finite Amplitude Impulse Response model, or FaIR, a widely used reduced-complexity climate model that simulates the interactions between greenhouse gas emissions, atmospheric concentrations, radiative forcing, and global temperature. FaIR captures the essential physics of the carbon cycle and the atmospheric chemistry of methane and other greenhouse agents while remaining computationally efficient enough to run many simulations. The team ran the model out to the year 2500, an unusually long horizon for attribution work, and performed counterfactual experiments: simulations in which the emissions associated with the Carbon Majors were removed from the historical record, with the difference between the factual and counterfactual worlds representing the perturbation attributable to those entities.

The counterfactual technique is the analytical heart of the study. By comparing a simulated world that includes the emissions of the top 178 producers with an otherwise identical world that excludes them, the researchers isolated the corporate contribution to atmospheric carbon dioxide, methane, ozone, stratospheric water vapor, and ultimately global mean temperature. They repeated this comparison across several different future emissions scenarios, ranging from futures in which global emissions fall rapidly to futures in which they continue to climb. This design allowed them to test a question that has received little attention: does the warming legacy of past emissions look different depending on what the rest of the world does next?

The answer, perhaps unexpectedly, is yes—and in two opposing directions. For atmospheric carbon dioxide, the anomaly attributable to a company’s historical emissions is smaller, and carries less uncertainty across the model ensemble, in a low-emissions future than in a high-emissions one. The reason lies in carbon cycle feedbacks. In a high-emissions world, warming itself weakens the ability of oceans and land ecosystems to absorb carbon, so an initial pulse of carbon dioxide produces a larger and more variable atmospheric anomaly. In a cooler, lower-emissions world, those feedbacks are muted, and the extra carbon dioxide from historical emissions is drawn down more efficiently and more predictably.

Yet when the researchers translated those carbon dioxide anomalies into temperature, the picture reversed. The temperature change attributable to past emissions turned out to be larger in a lower-emissions future, even though the atmospheric carbon dioxide anomaly was smaller. The explanation is the logarithmic relationship between carbon dioxide concentration and radiative forcing: each additional part per million of carbon dioxide traps less additional heat than the part per million before it. In a high-emissions future, the background concentration is already so elevated that the corporate contribution sits on the flat, less sensitive portion of the forcing curve. In a low-emissions future, where concentrations are brought down substantially, the same corporate contribution occupies a steeper portion of the curve and therefore exerts a proportionally larger influence on temperature. In other words, the more successfully the world decarbonizes, the more visible the fingerprint of historical emitters becomes in the remaining warming.

Methane added a further twist. The simulations showed that after roughly 2080, the methane concentration anomaly attributable to the Carbon Majors turns negative, meaning the counterfactual world without their emissions actually contains more methane than the factual one. This counterintuitive result stems from atmospheric chemistry: methane’s lifetime in the atmosphere depends on temperature, and a warmer climate shortens the chemical lifetime of methane by accelerating its removal. The historical warming caused by corporate emissions therefore acts as a small negative feedback on methane concentrations in later centuries, partially offsetting—but nowhere near fully compensating for—the positive forcing from carbon dioxide.

Across every scenario the researchers examined, the net effect of the Carbon Majors’ historical emissions remained a warming one. The perturbations propagate through many linked components of the climate system: carbon dioxide in the atmosphere and in other reservoirs of the carbon cycle, methane, ozone, and stratospheric water vapor, the latter two arising as chemical byproducts of methane oxidation. When all of these contributions to radiative forcing are summed, the total stays positive throughout the simulations running to 2500, and positive forcing translates directly into positive temperature perturbations. There is no scenario in the study in which the corporate legacy simply cancels itself out.

The implications extend well beyond academic attribution. Courts, legislatures, and communities increasingly ask not just who caused climate change, but who bears responsibility for damages that have not yet occurred. This study demonstrates that such future damages are, in principle, calculable on timescales of centuries. Because the temperature perturbation attributable to each entity can be tracked through a physically consistent model under any given emissions pathway, the framework could in theory be coupled with damage functions and sea level projections to quantify ongoing liabilities. The researchers emphasize that the attributable warming is not a fixed historical quantity but a pathway-dependent one, which means that choices made in the coming decades will shape how the responsibility of past emitters is expressed in the climate of the future.

The study also carries a sobering message for the general public: the climate consequences of emissions already released are effectively locked in for many generations, regardless of how quickly the world now decarbonizes. Even in optimistic scenarios, the simulations show the Carbon Majors’ historical emissions continuing to raise global temperatures for centuries, interacting with carbon cycle feedbacks, atmospheric chemistry, and the logarithmic physics of radiative forcing in ways that keep their influence positive and quantifiable. As Frierson and Henrie conclude, in addition to the damages that have already occurred, these entities can be expected to be responsible for calculable climate damages for many centuries to come—a legacy written into the physics of the atmosphere itself.

Subject of Research: Attribution of centuries-long global warming to major fossil fuel and cement producers under future emissions scenarios

Article Title: Centuries of global heating from Carbon Majors: Dependence on future emissions pathways

Article References: Centuries of global heating from Carbon Majors: Dependence on future emissions pathways. (n.d.). https://doi.org/10.1371/journal.pclm.0001036

Image Credits: AI Generated

DOI: 10.1371/journal.pclm.0001036

Keywords: climate attribution, Carbon Majors, FaIR model, fossil fuel emissions, carbon cycle feedbacks, radiative forcing, methane lifetime, counterfactual simulations, PLOS Climate, global warming, emissions scenarios, climate damages

The Carbon Majors dataset is the most comprehensive public accounting of industrial carbon dioxide production at the entity level. Rather than attributing emissions to nations or to diffuse economic sectors, it identifies the specific companies and state-owned enterprises whose extraction, refining, and cement manufacturing activities released the greatest volumes of carbon into the atmosphere. Covering more than a century and a half of industrial history, the dataset aggregates the fossil fuel and industry emissions alongside agriculture, forestry, and other land use changes, providing a continuous record that climate scientists can feed directly into Earth system models. This entity-level resolution is what makes the new analysis distinctive: it allows the warming contribution of historically major producers to be isolated and tracked forward in time under different assumptions about the future.

The technical core of the study lies in its use of the Scenario Model Intercomparison Project framework, known as SSP, which defines a set of standardized future emissions trajectories used throughout the climate modeling community. The researchers ran simulations under four of these scenarios, spanning futures from low-emissions pathways consistent with ambitious mitigation to high-emissions worlds of continued fossil fuel expansion. Critically, they also constructed a counterfactual using the intermediate SSP2-4.5 scenario, in which the historical emissions of the Carbon Majors are removed from the forcing record. By comparing the counterfactual world against the real one, the team could quantify precisely how much warming the extracted and combusted carbon of these producers has caused and how much warming it will continue to cause under each future pathway.

The reason historical emissions lock in warming for centuries is rooted in the fundamental chemistry and physics of the carbon cycle. Carbon dioxide is a long-lived greenhouse gas: once emitted, a substantial fraction of it remains airborne for hundreds to thousands of years, because the natural sinks that remove it, primarily the oceans and terrestrial biosphere, operate on slow timescales. The ocean absorbs CO2 through air-sea gas exchange, but the surface waters that take it up mix only gradually into the deep ocean, a process that takes centuries to equilibrate. Meanwhile, the carbonate chemistry of seawater limits how much carbon the ocean can ultimately absorb, and weathering of silicate rocks, the only mechanism that removes carbon on geological timescales, operates over tens of thousands of years. The net effect is that a pulse of CO2 emitted today raises atmospheric concentrations and global temperatures for far longer than human planning horizons.

This persistence distinguishes carbon dioxide from shorter-lived climate forcers such as methane, which breaks down in the atmosphere within roughly a decade. For CO2, the warming response to an emissions pulse is approximately proportional to the cumulative amount emitted, and it does not decay away quickly even if emissions cease entirely. The study’s simulations capture this behavior directly: under every one of the four SSP scenarios examined, the temperature anomaly attributable to the Carbon Majors’ historical emissions remains elevated for many hundreds of years into the future. Even in scenarios where global emissions fall sharply or reach net zero, the committed warming from past production does not disappear. It is baked into the trajectory of the climate system, a thermal and radiative inheritance that future generations cannot opt out of.

The magnitude of this inheritance is substantial when viewed through the lens of corporate accountability. The Carbon Majors accounting has previously shown that a relatively small number of entities, roughly a hundred investor-owned and state-owned producers, are linked to the majority of industrial CO2 emissions since the mid-nineteenth century. The new work extends that accounting into the domain of climate consequence, translating tonnes of extracted carbon into degrees of warming and, crucially, into centuries of duration. The counterfactual simulations under SSP2-4.5 quantify the gap between the world as it is and the world that would exist had these producers’ emissions never occurred, a gap that widens through the twenty-first century and then plateaus rather than closing, because the emitted carbon simply persists.

The dependence on future emissions pathways, highlighted in the study’s title, cuts in an important direction. While the warming already committed by historical emissions cannot be undone on human timescales, the simulations show that the additional warming these emissions will cause in combination with future emissions depends on which pathway humanity follows. In high-emissions scenarios, the Carbon Majors’ legacy carbon compounds with ongoing emissions, pushing temperatures further along a trajectory of severe heating. In low-emissions scenarios, the legacy contribution becomes a larger fraction of the total warming, but the absolute temperature outcomes are far less dangerous. The practical implication is that past emissions set a floor, but future choices determine how much higher the ceiling rises. Mitigation decisions made in the coming decades govern whether the centuries-long legacy of these producers is experienced at 1.5 degrees of warming or at substantially higher levels.

The scientific and legal significance of this work extends beyond climate physics. Attribution science of this kind is increasingly relevant to litigation, regulatory policy, and climate finance, as courts and governments seek to assign responsibility for climate damages. By connecting named producers to quantified, persistent warming under standardized scenarios, the study provides a defensible, model-based bridge between historical industrial activity and future climate harm. The fact that the analysis is published open access in PLOS Climate, conducted without specific external funding, and accompanied by a declaration of no competing interests strengthens its utility as an evidentiary resource. The authors, based in the United States, released the underlying emissions visualization under a Creative Commons license, enabling independent verification of the dataset and the scenario comparisons.

For the broader public, the study’s most striking message is one of timescale. Human institutions, corporate strategies, and political cycles operate on horizons of years to decades, while the consequences of carbon extracted in the nineteenth and twentieth centuries will still be measurably warming the planet in the twenty-sixth and twenty-seventh. The coal burned to power Victorian factories, the oil refined through the twentieth century, and the cement poured into the infrastructure of industrialization are all, in a very literal sense, still in the atmosphere, still trapping radiation, and still committed to warming the Earth long after the companies that profited from them have transformed or vanished. Climate models make this inheritance visible and quantifiable, converting an abstract moral argument about intergenerational responsibility into concrete simulated temperatures across a millennium.

The research also underscores why cumulative emissions, rather than annual emissions alone, are the correct metric for climate policy. Because each tonne of CO2 contributes to warming in proportion to the total accumulated stock of carbon in the atmosphere, the historical production records of the Carbon Majors are not merely archival data; they are active components of the present and future climate forcing. The PLOS Climate simulations demonstrate that under every tested future scenario, from aggressive decarbonization to continued fossil expansion, the carbon already extracted by these producers continues to shape global temperatures for centuries. The study thus closes the loop between historical accountability and future climate outcomes, showing that the decisions of a relatively small set of industrial entities, made over 170 years, have committed the planet to a warming signal whose full duration no living person will see end.

Subject of Research: Centuries-long global warming contribution of historical emissions from major fossil fuel and cement producers under multiple future emissions scenarios

Article Title: The historical carbon emissions of major oil, gas, coal, and cement producers will contribute to global warming for many centuries, per simulations under a range of future emissions scenarios

Article References: The historical carbon emissions of major oil, gas, coal, and cement producers will contribute to global warming for many centuries, per simulations under a range of future emissions scenarios. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: Carbon Majors, PLOS Climate, climate modeling, SSP scenarios, carbon dioxide, fossil fuel emissions, historical emissions, global warming, carbon cycle, climate attribution, cement industry, centennial warming

The research focuses on the so-called carbon majors, a term used by researchers and activists to describe the 178 leading oil, gas, coal and cement companies whose products and operations have released the overwhelming majority of industrial-era greenhouse gases. Together, these entities have emitted more than a trillion tons of carbon dioxide, a staggering quantity whose atmospheric consequences do not simply vanish when the smoke clears. Carbon dioxide is a long-lived gas, and a substantial fraction of every ton released will remain aloft, trapping heat, for millennia. The study’s central insight is that this persistence creates a long tail of responsibility: the warming attributable to carbon majors is largely locked in, calculable, and relatively independent of what humanity chooses to do next.

To quantify that legacy, the research team turned to the Finite Amplitude Impulse Response model, commonly known as FaIR, a reduced-complexity climate model widely used to simulate how emissions translate into atmospheric concentrations, radiative forcing and global temperature change. The researchers ran simulations of the global climate all the way through the year 2500, exploring both low and higher emissions scenarios. Crucially, they ran each scenario twice: once with the historical emissions of the carbon majors included through 2024, and once with those emissions removed. The difference between the paired runs isolates the temperature signal that can be attributed specifically to the top producers, allowing the team to track how that signal evolves across a wide range of possible futures.

The results reveal a striking asymmetry. In a future where greenhouse gas emissions are sharply limited, the carbon majors account for a larger percentage of the total warming above preindustrial levels, because their historical emissions dominate a smaller overall budget. In higher emissions scenarios, where fossil fuel burning continues unabated and the planet becomes dramatically warmer, future emissions cause a much larger share of the total temperature change. Yet the absolute temperature contribution from the carbon majors remains roughly the same across scenarios. Dargan Frierson, a University of Washington associate professor of atmospheric and climate science and the study’s lead author, summarized the implication: the amount of warming attributable to the top emitters is calculable and relatively independent of future emissions, meaning their responsibility persists no matter which path the world takes.

The persistence of that warming has profound physical consequences. Even if humanity were to stop emitting greenhouse gases tomorrow, the environment would not revert to its preindustrial state. According to the study’s findings, Earth would remain approximately 1.5 degrees Celsius above preindustrial temperatures, the threshold that international climate policy has identified as a critical guardrail. Frierson put the conclusion bluntly: we expect continued warming of the climate until fossil fuel emissions stop, and the only stable future is one with no fossil fuels burned at all. In other words, there is no gentle landing. Every additional year of production by the world’s largest emitters extends and deepens the warming that future generations will inherit.

Why does past emissions translate into future disasters? The answer lies in the mechanics of attribution science, the field that connects individual extreme weather events to climate change. Over the past decade, attribution researchers have developed increasingly rigorous statistical methods to determine how much more likely, or how much more intense, a given heat wave, drought or downpour has become because of human-caused warming. These findings now form the backbone of a growing list of lawsuits attempting to hold major emitters responsible for deaths and damages incurred during climate disasters. The new study extends that logic forward in time: if persistent warming raises the baseline probability of extreme events, then gases released decades ago by leading producers may also be responsible for disasters that have not yet occurred.

This forward-looking dimension is what makes the research legally and ethically explosive. Efforts to hold emitters accountable have traditionally hinged on allegations that companies knew about climate risks many decades ago and concealed that information from the public, sometimes employing deceptive tactics to spread disinformation, as documented in archives such as the climate deception dossiers compiled by the Union of Concerned Scientists. The new analysis adds a second, quantifiable strand to that case: the gases released by extracting and burning fossil fuels are not merely a historical wrong but an ongoing mechanism of harm, one that will keep elevating the odds of future catastrophes long after the emissions themselves took place. Responsibility, as Frierson noted, is not just now; it will continue for many, many years into the future.

The timing of the study could hardly be more consequential. Courts around the world are weighing claims brought by cities, states and indigenous communities against fossil fuel producers, and the scientific credibility of attribution evidence has become a decisive factor in several of those proceedings. By showing that the warming contribution of the carbon majors is stable across emissions pathways, the research gives plaintiffs a robust number that does not depend on contested assumptions about future policy. It also gives regulators and policymakers a clear warning: future fossil fuel production will exacerbate climate disasters for many decades to come, which means new legal battles over accountability should be expected for years. Frierson emphasized that this is important for current decisions about fossil fuels, since every new extraction project adds to a warming burden that cannot be easily undone.

Underlying the entire analysis is a sober piece of climate physics. Carbon dioxide’s atmospheric lifetime is not measured in years but in centuries to millennia, and the ocean’s enormous heat capacity means that even after concentrations stabilize, the climate system continues to adjust. Reduced-complexity models like FaIR capture these dynamics by linking emissions pulses to temperature responses with well-constrained parameters drawn from the broader body of climate science. When the model runs with and without carbon major emissions diverge by a consistent margin across 500 simulated years, that margin represents real, physical, irreducible warming, heat that has already been committed to the system by past production decisions. No plausible emissions pathway can claw it back.

The study, co-authored by Lauren Henrie, a former student of Environmental Science and Resource Management at the University of Washington, ultimately reframes the climate crisis as a problem of accumulated, durable responsibility. The faucet is still running, in effect, and the water already in the house will keep spreading through the floors for generations. For the top 178 producers of oil, gas, coal and cement, the message is that their past is the planet’s future: the trillion tons of carbon dioxide already released will continue trapping heat, intensifying storms, and raising the odds of disaster long after today’s headlines fade. And for everyone else, the message is equally clear: the only stable future, the only one in which the warming finally stops climbing, is one in which fossil fuels are no longer burned at all.

Subject of Research: Attribution of long-term global warming and future extreme weather risk to historical emissions from the largest fossil fuel and cement producers

Article Title: Past emissions from top polluters will continue warming the planet for decades to come

Article References: Past emissions from top polluters will continue warming the planet for decades to come. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: carbon majors, climate attribution, fossil fuel emissions, PLOS Climate, University of Washington, FaIR model, extreme weather, climate litigation, carbon dioxide lifetime, global warming, emissions scenarios, climate accountability