[ Repub ] "The IPCC consensus is manufactured"

Role of CO2 in climate change, of natural variability, consensus (or not), effects and counter-effects... We interviewed two climatologists. Second part with Judith Curry.

As French President Emmanuel Macron hosts another high-profile international summit, this time to address ocean conservation—a topic arguably more critical than greenhouse gas emissions—science is once again being used to silence dissent. Contrary to its stated focus on ocean conservation, the Blue Economy and Finance Forum in Monaco, where Emmanuel Macron is spoke on June 8-10, 2025, primarily promotes ocean exploitation. The event emphasizes economic opportunities over genuine environmental protection.

We are republishing our interview with Judith Curry, who warns against the misuse of science and advocates for critical, objective scientific discourse over narratives shaped by interest groups.

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Few media outlets in France, except Guy Sorman for Le Point, would interview or even quote Judith Curry, preferring instead to label her a Trumpist or climate conspiracy theorist.

Yet, scientists acknowledge her as an authoritative climatologist. Some criticize her methods, while others cannot forgive her for publicly diverging from their consensus on climate and its evolution, effectively leaving their "conclave."

In the United States, where Judith Curry has had a long and distinguished career, she is listened to, even if often criticized. In France, she is largely ignored. This reflects the state of the French press and its commitment to pluralism.

Judith Curry has expressed doubts about climate change, citing the uncertainty of natural variations, which she believes are marginalized by an IPCC whose sole mission, according to her, is to validate human responsibility. She also points to the significant imperfections in climate models. Just days after our exchange, a team of researchers announced efforts to improve these inaccurate models.

In this interview Judith Curry discusses climate change and its uncertainties, as well as what she calls the "manufacturing of consensus," which led her to leave academia. She was head of the Department of Earth Sciences at the Georgia Institute of Technology.

Since then, she has pursued her career in the private sector and has published a book, Climate Uncertainty and Risk: Rethinking Our Response, in which she invites readers to reconsider the prevailing climate change narrative.

L’Eclaireur - What does science state about climate change ? What major doubts are set forth ? 

Judith Curry - Climate change associated with increasing concentrations of atmospheric CO₂ is a theory in which the basic mechanism is well understood, but whose magnitude is highly uncertain.

There are three incontrovertible facts about global warming : the average global surface temperatures have overall increased since about 1860. CO₂  has infrared emission spectra, and thus acts to warm the planet. Humans have been adding CO₂ to the atmosphere via emissions from burning fossil fuels.

The above facts are strongly supported by scientific evidence, and there is no significant disagreement in the scientific community on these points. However, these three facts, either individually or collectively, do not tell us much about the most consequential issues associated with climate change.

Whether and to what extent CO₂  and other human-caused emissions have dominated over natural climate variability as the cause of the recent warming. How much the climate can be expected to change over the twenty-first century. Whether warming is dangerous. Whether radically reducing CO₂ emissions will improve human well-being in the twenty-first century.

The first two points are in the realm of science, requiring logical arguments, model simulations, and expert judgment to assess “whether” and “how much.” The issue of “dangerous” is an issue of societal values, about which science has little to say. Whether reducing CO₂ emissions will improve human well-being is an issue of economics and technology, as well as being contingent on the relative importance of natural climate variability versus human-caused global warming for the twenty-first century.

L’Eclaireur - To what extent does human activity contribute to raising temperatures ? 

Judith Curry - Human activities influence climate through changing land use and land cover (e.g. urbanization, deforestation, agriculture). Humans are also changing atmospheric composition by increasing the emissions of CO₂ and other greenhouse gases and by altering the concentrations of aerosol particles in the atmosphere.

The sensitivity of global temperatures to increasing concentrations of CO₂ in the atmosphere is highly uncertain; even the IPCC acknowledges a factor of 3 uncertainty in this sensitivity. Until we have a better understanding of natural climate variability and the sensitivity of the climate to increasing atmospheric CO₂, the extent to which the recent warming can be explained by CO₂ emissions remains uncertaint.

L’Eclaireur - How come other factors (solar activity, volcanic eruptions, earth axis rotation, hurricanes etc.) find little echo  ? And what is their importance compared to greenhouse gas emissions ?

Judith Curry - The remit for the IPCC is to identify evidence of human caused climate change, which has marginalized any consideration of natural climate variability.  A series of explosive volcanic eruptions such as occurred in the first half of the 19^th century would fundamentally change the course of 21^st century climate.  Solar activity, including solar indirect effects on climate, deserves much more attention from the climate community.

L’Eclaireur - Is there a true scientific consensus as the IPCC (and the majority of the medias) keeps on stating ?

Judith Curry - There is a key difference between a “scientific consensus” and a “consensus of scientists.”  A scientific consensus is a relatively stable paradigm that structures and organizes scientific knowledge. For genuinely well-established scientific theories, the concept of consensus is irrelevant. For example, there is no point in discussing a consensus that the Earth orbits the sun, or that the hydrogen molecule has less mass than the nitrogen molecule. By contrast, a “consensus of scientists” represents a deliberate expression of collective judgment by a scientific institution or a group of scientists, often at the official request of a government or other organization.

Under the auspices of the IPCC, the international climate community has worked for the past 30 years to establish a scientific consensus on human-caused climate change. The IPCC has codified consensus seeking into its assessment procedures: “In taking decisions, drawing conclusions, and adopting reports, the IPCC Plenary and Working Groups shall use all best endeavours to reach consensus.” The IPCC consensus has been described as a “manufactured consensus” (or a consensus of scientists), arising from an intentional consensus building process.

So what we have is a carefully selected group of scientists negotiating and manufacturing a consensus on dangerous human caused climate change at the behest of UN policy makers.

L’Eclaireur - Shall sole climatologists be legitimate to discussing climate change ? Why are so many "non-climatologist scientists", starting with physicists, questioning the “narrative” of climate change ?

Judith Curry - Climate science has become an exceedingly broad field, including ecologists, economists, policy sciences, and many other fields.  These peripheral fields are far from the core disciplines of atmospheric science, oceanography and geology that provide the basis for understanding of climate dynamics which is the core study of the fundamental physical processes and their complex interactions that cause climate change and variations.  So an ecologist who studies climate impacts can call themselves a climate scientist, but they can do little more than recite IPCC talking points when it comes to what is causing climate variability and change; they don’t have the technical background to critically evaluate this.

A physicist, on the other hand, has the background knowledge to critically evaluate the IPCC’s models and arguments about what is actually causing climate change and variations. Most importantly, physicists work outside of the academic climate change ecosystem and there is no reason for them to play that particular game, and hence they can be more objective than a climate scientist relying on government grants.

L’Eclaireur - With regards to climate, is there still room (has there ever been one) for controversy , the basis of science ?

Judith Curry - In the universities, unfortunately there doesn’t seem to be room for disagreement or controversy on climate change.  That is why scientists who disagree with the IPCC perspective are either retired, working in the private sector, or working for think tanks and other non-governmental organizations.

L’Eclaireur - Why did you leave academia and state funded research ?

Judith Curry - It became very clear to me that climate scientists can be successful only if they ‘play the game’ of supporting the IPCC consensus.  Activist scientists are rewarded with large laboratory spaces, institutes, high salaries, recognition from professional societies and lucrative financial awards from foundations.  Scientists will be marginalized or cancelled if they criticize the IPCC, challenge the IPCC conclusions, criticize the behavior and objectivity of activist climate scientists. I refused to ‘play the game’ and resigned my tenured university position. I am now working in the private sector as Présidente at the Climate Forecast Applications Network ¹.

L’Eclaireur - According to you, what drives the work of the IPCC ? Science or politics ?

Judith Curry - The charter for the IPCC is framed by politicians under the auspices of the UN. Scientists work within this narrow framing to focus on dangerous human caused climate change. This narrow framing marginalizes natural climate variability and ignores any benefits from a warmer climate.

L’Eclaireur - What's the impact of IPCC work on climate, as the Paris Agreement is only fulfilled by Gambia ?

Judith Curry - Global emissions continue to increase. Several industrial countries that are aggressively transitioning to wind and solar power, notably Germany, are finding that their energy is more expensive and less reliable, industries are leaving, and their economy is being damaged. Ironically, because Germany shut down its nuclear power plants and no longer has an abundant source of natural gas, Germany is returning to coal and its CO₂ emissions are increasing.

The lesson here is that nuclear power and natural gas are both good solutions for the energy transition, and that attempting to urgently reduce emissions with large-scale deployment of wind and solar is a recipe for both economic and environmental damage.

L’Eclaireur - Is there no other solution but reducing greenhouse gases' emissions ?

Judith Curry - We need to abandon the idea that we can control the climate by eliminating greenhouse gas emissions. Even if successful, we probably wouldn’t notice any change in the climate or extreme weather events in the 21^st century.  Pragmatic solutions focus on reducing local vulnerabilities to extreme weather and climate events, better water resource management, and research and development of better technologies to reduce our environmental footprint from electricity production, transportation, industry and agriculture.

1. CFAN, co-founded by Judith Curry, is a company that develops weather and climate forecasting tools and provides research and consulting services. Asked in 2010 about potential conflicts of interest, the climatologist admitted receiving funding from all sectors, including the fossil fuel industry. “My company has been making [short-term] hurricane forecasts for an oil company since 2007. During this period, I have been both a strong supporter of the IPCC and, more recently, a critic of the IPCC. There is no correlation between this funding and my public statements.”