Attempt To Discredit Cosmic Ray-Climate Link Using Computer Model

Two computer modelers from CMU have written a program to simulate the interaction of cosmic rays with Earth's atmosphere. Because the model failed to predict significant increases in cloud cover, global warming activists are claiming the theory linking cosmic rays to climate change has been discredited. Climate models have failed to accurately predict the current downward trend in temperatures and now we are asked to accept a model as proof of how the Universe works. In truth, the paper cited is nothing more than a study of a computer program, and has nothing to do with the physical reality of how Earth's climate functions.

Appearing in Science under the title, “Study Challenges Cosmic Ray–Climate Link,” a review of the paper by Jeffrey Pierce and Peter Adams of Carnegie Mellon University in Pittsburgh, Pennsylvania, was used as an excuse to cast doubt on the theory that cosmic ray levels affect the creation of clouds in Earth's atmosphere. This theory was first proposed in 1997 by physicists Henrik Svensmark and Eigil Friis-Christensen of the Technical University of Denmark in Copenhagen. They reported that Earth's cloud cover seemed to vary in step with galactic cosmic rays—high-energy charged particles from outer space—striking Earth's atmosphere. The more cosmic rays, the more cloud cover, the more cloud cover the fewer warming rays from the sun reaching Earth's surface to affect the climate.

One of the reasons that the cosmic ray theory is so intriguing is that, to a significant extent, the sun's activity regulates the volume of particles impacting Earth, thus providing a mechanism for variation in the sun to affect earthly climate in ways other than irradiance (direct solar radiation). If Svensmark and Friis-Christensen's theory is correct, changes in solar activity are responsible for a large portion of climate variation, greatly diminishing the importance of greenhouse gases like CO2. This assault on climate change orthodoxy, combined with the fact that Svensmark and Friis-Christensen are not members of the climate change fraternity, have singled them out for attack by global warming true believers.

A study disproving the cosmic ray theory is perfectly plausible and an acceptable part of the way science works. When I first saw the title of the report in Science I was immediately excited. What cunningly conceived experiment had been devised to prove or, even harder, disprove the impact of cosmic rays on cloud formation? What finely reasoned logic allowed the researchers to separate the effects of cosmic rays from other influences and make this claim? After all, Svensmark and Nigel Marsh had shown the statistical correlation between galactic cosmic rays (GCR) and cloud cover in a study of satellite data published in the Journal of Geophysical Research – Atmospheres, in 2001. In it they stated, “The results presented here lend further support to the idea that at interannual timescales, solar variability has influenced low cloud [cover].”

Knowing that simply showing a statistical connection would be insufficent proof—there are many interesting correlations in nature that are not causally related—in a basement at the Danish National Space Center an experiment was set up to verify that cosmic rays could cause low level clouds to form under controlled conditions. The SKY Experiment used a cloud chamber to mimic conditions in the atmosphere. This included varying levels of background ionization and aerosol levels, and sulphuric acid (H2SO4), in particular. The SKY Experiment demonstrated that more ionization implies more particle nucleation. For a detailed writeup of the cosmic ray-climate connection please see The Resilient Earth, Chapter 11.

More evidence was published in a 2006 paper by Luis Eduardo Antunes Vieira and Ligia Alves da Silva of the Instituto Nacional de Pesquisas Espaciais, Brazil, entitled Geomagnetic modulation of clouds effects in the Southern Hemisphere Magnetic Anomaly through lower atmosphere cosmic ray effects. Studying cloud formation in the Southern Hemisphere they found: “The geomagnetic modulation of cloud effects in the net radiative flux in the atmosphere in the SHMA is, therefore, unambiguously due to GCRs and/or highly energetic solar proton particles effects.”

With preliminary experimental verification having been conducted in the SKY Experiment, CERN, the European Organization for Nuclear Research in Geneva, has decided to conduct more comprehensive verification in the CLOUD Project. This project has the backing of many institutions, from the California Institute of Technology to the Russian Academy of Sciences. A diagram of the proposed experimental apparatus is shown below.

The experiment comprises a 4 m diameter aerosol chamber and a 0.5 m diameter cylindrical cloud chamber which are exposed to an adjustable particle beam which simulates GCRs at any altitude or latitude. The chambers are filled with air, water vapor, trace gases and aerosols and can be operated at any temperature or pressure found in the terrestrial atmosphere. Each chamber contains an electric field cage to control the drift of small ions and charged aerosols while UV illumination allows photolytic reaction.

“The experiment has attracted the leading aerosol, cloud and solar-terrestrial physicists from Europe; Austria, Denmark, Finland, Germany, Switzerland and the United Kingdom are especially strong in this area” says the CLOUD spokesperson, Jasper Kirkby of CERN. Kirkby is shown below with a sketch illustrating the possible link between galactic cosmic rays and cloud formation. An interdisciplinary team from 18 institutes and 9 countries in Europe, the United States and Russia will perform the experiment. We will know if Svensmark is really on the right track when the CLOUD project starts producing data in 2011.

So you see, those who are doing real research on the subject of cosmic rays and climate are actually studying physical phenomena by constructing real experiments in order to take actual measurements—exactly what you would expect reputable scientists to do. Remember, they are attempting to establish the existence of new causal links, new phenomena that have not been considered previously by climate scientists. And here come Pierce and Adams' computer model, “a global atmospheric computer model of the sort used to model climate,” in a preemptive strike on real science using the same discredited techniques as the IPCC global warming cabal.

As Pierce and Adams report in their paper, in press in Geophysical Research Letters, their model showed that changes in cosmic rays are two orders of magnitude too feeble to cause the changes in clouds. “I'm feeling fairly confident that other models will also show the change in CCN is very weak,” Pierce remarked. “It's possible the models are missing something important; it just doesn't seem likely.”

Not to be left out, other climate change backers have have begun running similar global simulations of atmospheric particle formation, provoking a range of reactions. “We see a very similar thing”in our model, says Jan Kazil of the University of Colorado, Boulder. “Cosmic-ray variations have only a small effect on the clouds in our model.” Well, of course, the models are based on existing theory and fed with parameters selected by the modelers—what could go wrong with that?

What assumptions were made? What simplifications? What baseline data did they use to validate their model? The data yet to be collected by CLOUD? A model cannot be trusted to produce even remotely useful results without validation and even then they are often worse than useless. As an experienced computer modeler I can tell you that models can be hyper sensitive to the smallest of changes to seemingly innocuous parameters. I am not alone in casting doubt on the veracity of the modeler's claims, Fangqun Yu of the University at Albany in New York says he disagrees with the Carnegie Mellon researchers “because of problems in their simulations.” That's putting it mildly.

This is not real science, it is a parlor trick, a conjuring act using computer software to summon up meaningless data that are then spun into “facts” used to dismiss out of hand an inconvenient competing theory. A more truthful title to the report would have been “Computer Model Fails To Establish Cosmic Ray – Climate Link.” This model proves nothing about the real world.

It is one thing to construct a model as a way to gain insight to a larger investigation, I do not fault Pierce and Adams for that. I do hold them and the journals who have reported their results as scientifically significant in contempt as climate change spin doctors, on the same level as Gore and Hansen. As Wolfgang Pauli famously said of a paper submitted by a colleague, “This isn't right. This isn't even wrong.” To that I will add this is not science and it sure as hell isn't proof.

Be safe, enjoy the interglacial and stay skeptical.

The photo of the earth facing

The photo of the earth facing the cosmic rays from the sun is really awesome and I must appreciate the artwork done by the artist in this picture.

Cosmic radiation causes fluctuations in global temperatures

(—Unlike electromagnetic radiation, which consists of massless and accelerated charged particles, galactic cosmic rays (CR) are composed mostly of atomic nuclei and solitary electrons, objects that have mass. Cosmic rays originate via a wide range of processes and sources including supernovae, galactic nuclei, and gamma ray bursts. Researchers have speculated for decades on the possible effects of galactic cosmic rays on the immediate environs of Earth's atmosphere, but until recently, a causal relationship between climate and cosmic rays has been difficult to establish.

A research collaborative has published a paper in the Proceedings of the National Academy of Sciences that mathematically establishes such a causal link between CR and year-to-year changes in global temperature, but has found no causal relationship between the CR and the warming trend of the 20th century.

New Paper: Cosmic Ray Decreases Affect Clouds

Henrik Svensmark et al. have a new GRL paper in press entitled “Cosmic ray decreases affect atmospheric aerosols and clouds,” that give empirical evidence cosmic rays affect climate. The Abstract states:

Close passages of coronal mass ejections from the sun are signaled at the Earth's surface by Forbush decreases in cosmic ray counts. We find that low clouds contain less liquid water following Forbush decreases (FDs), and for the most influential events the liquid water in the oceanic atmosphere can diminish by as much as 7%. Cloud water content as gauged by the Special Sensor Microwave/Imager (SSM/I) reaches a minimum around 7 days after the Forbush minimum in cosmic rays, and so does the fraction of low clouds seen by the Moderate Resolution Imaging Spectroradiometer (MODIS) and in the International Satellite Cloud Climate Project (ISCCP). Parallel observations by the aerosol robotic network AERONET reveal falls in the relative abundance of fine aerosol particles which, in normal circumstances, could have evolved into cloud condensation nuclei (CCN). Thus a link between the sun, cosmic rays, aerosols, and liquid-water clouds appears to exist on a global scale.

The paper concludes:

Our results show global-scale evidence of conspicuous influences of solar variability on cloudiness and aerosols. Irrespective of the detailed mechanism, the loss of ions from the air during FDs reduces the cloud liquid water content over the oceans. So marked is the response to relatively small variations in the total ionization, we suspect that a large fraction of Earth's clouds could be controlled by ionization. Future work should estimate how large a volume of the Earth's atmosphere is involved in the ion process that leads to the changes seen in CCN and its importance for the Earth's radiation budget. From solar activity to cosmic ray ionization to aerosols and liquid-water clouds, a causal chain appears to operate on a global scale.

Svensmark, H., T. Bondo, and J. Svensmark (2009),
Cosmic ray decreases affect atmospheric aerosols and clouds,
Geophys. Res. Lett., doi:10.1029/2009GL038429, in press.
(accepted 17 June 2009)

Good work, Doug

Your article makes so much more sense than the one at the Science Daily ( They seemed to be so occupied with jumping with glee that they overlooked the substance of the Carnegie Mellon study.
-Robert Moen

ScienceDaily article

I just scanned the post on They called the cosmic ray theory "a troubling hypothesis about how the sun may impact global warming" and claimed that it "is finally laid to rest." Of course they are just reporting third hand what Science reported second hand—spin on top of spin. No wonder the public is confused and misinformed.

This is confusing

So modelers are saying that an effect that wasn't put into the model doesn't exist because it isn't in the model? How can this be anything but circular reasoning?

I only did enough computer modeling as an undergrad Chemical Engineer to know how easy it is to get nonsensical conclusions. This isn't science, and I agree with the conclusion by adding the final line that Pauli never said.

This isn't right
It isn't wrong
It's just stupid.

Clouds and Cosmic Rays

Our understanding of cloud formation, and cloud microphysics is not yet sufficient to construct such models. Even the IPCC 2007 rates the LOSU (Level of Scientific Understanding) for clouds as Low. In fact this is thought to be the achilles heel in the global warming hypothesis by those who study clouds and climate sensitivity. At best, such models can be used for sensitivity studies, but not for projections or physical proof. Keep in mind, a model is itself a hypothesis.

Data versus AGW theory...

Since the Hockey Stick was rubbished, and the "proof" that the 1990s were uniquely the hottest decade in human history - the global warming field as devolved back into a debate between data driven realists, and theory driven alarmists.

For the latter, theory trumps the real world, and data can be 'safely' ignored. For the former, science is not settled because the most relevant data is still coming in. Data, for instance, bearing on natural mechanisms of climate variability. The IPCC is disingenuous in marginalizing solar and land use changes, and, in the latter case, promoting science fraud instead of exposing it.

For lovers of Truth who respect science, these are dark days indeed.

my two cents (from Peter Adams)

Doug questioned our modeling study:

"What assumptions were made? What simplifications?"

Many of the commenters in this forum have criticized the paper on the grounds that a computer simulation of physics we don't understand cannot have any value. Our paper is more nuanced than that.

The key assumptions and simplifications Doug asks about are discussed in the paper, but let me recap as follows. The cosmic ray-cloud hypothesis involves a number of steps in the chain of cause and effect but can be broken down as follows:

1) Changes in solar cycle and cosmic rays change the formation of small particle nuclei (approx 1 nm diameter) in the atmosphere
2) The small particles must then grow quite a lot (to about 100 nm diameter) before they can affect clouds

Of course, if the physical processes in either part are weak, then they hypothesis fails.

Now, Pierce and I completely agree that part (1) is very poorly understood. On the other hand, part (2), particle growth, is pretty well understood - the physics boil down to condensation and coagulation - processes that are ultimately just diffusion. This is the part we examined quantitatively.

Since part (1) is poorly understood, we made every attempt to give the hypothesis full benefit of the doubt. First, at the time of our study, there was only one theory for ion-induced nucleation that was suitable for use in a global model, so of course we used that as a starting point. Second, to give full benefit of the doubt, we performed an additional simulation in which every ion forms a particle. We consider this to be an "upper bound" on how big part (1) could be. I met a nice member of Svenmark's research group at a conference, showed him our results, and made a standing offer that, we would be happy to run additional simulations of any part (1) scenario that they thought was plausible. If they have a larger estimate of how big the part (1) effect could be, we are still more than happy to run that scenario and help them demonstrate it.

So the gist of our paper can be summarized as follows "Let's make part (1) as strong as possible and use known physics to simulate part (2). If this upper bound is not big enough to be important to climate, this really hurts the cosmic ray-cloud hypothesis." At the very least, it shifts the burden of proof to the proponents to build a plausible model in which the effect is big enough to matter.

A few cents more


Thank you for your detailed and cogent response to my editorial regarding your effort to model cosmic ray induced nucleation and cloud formation. As you noted, there was not enough detail given about the assumptions made in the review articles (mine included) even though they were clearly stated in your actual paper. Please understand that my main complaint about the reporting of the paper was not your work itself, or even the assumptions that work was based on, it was with the tone of the articles that reported your work and a lack of detail that would have helped the public understand its significance.

I do agree that the burden of proving the cosmic ray-cloud hypothesis lies clearly with its proponents. As my article points out, experiments have been designed and a rigorous investigation undertaken to provide better information regarding the first part of the causal chain. It will be from those efforts that positive results will strengthen or negative results will weaken the hypothesis. Your attempt to establish a hypothetical upper bound, as you stated, is a useful exercise, but it doesn't provide acceptable proof that the cosmic ray hypothesis is discredited. It could help guide those performing real world experiments, which is precisely how modeling should be used when the underlying science is not well evolved.

The Science commentary said: “Until now, the debate over cosmic rays and climate has dwelt more on wavy lines on graphs than on state-of-the-art global modeling.” This gives the distinct impression that observational data (i.e. wavy lines on graphs) are of no consequence but that constructing a model, based on the poorly understood physical process of ion-induced nucleation, is a substitute for actually observing nature. As an experimental computer scientist myself, I take strong exception to attempts to oversell modeling, promoting it as a substitute for doing science in the real world. I think that the improper characterization of models as in some way better than messy real world science, overstating the level of “proof” that they provide, is damaging to the field. Models provide numbers, numbers can provide insight—claims beyond that are dubious at best.

Amen to that, Doug!

I agree 100% with your position. What has happened to real science? If the data does not fit the model, how is it that the data is wrong? If the data does not fit then the model must be wrong! After all it's just a model!

Dr. Steve