Cosmic Rays Dismissed

This item goes a long way toward eliminating cosmic rays as a climate variable. It is sort of nice to know that we can eliminate at least one such variable. This is yet another case were improved resolution knocks out an attractive conjecture. Certainly the possibility of a correlation existed here and the lack of such is extremely convincing. We will not hear from this theory again.

MODIS data: cosmic rays do not explain global warming

December 24, 2008--The Moderate Resolution Imaging Spectroradiometer (MODIS), a spectral instrument built by Raytheon (El Segundo, CA) and sent into space on the Earth Observing System (EOS) Terra and Aqua satellites, has provided data for a new study that supports earlier findings by stating that changes in cosmic rays most likely do not contribute to climate change.

It has sometimes been claimed that changes in radiation from space--galactic cosmic rays--can be one of the causes of global warming. The new study, which investigates the effect of cosmic rays on clouds, concludes that the likelihood of this is very small.

The study, "Cosmic rays, cloud condensation nuclei and clouds--a reassessment using MODIS data," was recently published in the journal Atmospheric Chemistry and Physics. A group of researchers from the University of Oslo (Oslo, Norway), the Norwegian Institute for Air Research (Kjeller, Norway), the CICERO Center for Climate and Environmental Research (Oslo, Norway), and the University of Iceland (Reykjavik, Iceland) are behind the study.

The MODIS instrument has an off-axis telescope with a 17.78-cm-diameter aperture and provides image data in 36 spectral bands, ranging from 620 to 670 nm (band 1) to 14.085 to 14.385 microns (band 36). The instrument can reach a peak daytime data rate of 11 Mbit/s and draws an average of 150 W of electrical power.

Cosmic rays unlikely to affect warming

There are scientific uncertainties about cosmic rays and cloud formation. Some researchers have claimed that a reduction of cosmic rays during the last decades has contributed to the global temperature rise. The hypothesis is that fewer cosmic rays causes fewer cloud droplets and reduced droplet size, and that this again causes global warming, since reduced cloud droplets would reflect less energy from the sun back to space. However, the researchers who stick to this hypothesis find little support amongst colleagues.

"According to our research, it does not look like reduced cosmic rays leads to reduced cloud formation," says Jon Egill Kristjansson, a professor at the University of Oslo.

This result is in line with most other research in the field. As far as Kristjansson knows, no studies have proved a correlation between reduced cosmic rays and reduced cloud formation. Kristjansson also points out that most research shows no reduction in cosmic rays during the last decades, and that an astronomic explanation of today's global warming therefore seems very unlikely.

Data from solar outbreaks

Kristjansson and his colleagues have used observations from so-called Forbush decrease events: Sudden outbreaks of intense solar activity that lead to a strong reduction of cosmic rays, lasting for a couple of days. The researchers have identified 22 such events between 2000 and 2005.

Based on data from the spaceborne MODIS instrument, the researchers have investigated whether these events have affected cloud formation. While previous studies have mainly considered cloud cover, the high spatial and spectral resolution of the MODIS data also allows for a more thorough study of microphysical parameters such as cloud droplet size, cloud water content and cloud optical depth. No statistically significant correlations were found between any of the four cloud parameters and galactic cosmic rays.

"Reduced cosmic rays did not lead to reduced cloud formation, either during the outbreaks or during the days that followed. Indeed, following some of the events we could see a reduction, but following others there was an increase in cloud formation. We did not find any patterns in the way the clouds changed," says Kristjansson.

By focusing on pristine Southern Hemisphere ocean regions, the researchers examined areas where a cosmic-ray signal should be easier to detect than elsewhere.

Supports other recent work

Joanna Haigh from Imperial College London has also studied possible links between solar variability and modern-day climate change. "This is a careful piece of work by Jon Egill Kristjansson that appears to find no evidence for the reputed link between cosmic rays and clouds," she commented to BBC. "It's supporting other recent work that also found no relationship."

posted by John Wallace

Svenmark Cosmic Ray Experiment

I have just come across this item from last year but it must be considered. It has been demonstrated in lab conditions that ambient cosmic ray flux generates the precursors for cloud formation. We get no sense from this as yet regarding what percentage this represents of the cloud cover.

We learn that the combining of water and sulphuric acid is a necessary precursor to cloud formation and that liberation of electrons by cosmic rays drives the process or at least that is the reasonable inference.

At least we can also now link pollution to its potential climatic effects a little better.

Assuming that variation in the sun’s activity level affects Earth’s Magnetic field we have a natural force multiplier that needs to be properly mapped and whose effects need to be modeled and confirmed if that is ever possible.

I share Nigel’s frustration with the state of scientific literacy in the press.

When I began this blog, I commented that I expected the proponents of the CO2 – Global Warming linkage hypothesis to be made fools of by Mother Nature. Both phenomena are very important and demand responses. The problem was always in the linkage idea. It was simply the introduction of an unnecessary extra theory that could cause problems for the real issues. And it was not necassary.

The linkage hypothesis has been dust for ten years and we are now facing major indicators pointing the other way.



February 11, 2007

An experiment that hints we are wrong on climate change

Nigel Calder, former editor of New Scientist, says the orthodoxy must be challenged


When politicians and journalists declare that the science of global warming is settled, they show a regrettable ignorance about how science works. We were treated to another dose of it recently when the experts of the Intergovernmental Panel on Climate Change issued the Summary for Policymakers that puts the political spin on an unfinished scientific dossier on climate change due for publication in a few months’ time. They declared that most of the rise in temperatures since the mid-20th century is very likely due to man-made greenhouse gases.

The small print explains “very likely” as meaning that the experts who made the judgment felt 90% sure about it. Older readers may recall a press conference at Harwell in 1958 when Sir John Cockcroft, Britain’s top nuclear physicist, said he was 90% certain that his lads had achieved controlled nuclear fusion. It turned out that he was wrong. More positively, a 10% uncertainty in any theory is a wide open breach for any latter day Galileo or Einstein to storm through with a better idea. That is how science really works.

Twenty years ago, climate research became politicized in favour of one particular hypothesis, which redefined the subject as the study of the effect of greenhouse gases. As a result, the rebellious spirits essential for innovative and trustworthy science are greeted with impediments to their research careers. And while the media usually find mavericks at least entertaining, in this case they often imagine that anyone who doubts the hypothesis of man-made global warming must be in the pay of the oil companies. As a result, some key discoveries in climate research go almost unreported.

Enthusiasm for the global-warming scare also ensures that heat waves make headlines, while contrary symptoms, such as this winter’s billion-dollar loss of Californian crops to unusual frost, are relegated to the business pages. The early arrival of migrant birds in spring provides colourful evidence for a recent warming of the northern lands. But did anyone tell you that in east Antarctica the Adélie penguins and Cape petrels are turning up at their spring nesting sites around nine days later than they did 50 years ago? While sea-ice has diminished in the Arctic since 1978, it has grown by 8% in the Southern Ocean.

Bottom of Form

So one awkward question you can ask, when you’re forking out those extra taxes for climate change, is “Why is east Antarctica getting colder?” It makes no sense at all if carbon dioxide is driving global warming. While you’re at it, you might inquire whether Gordon Brown will give you a refund if it’s confirmed that global warming has stopped. The best measurements of global air temperatures come from American weather satellites, and they show wobbles but no overall change since 1999.

That leveling off is just what is expected by the chief rival hypothesis, which says that the sun drives climate changes more emphatically than greenhouse gases do. After becoming much more active during the 20th century, the sun now stands at a high but roughly level state of activity. Solar physicists warn of possible global cooling, should the sun revert to the lazier mood it was in during the Little Ice Age 300 years ago.

Climate history and related archeology give solid support to the solar hypothesis. The 20th-century episode, or Modern Warming, was just the latest in a long string of similar events produced by a hyperactive sun, of which the last was the Medieval Warming.

The Chinese population doubled then, while in Europe the Vikings and cathedral-builders prospered. Fascinating relics of earlier episodes come from the Swiss Alps, with the rediscovery in 2003 of a long-forgotten pass used intermittently whenever the world was warm.

What does the Intergovernmental Panel do with such emphatic evidence for an alternation of warm and cold periods, linked to solar activity and going on long before human industry was a possible factor? Less than nothing. The 2007 Summary for Policymakers boasts of cutting in half a very small contribution by the sun to climate change conceded in a 2001 report.

Disdain for the sun goes with a failure by the self-appointed greenhouse experts to keep up with inconvenient discoveries about how the solar variations control the climate. The sun’s brightness may change too little to account for the big swings in the climate. But more than 10 years have passed since Henrik Svensmark in Copenhagen first pointed out a much more powerful mechanism.

He saw from compilations of weather satellite data that cloudiness varies according to how many atomic particles are coming in from exploded stars. More cosmic rays, more clouds. The sun’s magnetic field bats away many of the cosmic rays, and its intensification during the 20th century meant fewer cosmic rays, fewer clouds, and a warmer world. On the other hand the Little Ice Age was chilly because the lazy sun let in more cosmic rays, leaving the world cloudier and gloomier.

The only trouble with Svensmark’s idea — apart from its being politically incorrect — was that meteorologists denied that cosmic rays could be involved in cloud formation. After long delays in scraping together the funds for an experiment, Svensmark and his small team at the Danish National Space Center hit the jackpot in the summer of 2005.

In a box of air in the basement, they were able to show that electrons set free by cosmic rays coming through the ceiling stitched together droplets of sulphuric acid and water. These are the building blocks for cloud condensation. But journal after journal declined to publish their report; the discovery finally appeared in the Proceedings of the Royal Society late last year.

Thanks to having written The Manic Sun, a book about Svensmark’s initial discovery published in 1997, I have been privileged to be on the inside track for reporting his struggles and successes since then. The outcome is a second book, The Chilling Stars, co-authored by the two of us and published next week by Icon books. We are not exaggerating, we believe, when we subtitle it “A new theory of climate change”.

Where does all that leave the impact of greenhouse gases? Their effects are likely to be a good deal less than advertised, but nobody can really say until the implications of the new theory of climate change are more fully worked out.

The reappraisal starts with Antarctica, where those contradictory temperature trends are directly predicted by Svensmark’s scenario, because the snow there is whiter than the cloud-tops. Meanwhile humility in face of Nature’s marvels seems more appropriate than arrogant assertions that we can forecast and even control a climate ruled by the sun and the stars.