Posted on 01/27/2004 3:16:24 PM PST by blam
'No cosmic ray climate effects'
By Alex Kirby
BBC News Online environment correspondent
Clouds' role in climate change remains contested
The principal cause of recent climate change is not cosmic rays but human activities, a group of scientists says. They say an article last year linking cosmic rays and changes in temperature was "scientifically ill-founded".
They say the authors' methods were open to doubt and their conclusions wrong, surprising experts with their claims.
In Eos, the journal of the American Geophysical Union, the 11 Earth and space scientists insist that greenhouse gases remain the chief climate suspect.
In the climate mainstream
They say the most important physical processes are well understood, and model calculations and data analyses both conclude the human contribution to the global warming of the 20th Century through increased emissions of carbon dioxide (CO2) and other gases was dominant.
The authors of the Eos article - Cosmic Rays, Carbon Dioxide And Climate - are from Canada, France, Germany, Switzerland and the US.
COSMIC RAYS AND CLOUDS
* The Sun's magnetic field and solar wind shield the Solar System from cosmic rays (very energetic particles and radiation from outer space)
* Changes in solar activity will affect the performance of the shield and how many cosmic rays get through to Earth
* Theory suggests cosmic rays can "seed" clouds. Some satellite data have shown a close match between the amount of cloud cover over Earth and the changing flux in cosmic rays reaching the planet
The research by Nir Shaviv, an astrophysicist, of Hebrew University in Jerusalem, and Jan Veizer, a geologist, of the University of Ottawa and Ruhr University in Germany, was published in July 2003 in the Geological Society of America's journal GSA Today.
It said the Earth's climate was profoundly affected by cosmic rays, high-energy particles from outer space, which normally cool the Earth's surface by helping clouds to form.
But increased solar activity lessens the cosmic rays reaching the Earth, and Shaviv and Veizer suggested this blocking effect had been the dominant cause of global warming over the past century.
No ground given
They said cosmic ray changes accounted for at least 66% of the temperature variation during that period.
The Eos team says humans affect climate more than clouds
The Eos authors, led by Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research, Germany, say the paper by Shaviv and Veizer was "incorrect and based on questionable methodology".
They say the data on cosmic rays and temperature so far in the past are extremely uncertain.
They argue that the authors' reconstruction of ancient cosmic rays is based on only 50 meteorites, and say most other experts interpret their significance in a very different way.
Arguing that Shaviv and Veizer had in places adjusted the data, "in one case by 40 million years", the Eos team says they did not show any correlation between cosmic rays and climate.
And even if their analysis had been methodologically correct, it says, their work applied to time scales of several million years, while the current climate warming has occurred during just a hundred years, for which completely different mechanisms are relevant.
Dr Shaviv told BBC News Online: "The article in Eos raises general claims without substantiating them with any actual evidence. The few more specific arguments that they bring are simply flawed and easily refuted."
Professor Veizer told BBC News Online: "It's a long story, and the whole issue is politically driven.
"We stand by what we said, that there is a correlation between the cosmic ray flux and the temperatures we calculated, though on the details we can disagree."
Well that settles it. The only way to save the world is for America to give up Her wealth and for a people's democratic republic to be established here. The scientists' computer says it's our fault. Sorry.
They also pointed out that a separate report identifying capitalist free market solutions to environmental problems was also flawed.
Global warming is real and proven and global socialism is the only solution. Anyone who says otherwise needs to spend more time in the re-education camps.
Yes, it is a gas and it has a profound effect on climate and temperature.
Dry air is a fairly good thermal insulator and doesn't hold heat worth a hoot, but water molecules can hold more heat per unit of weight thatn any other substance.
People who use humidifiers in the winter can tell you that the increased water vapor in the air (humidity) allows a house to hold its heat more efficiently than when the air is dry. It is very noticeable.
The models are still unable to deal with it.
Until they can, they have no business making statements regarding the other greenhouse gases which play a much smaller role.
Clouds are part of their problem as the models can't handle them either. That leaves them in a position of trying to convince people that clouds don't effect the climate....DUH!
Happy to help out where ever I can.
They say the authors' methods were open to doubt and their conclusions wrong, surprising experts with their claims.
Too bad for these supposed "scientists" that cloud measurements today, not just the inferences from the Paleologic record of Shaviv and Veizer, support Solar modulated cosmic ray influence over the climate of as much as four times the effect of variation in solar intensities alone.
In short the IPCC's models fail again against real data.
http://www.tmgnow.com/repository/global/CREC.html
FIG. I. Composite figure showing changes in Earth's cloud cover from four satellite cloud data sets together with cosmic ray fluxes from Climax (solid curve, normalized to May 1965) and 10.7 cm solar Bur (dashed curve, in units of 10-22 Wm-2 Hz-2). Triangles are the Nimbus7 data, squares are the ISCCP C2 and ISCCP_D2 data, diamonds are the DMSP data. All of the displayed data have been smoothed using a 12 month running mean. The Nimbus7 is for the southern hemisphere over oceans with the tropics excluded. The DMSP data are total cloud cover for the southern hemisphere over oceans, and finally the ISCCP data have been derived from geostationary satellites over oceans with the tropics excluded. Also shown are 2-standard-deviation error bars for the three data sets, one for each 6 months.
"From Svensmark and Friis-Christensen [7] it is known that from 1987 to 1990 global cloudiness changed approximately 3.0% which can be estimated to be 1.50 W/mZ [7]. In the same period cosmic rays from the ion chamber changed 3.5% as seen in Fig. 2. We can now calculate the approximate radiative forcing by noting that the mean 11 year average increase of cosmic rays in Fig. 3 from 1975 to 1989 is 1.2%, which then corresponds to a possible 0.5 W/m2 change in cloud forcing. This is a fairly large forcing, about 4 times the estimated change in solar irradiance. The resulting temperature change is difficult to estimate exactly. Studies obtained from a general circulation model gave a sensitivity (0.7 to I'C/Wm-2 for DS =0.25%, where S is the solar constant) [26]. The direct influence of changes in solar irradiance is estimated to be only 0.1'C [6]. The cloud forcing, however, gives for the above sensitivity, 0.3-0.5'C, and has therefore the potential of explaining nearly all of the temperature changes in the period studied. "
So what causes global dimming? The first thing to say is that it's nothing to do with changes in the amount of radiation arriving from the sun. .....the global dimming effect is much, much larger and the opposite of what would be expected given there has been a general increase in overall solar radiation over the past 150 years.
It appears that (a) the solar output has been increasing, as I asserted, (b) there has been an even higher level of absorption by clouds or particulates, causing both global warming and 'solar dimming'.
What causes the dimming? Increased cloud-coverage from greater water evaporation, due to the higher temperatures? Particulates, due to diesel engines, for example?
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