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[InfiniteNow]

Originally Posted by Turtle

Of course, many scientists have well-reasoned skeptical views on anthropogenic CO2. To whit:

The real deal?

Where have Nir Shariv's studies been published? I find ZERO studies of his online. Seems like more handwaving, smoke, and mirrors.

Prove me wrong. Please.


EDIT: Looks like the article to which Turt linked us misspelled his name throughout. A quick search with proper spelling (Nir Shaviv) turned up the following:


:: SCRIPPS OCEANOGRAPHY NEWS : : Cosmic Rays are Not the Cause of Climate Change, Scientists Say ::

In July 2003, astrophysicist Nir Shaviv and geologist Jan Veizer wrote in GSA Today that they had established a correlation between cosmic rays and temperature evolution over hundreds of millions of years. They also claimed that current global warming is not primarily caused by human emissions of carbon dioxide. Their findings have been widely reported in international news media.

According to Rahmstorf, Shaviv and Veizer's analyses-and especially their conclusions-are scientifically ill-founded. The data on cosmic rays and temperature so far in the past are extremely uncertain, he says. Further, their reconstruction of ancient cosmic rays is based on only 50 meteorites, and most other experts interpret their significance in a very different way, he says. He adds that two curves presented in the article show an apparent statistical correlation only because the authors adjusted the data, in one case by 40 million years. In short, say the authors of the Eos article, Shaviv and Veizer have not shown that there is any correlation between cosmic rays and climate.

As for the influence of carbon dioxide in climate change, many climatologists were surprised by Shaviv and Veizer's claim that their results disproved that current global warming was caused by human emissions, Rahmstorf says.

Even if their analysis were methodologically correct, their work applied to time scales of several million years.

The current climate warming has, however, occurred during just the past one hundred years, for which completely different mechanisms are relevant, he says. For example, over millions of years, the shifting of continents influences climate, while over hundreds of thousands of years, small changes in Earth's orbit can initiate or terminate ice ages. But for time periods of years, decades, or centuries, these processes are irrelevant.

EDIT2: A more full rebuttal (conclusion only below, please click the link to see the details. It matters):


Cosmic Rays, Carbon Dioxide and Climate: Rebuttal of Shaviv and Veizer

Two main conclusions result from our analysis of [Shaviv and Veizer, 2003]. The first is that the correlation of cosmic ray flux (CRF) and climate over the past 520 m.y. appears to not hold up under scrutiny. Even if we accept the questionable assumption that meteorite clusters give information on CRF variations, we find that the evidence for a link between CRF and climate amounts to little more than a similarity in the average periods of the CRF variations and a heavily smoothed temperature reconstruction. Phase agreement is poor. The authors applied several adjustments to the data to artificially enhance the correlation. We thus find that the existence of a correlation has not been convincingly demonstrated.

Our second conclusion is independent of the first. Whether there is a link of CRF and temperature or not, the authors’ estimate of the effect of a CO2-doubling on climate is highly questionable. It is based on a simple and incomplete regression analysis which implicitly assumes that climate variations on time scales of millions of years, for different configurations of continents and ocean currents, for much higher CO2 levels than at present, and with unaccounted causes and contributing factors, can give direct quantitative information about the effect of rapid CO2 doubling from pre-industrial climate. The complexity and non-linearity of the climate system does not allow such a simple statistical derivation of climate sensitivity without a physical understanding of the key processes and feedbacks. We thus conclude that [Shaviv and Veizer, 2003] provide no cause for revising current estimates of climate sensitivity to carbon dioxide.

EDIT3: Nir Shaviv is also debunked here:

RealClimate » Fun with correlations!




Shall I continue?