Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cosmic Rays Are Not the Cause of Climate Change, Scientists Say

22.01.2004

Eleven Earth and space scientists say that a recent paper attributing most climate change on Earth to cosmic rays is incorrect and based on questionable methodology. Writing in the January 27 issue of Eos, published by the American Geophysical Union, Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research and colleagues in Canada, France, Germany, Switzerland, and the United States challenge the cosmic ray hypothesis.

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 a 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. Volcanic eruptions, changes in solar activity, and the concentration of greenhouse gases, as well as internal oscillations of the climate system, are crucial on this scale.

The 11 authors of the Eos article affirm that the strong increase of carbon dioxide and some other greenhouse gases in the atmosphere due to manmade emissions is most probably the main cause of the global warming of the last few decades. The most important physical processes are well understood, they say, and model calculations as well as data analyses both come to the conclusion that the human contribution to the global warming of the 20th century was dominant.

Harvey Leifert | AGU
Further information:
http://www.agu.org

More articles from Earth Sciences:

nachricht Research sheds new light on forces that threaten sensitive coastlines
24.04.2017 | Indiana University

nachricht NASA sees the end of ex-Tropical Cyclone 02W
21.04.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>