Svensmark: ‘Evidence of nearby supernovae affecting life on Earth’ (Re. Climate Change)

I explained the basics of the cosmoclimatology theory before as part of my list of reasons “Why I Question the CO2-driven Global Warming “Scientific Consensus”“.  On that fascinating science topic, the British science writer Nigel Calder has an incredibly interesting story on his blog today (my emphasis): http://calderup.wordpress.com/2012/04/24/a-stellar-revision-of-the-story-of-life/

A Stellar Revision of the Story of Life –  Svensmark’s Cosmic Jackpot.’
Climate Change: News and Comments and The Svensmark Hypothesis

Visible to the naked eye as the Seven Sisters, the Pleiades are the most famous of many surviving clusters of stars that formed together at the same time. The Pleiades were born during the time of the dinosaurs, and the most massive of the siblings would have exploded over a period of 40 million years. Their supernova remnants generated cosmic rays. From the catalogue of known star clusters, Henrik Svensmark has calculated the variation in cosmic rays over the past 500 million years, without needing to know the precise shape of the Milky Way Galaxy. Armed with that astronomical history, he digs deep into the histories of the climate and of life on Earth. Image ESA/NASA/Hubble.

Today the Royal Astronomical Society in London publishes (online) Henrik Svensmark’s latest paper entitled “Evidence of nearby supernovae affecting life on Earth”.

After years of effort Svensmark shows how the variable frequency of stellar explosions not far from our planet has ruled over the changing fortunes of living things throughout the past half billion years. Appearing in Monthly Notices of the Royal Astronomical Societyit’s a giant of a paper, with 22 figures, 30 equations and about 15,000 words. See the RAS press release at http://www.ras.org.uk/news-and-press/219-news-2012/2117-did-exploding-stars-help-life-on-earth-to-thrive

By taking me back to when I reported the victory of the pioneers of plate tectonics in their battle against the most eminent geophysicists of the day, it makes me feel 40 years younger. Shredding the textbooks, Tuzo Wilson, Dan McKenzie and Jason Morgan merrily explained earthquakes, volcanoes, mountain-building, and even the varying depth of the ocean, simply by the drift of fragments of the lithosphere in various directions around the globe.

In Svensmark’s new paper an equally concise theory, that cosmic rays from exploded stars cool the world by increasing the cloud cover, leads to amazing explanations, not least for why evolution sometimes was rampant and sometimes faltered. In both senses of the word, this is a stellar revision of the story of life.

Here are the main results:

  • The long-term diversity of life in the sea depends on the sea-level set by plate tectonics and the local supernova rate set by the astrophysics, and on virtually nothing else.
  • The long-term primary productivity of life in the sea – the net growth of photosynthetic microbes – depends on the supernova rate, and on virtually nothing else.
  • Exceptionally close supernovae account for short-lived falls in sea-level during the past 500 million years, long-known to geophysicists but never convincingly explained..
  • As the geological and astronomical records converge, the match between climate and supernova rates gets better and better, with high rates bringing icy times.

Presented with due caution as well as with consideration for the feelings of experts in several fields of research, a story unfolds in which everything meshes like well-made clockwork. Anyone who wishes to pooh-pooh any piece of it by saying “correlation is not necessarily causality” should offer some other mega-theory that says why several mutually supportive coincidences arise between events in our galactic neighbourhood and living conditions on the Earth.

An amusing point is that Svensmark stands the currently popular carbon dioxide story on its head. Some geoscientists want to blame the drastic alternations of hot and icy conditions during the past 500 million years on increases and decreases in carbon dioxide, which they explain in intricate ways. For Svensmark, the changes driven by the stars govern the amount of carbon dioxide in the air. Climate and life control CO2, not the other way around.

By implication, supernovae also determine the amount of oxygen available for animals like you and me to breathe. So the inherently simple cosmic-ray/cloud hypothesis now has far-reaching consequences, which I’ve tried to sum up in this diagram.

Cosmic rays in action. The main findings in the new Svensmark paper concern the uppermost stellar band, the green band of living things and, on the right, atmospheric chemistry. Although solar modulation of galactic cosmic rays is important to us on short timescales, its effects are smaller and briefer than the major long-term changes controlled by the rate of formation of big stars in our vicinity, and their self-destruction as supernovae. Although copyrighted, this figure may be reproduced with due acknowledgement in the context of Henrik Svensmark’s work.

By way of explanation

The text of  Svensmark’s 2012 article,“Evidence of nearby supernovae affecting life on Earth”, is available via  ftp://ftp2.space.dtu.dk/pub/Svensmark/MNRAS_Svensmark2012.pdf 

The paper is highly technical, as befits a professional journal, so to non-expert eyes even the illustrations may be a little puzzling. [...]”   Continue reading on Nigel Calder’s blog, where the graphs are explained in easy to understand ways.

[h/t to WUWT, here.]

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2 Responses to Svensmark: ‘Evidence of nearby supernovae affecting life on Earth’ (Re. Climate Change)

  1. Pingback: My Question at 38,000 feet Altitude near Greenland: How’s the ice doing? | Not all alleged is apparent…

  2. Pingback: Global Cooling ahead? (w/ Global Annual Average Temperature Anomalies, Ocean Heat Content mystery, Solar Cycle 24-25,…) | Not All Alleged Is Apparent…

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