Saturday, September 10, 2011

Beauty and change in nature's climate cycles

At the end of the Will Smith/Tommy Lee Jones movie “Men In Black” we see the camera back away from New York City until the planet Earth is visible from space, then the solar system and then the Milky Way galaxy come into view before we finally see that our whole galaxy is inside a marble ball in a game played by alien beings.  Part of the plot in the movie was the mission to prevent a galaxy that was inside a charm attached to a cat’s collar from falling into a bad-guy alien’s hands.  While light-hearted, this vision of the massive scale of reality recently hit home for me while I dedicated second thoughts to a fascinating book I had just read, “The Cooling Stars” by Henrik Svensmark and Nigel Calder (Icon Books, 2007).

Recent years have seen more climate research than in all prior years combined.  Prompted by prophets of doom like Al Gore, David Suzuki and the politicos on the UN International Panel on Climate Change (IPCC), serious scientists have been steadily breaking new ground.  Henrik Svensmark (Danish National Space Center) and others like Jan Veizer (geologist, University of Ottawa) and Nir Shaviv (astrophysicist, University of Jerusalem) have achieved a remarkable insight.  Since geological records on Earth show climate cycles of 135 million years alternating between icehouse (present) and hothouse, and this corresponds with no known phenomenon, it had to be caused by something outside Earth and our Sun.  They discovered a remarkably high correlation between cosmic rays reaching the Earth and global climate – so high this one critical factor explains 75% of temperature variation over the last 500 million years.

Cosmic rays matter because Svensmark’s theory and experiments have shown that when they collide with particles in our atmosphere and strip them of electrons, the ions thus created cause water droplet formation.  These droplets create low-level clouds, making the Earth whiter and reflecting more sunlight back into space.  More cosmic rays mean a cooler planet.  Two factors determine the level of cosmic rays reaching Earth: the strength of the Sun’s magnetic field (deflects rays) and our position in the Milky Way galaxy.  When the Sun burns more brightly there is naturally more sunlight reaching Earth, but it also deflects more cosmic rays, meaning there are less clouds – a reinforcing effect on global warming.  As our solar system travels around the galaxy, the spiral arms that are richer in the cosmic rays of the exploded suns of the galaxy are also spinning.  As we alternate between times within dense arms and relatively sparse spaces in between, the Earth cools and warms. 

So it turns out that almost all the variation in Earth’s climate can be explained by our varying orbit around the Sun, the cycles of the Sun’s radiation, and the travels of the Sun through the Milky Way galaxy.  Carbon dioxide has at best a very minor role to play in all this yet has been the focus of the most massive fear-driven propaganda campaign in history.  Veizer and Shaviv say that a doubling of CO2 would result in a temperature change of 0.75 degrees, matching the real-world satellite data of the last 30 years.
After reading Svensmark and Calder’s book, I closed my eyes and visualized the beautiful swirling spirals of the Milky Way galaxy for a minute, imagining them slowly rotating over hundreds of millions of years.  Next, I pictured a tiny solar system far away from the galactic center, its Sun pulsing like a faint firefly against a star-filled sky in the country, slowly making its way around the galaxy, visiting a star-rich spiral arm before spending time in relatively empty space between the arms.  Around that Sun is the tiny planet Earth, orbiting in a varying ellipse.  As the Earth’s orbit, tilt and wobble change, as the Sun’s light pulses and as it wends its way through the Milky Way the cloud cover waxes and wanes, cooling and warming the Earth and prompting species migration, adaptation and extinction.  Eventually the Sun will explode and send cosmic rays into the galaxy, sparking climate change on unknown worlds. 

To me it is a vision of beauty and wonder with the climate change cycles we worry so much about only minor notes in a very long symphony.  The more I learn about nature’s cycles the clearer I hear the symphony.  You might want to try lying back and listening too, as you emit much maligned carbon dioxide with every relaxed breath.

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