Are we about to be dethroned again?

kw: observations, climate change

Thinking about the recent books I reviewed on the climate change debate, I remembered history. Since the 15th century, the human race has lost a lot of its purported luster.

From Biblical times to the time of Copernicus and Galileo, at least in the West, humanity was seen as "the image of God", ruling a world around which all the universe revolved. A few discoveries rocked that cozy world-view:

• Copernicus showed that Earth was not the center of the Universe, but revolved about the Sun. But maybe the Sun was the center?
• Kepler showed that planetary orbits, Earth's included, were ellipses (slightly distorted by the influence of other planets), rather than perfect circles as taught by Authority.
• Galileo's successors, with telescopes plus better and better clocks, showed that the Sun was a million times the mass of the earth, and that the bright planets Jupiter and Saturn were themselves more than 100 times as massive. Earth became a minor planet, "third rock from the Sun".
• Then the Sun was found to be a small-to-middling size star among billions of stars in the Galaxy, which was thought to be all the Universe. Solar system dethroned.
  
• Kant proposed that the Galaxy (AKA Milky Way) might be one of many. This was soon confirmed.
• In the 1920s Hubble showed that there are more galaxies than stars in the Milky Way. Galaxy dethroned.
  

Milky Way is a large galaxy, but hardly the largest. Solar system is about halfway out to its edge, in a (fortunately) poorly-populated area. We're middling critters on a middling planet of a middling stellar system in a middling galaxy. But we were still the crown of creation, were we not? At least on Earth??

• Freud, Jung and others showed how faulty our "normal" thought processes are. It remains true that most people would rather die than think, and as B. Russel quipped, most do.
• Darwin showed that humans are specialized apes, part of the animal kingdom, not a kingdom to ourselves. The Bible had warned us not to be proud; now we could see a few reasons why.
  

But we still rule the Earth, don't we? This is the premise behind those who panic over our supposed power to "destroy the biosphere". There was an earlier panic about this, called the Cold War. The US and USSR each had about 20,000 megatons of thermonuclear weapons pointed at one another. That is a lot, I'll grant. But consider:

• Mt. St. Helens, in 1980, blasted a half cubic kilometer of ash and pulverized rock into the sky, in the largest American eruption in historic times. It had the energy of 400 megatons. The largest thermonuclear device ever tested was about 50 megatons.
• Mt. Pinatubo, in 1991, blasted ten times that amount and had at least ten times the energy of St. Helens, about 1/10 the world nuclear arsenal.
  

Both volcanoes had strong local effects, such as lots of ash to clean up. There was modest cooling for a few months and some pretty sunsets. The much earlier eruptions of Krakatoa (10,000 MTons) and Toba (a million MTons?) did not terminate civilization, but did cause somewhat difficult winters, one each. If all nuclear weapons were blown off at once, it would equal about two Krakatoas, or a tenth of a Toba. Nuclear winter? Not more than one extra-chilly year.

Our influence is not totally insignificant. It seems we have, to date, added enough CO2 to the atmosphere to add a half a degree C (about a degree F) to global temperature. Just a thousand years ago, the European climate, at least, was 3°C warmer than today. In Dinosaur times, periods of millions of years were as much as 10°C warmer. The biosphere could handle that. Even earlier, a global ice age saw glaciers at sea level at the equator. The biosphere handled that.

I expect one outcome of the climate debate will be a further dethronement of humanity. We're able to rattle the bars of our cage and get noticed, after careful measurement. As for "ending it all"? Hardly.