Australian Heat: It's the Sun, Stupid

by Laurence Hecht
February 8, 2009

Editor-in-chief, 21st Century Science & Technology

Carbon dioxide-induced global warming? No, it's the Sun, stupid. The same Earth-Sun orbital relationship which threatens to put the northern Hemisphere into a new Ice Age is contributing to summer-heating in the southern hemisphere.

It's summer right now in Australia, and the Earth now finds itself closer to the Sun during Southern Hemisphere summer than at any time in the 21,000-year combined cycle of precession and advance of the perihelion which drives long-term climate. Combined with local climatic effects, it should not be surprising that high temperatures and wild fires, hardly a new experience, are occurring there. Conversely, our Northern Hemisphere summers are occurring at the point in the long precession cycle known as aphelion, where the Earth is most distant from the Sun.

Global warming? It never happened. The entire 0.6 degree C rise in global averaged temperature that was claimed for the 20th Century was eliminated by the last 10 years of global averaged decline. Global averaged temperature is a meaningless concept, in any case. A man standing with one foot in a bucket of boiling water and the other in a bucket of ice water, would have a comfortable average temperature.

The important determinant in global climate is the cycle of glaciation. Like all real physical processes, the Earth's climate is asymmetrical. The convergence of the Earth's land mass towards the north, has meant that periodic glaciations have covered the northern continental landmass over approximately the past 2.5 million years. The last one, which brought mile-high glaciers as far south as New York and Chicago, just ended about 11,000 years ago. By the best estimates of previous patterns, glaciations of 100,000 years or longer have followed the brief periods of 10,000-12,000 years, known as interglacials, like the one we have been experiencing for the recent 11,000 years. The next one could be on the way anytime soon. Cooler northern hemisphere summers mean that the ice and snow build up of the previous season may not melt back. As this goes on over a number of years, the ice pack begins advancing, and begins to build up a momentum of its own. The increased reflectivity of the growing ice-covered surface area contributes to local cooling, allowing more advance.

If human-induced global warming could warm the planet a bit, it might be a good thing. But we can't count on it, as carbon dioxide also contributes to plant growth (a good thing for those who like to eat), and to cloud cover, which may cool the Earth as much or more than the slight greenhouse effect. What we should more reasonably be worrying about is the start of a new glacial cycle. Should such an event get underway, what we will want at our disposal is a scientific capability that includes the highest energy flux density capability—nuclear and fusion power, not windmills and solar panels.

For further reading:

http://www.21stcenturysciencetech.com/Articles%202008/warning_ice_age.pd...