Science News Review

Global Cooling, Global Warming

Aug 8 at 2:02pm by Aileen

Researchers from Oregon State University and other institutions have published an article in the journal Science that they say puts to rest a long scientific debate on the causes of periodic ice ages in the history of our planet. The conclusion? Earth Wobbles.

The last major ice age reached its peak about 26,000 years ago, held steady for about 7,000 years, then began melting 19,000 years ago. The melting was caused by an increase in solar radiation, the researchers say, and not by carbon dioxide’s “greenhouse” effect, or any changes in ocean temperatures. These mechanisms have been cited recently by some scientists trying to understand what appears to be happening now with the increase in global temperatures termed “Global Warming” and said to be caused primarily by pollution from human activities.

The researchers analyzed 6,000 dates and locations of ice sheets to define when they started to melt. This confirmed a theory developed more than fifty years ago that held small but definable changes in Earth’s rotation as the trigger for both the accumulation of ice and its melting cycle. Putting that together with changes in the Earth’s axis and rotation going back 50 million years, they found that the gravitational influences of the larger planets – primarily Saturn and Jupiter – leads to predictable cycles.

Right about now, the scientists say, we should be changing from an interglacial period toward conditions that will ultimately lead to another ice age. That is, if human contributions to Global Warming don’t thwart the process. Meanwhile, a close look at plans to mitigate global warming with ‘Geoengineering’ suggests that such plans may well do more harm than good.

Research presented at a symposium at the Ecological Society of America’s annual meeting concludes that geoengineering is potentially dangerous, and that the risks outweigh the benefits. Plans such as limited nuclear detonations and subsequent fires to release lots of carbon into the atmosphere, seeding the atmosphere with light colored sulfur particles to mimic gigantic volcanic eruptions, and seeding the oceans with iron to increase carbon uptake all come with side-effects that could be disastrous, ecologists say.

Indeed, if we are starting to ‘wobble’ to the gravitational tune of our giant planetary neighbors toward another ice age, taking big efforts to cool the planet right now could actually speed up the process! Perhaps we should put off the big projects until we know more about all this, eh?

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