January 8, 2007

Washington DC: 80 Degrees on January 6

Yes, it's anecdotal, technically, but it sure is strange. My aunt was telling me that the Severn River used to freeze completely over, to the point where she could literally walk miles to different areas. Our waters haven't frozen to that extent in decades now.

The Arbor Day Foundation just released an updated "hardiness map" depicting the creep of warmer climes north. Jen has written a more detailed post about the release worth checking out.

This is the second map of changing temperature averages I've seen in the past couple of days, the first was shown on the evening news on Saturday.

Two other stories caught my eye today, one from the LA Times:

Foreshadowing potential climate chaos to come, global warming on a young Earth caused unexpectedly severe and erratic temperature swings as rising levels of greenhouse gases helped transform the world, a team led by researchers at the University of California at Davis said Thursday.

The transition from a global ice age to global greenhouse 300 million years ago was marked by repeated dips and rises in the amount of carbon dioxide in the atmosphere and wild swings in temperature, with drastic effects on forests and vegetation, the researchers reported in the journal Science.

___snip___

Instead of a relatively gradual transition from a cold world to a warm one, as many scientists had believed, Montanez and her colleagues found fever spikes of climate change correlated with fluctuating levels of carbon dioxide, like a seismometer graph of the myriad tremors before and after a major earthquake.

"(Carbon dioxide) goes up and temperature goes up. It drops and temperature drops," Montanez said.

"It suggests," she said, "that the normal behavior in major climate transitions is instability, erratic temperature behavior and carbon dioxide changes."

Take home message: We are observing the same phenomena right now, an instable and irregular climate that is highly unpredictable from week to week. In the past it was due to natural cycling. This time around, it is our fault.

The other story reports recent research that suggests that regional climate change has been the cause of the collapse of empires in the past:

NEW research suggests climate change led to the collapse of the most splendid imperial dynasty in China's history and to the extinction of the Mayan civilisation in Central America more than 1000 years ago.

There has never been a satisfactory explanation for the fall of the Tang emperors, whose era is viewed as a high point of Chinese civilisation, while the disappearance of the Maya world perplexes scholars.

Now a team of scientists has found evidence a shift in monsoons led to drought and famine in the final century of Tang power.

___snip___

The scientists discovered that titanium sediment and deposits of magnetic minerals in a lake in southeast China indicated that the period was one of intense climate change that left northern China a desolate waste.

___snip___

According to the scientists, the 8th and 9th centuries saw a worldwide drought in many regions. They conclude that it ruined entire societies.

Chinese chroniclers recorded the decay that set in during the late Tang dynasty, which ended in 907. These correlate with the new scientific evidence.


These civilizations were nowhere near as technologically advanced as we are today, but this time around, the climate change might be global, and I can't think of any contemporary technology that might save us from the effects. People are even more tightly packed by the millions, in highly sensitive regions.

Even with this strange weather, I don't think the sky is falling just yet. These kind of warnings are best heeded, however.

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