Almost to post number 500! (doesn't seem possible, but it's true) - and it just so happens to be one of those "bees in my bonnet" topics - global warming/climate change.
via National Geographic again, an ice core recovered from the South Pole by a French research team shows the climate history for over 3/4 of a million years. Earth has been up to 10 degrees colder and almost 5 degrees Celsius warmer over the historical record. The interesting thing is both the warmest and coldest periods that were uncovered were relatively recent, dating back to the latest Ice Age.
"The new climate record covers an additional cycle of glacial change, amounting to 11 cycles in total, lead author Jouzel said. Plugging the data from the entire core into an atmospheric model, the scientists were able to reconstruct a reliable temperature record for the past 800,000 years. In today's online journal Science, the team showed that the coldest period occurred around 20,000 years ago, during the last glacial maximum, when the ice sheets were at their peak.
It was about 10 degrees Celsius (18 degrees Fahrenheit) colder than today. (Related: "Antarctica's Atmosphere Warming Dramatically, Study Finds" [March 30, 2006].)
Meanwhile, the warmest period was during the last interglacial period, which is an interval of warmer global average temperature that separates ice ages. At that time, around 130,000 years ago, it was a balmy 4.5 degrees Celsius (8.1 degrees Fahrenheit) warmer than today."
This is another of those things the global warming crowd don't seem to understand, or willfully choose to ignore in order to try to make their political point, which seems to be that we should all go back to horses and buggies or something.
We are still recovering from the last Ice Age, and there have also been quite a number of climate oscillations (like both the Medieval Warming period and the Little Ice Age within the last millennium, for example) within that time frame. So a 1 degree warming trend over the course of the last century (which is the biggest piece of evidence used to justify the warming theory) just isn't that big of a deal, and furthermore, no one can prove just how much human industrialization has influenced the warming we've seen.
Humans have adapted to far greater climate changes over just the last 20,000 years without the benefits of our current technology, so it is difficult to imagine (for this writer at least) a scenario with changes so severe, so dire that we can't adjust to it, however painful any change might be. Call me an optimist, but I believe humanity will survive, whatever actually occurs. So completely altering our economic and industrial base to address a potential, but still unproven (and unlikely) disaster just doesn't seem like a wise policy course for us to undertake.
Perhaps better evidence will be forthcoming and we will all die in a global cataclysm of flooding, the roaches will eventually take over and discuss amongst themselves human civilization the way we do the dinosaurs - but I doubt it.