Daily Science Dose

Bifurcation
Bi`fur*ca”tion\, n. [Cf. F. bifurcation.] A forking, or division into two branches.

Bifurcation is also the term that scientists have used to describe abrupt changes that can and do occur the Earth’s climate, specifically when the Earth shifts from an interglacial period as we are in now, to a more glaciated global climate.

Then…

…and now.

Here’s the deal. The Earth shifts in its orbit and in its revolution from time to time. It is nothing that happens over night, or even over a couple hundred of years. But it does happen. And it will happen. What does that mean for humans? It could lead to our adaptation to a new climate, or it could lead to our extinction.

Two researchers built a high-powered computer model to take a closer look at these intriguing phases of cooling and warmth.

In addition to the planetary shifts, they also factored in levels of carbon dioxide (CO2), found in tiny bubbles in ice cores, that provide an indicator of temperature spanning hundreds of thousands of years.

They found dramatic swings in climate, including changes when Earth flipped from one state to the other in a relatively short time, said one of the authors, geoscientist Thomas Crowley of the University of Edinburgh, Scotland.

These shifts, called “bifurcations,” appear to happen in abrupt series, which is counter-intuitive to the idea that the planet cools or warms gradually.

“You had a big change about a million years ago, then a second change around 650,000 years ago, when you had bigger glaciations, then 450,000 years ago, when you started to get more repeated glaciations,” Thomas told AFP.

“What’s also interesting is that the inter-glaciations also became warmer.”

According to the model, published in the British journal Nature by Crowley and physicist William Hyde of Toronto University, Canada, the next “bifurcation” would normally be due between 10,000 and 100,000 years from now.

The chill would induce a long, stable period of glaciation in the mid-latitudes, smothering Europe, Asia and North America to about 45-50 degrees latitude with a thick sheet of ice.

However, there is now so much CO2 in the air, as a result of fossil-fuel burning and deforestation, that this adds a heat-trapping greenhouse effect that will offset the cooling impacts of orbital shift, said Crowley.–Agence France-Presse

The article goes on to add that…

Crowley cautioned those who would seize on the new study to say “‘carbon dioxide is now good, it prevents us from walking the plank into this deep glaciation’.”

“We don’t want to give people that impression,” he said. “(…) You can’t use this argument to justify [man-made] global warming.”

So, let’s review what this new finding means to us today. Scientists are a funny bunch, and they are always playing the “what if” game, and in this game, we find that the natural cycle of the Earth’s orbit will again cool the planet in 10,000 to 100,000 years from now. That’s a pretty big window, but let’s say that a new ice age would be hard on us as a species. However, as some people like Senator James Inhofe and even Governor Sarah Palin may claim as a result of this new finding, the amount of carbon dioxide, methane and other greenhouse gases we have pumped into the atmosphere for a century and a half and continue to pump in larger and larger amounts will somehow avert the new glaciation in 10,000 years.

Too bad global warming is going to hit us first, in the next 100 years or sooner. I will take my chances against a colder world. There will still be warmer regions, just not that many of them. Not much you can do when it gets too hot. That situation along with the other problems that carbon dioxide pollution causes will render the planet much less inhabitable than Canada freezing over.

Maybe there is a way for scientists to jiggle the Earth in its orbit, tweak its axis angle, and find the perfect distance from the Sun in order to speed up this coming Ice Age. If we could only find the perfect balance between greenhouse emissions and the Earth’s distance from the Sun, then we could keep on pumping and drilling and burning…until the carbon-based fuels run out.

No offense to the new study’s authors, but duh. We all realize that the Earth will naturally move back into a glacial period, and we don’t need to waste time debating whether or not the carbon in the air now will somehow stop the Earth from freezing over — ten thousand years from now. We are screwed waaaay before then.

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