Re: Global Cooling will kill us all!
Posted: Wed Jan 02, 2013 1:04 am
One of the biggies? The ice cores at the Byrd Polar Research Center. Which I have actually helped carry in a panic when their freezers died one day.LowKey wrote:Somewhat of a follow up to the previous question (also not a sarcastic dig)-
In the past it had been belived that the onset of glacation was gradual, and this theory persisted for decades until further research and discoveries displaced it with the present theory thprocessestion is much more rapid, occurring over a few decades.
What evidence do we have that supports that a natural post glaciation return to the "normal" hotter baseline temperature is a gradual change rather than a rapid one? There have been mass extinction events in the past....could they not in some cases been caused by rapid warming of the climate? One I am thinking of is the sie off of mega fauna at the end of a previous period of glaciation....
To rebut your main point: Rapid climate change is absolutely not "proven to be the norm. Neither is it entirely unprecedented, it is just very rare.
Anyway, yes, there are periods of rapid climate change in the geological record, though not quite as rapid as the impression that you've been given. However, the OVERWHELMING number of climate change cycles have been EXTREMELY slow by human terms, on the order of hundreds of thousands of years. Here's the kicker: every single one of the fast ones was accompanied by a mass extinction event to a greater or lesser degree. When rate of climate change exceeds the ability of the species to evolve in lockstep, we tend to lose a significant fraction of the total species of life on earth. So, while there are a few examples of climate change in the past approaching the rate at which it's happening now (though usually in the other direction, strangely), it still means we're going to get our asses kicked.
Also, you really need to be careful when you hear a geologist or a climate scientist use words like "rapid" or phrases like "relatively brief". They don't always use words the same way you do. I've actually had a geologist use the phrase "a relatively brief 200,000 year period" to describe a particular glaciation event in casual conversation. Another paper I'm reading right now is referring to "rapid cold and hot phases resulting in significant changes to glaciation". Those "rapid phases" are 1,500 years long.
Finally, as far as "stop wasting our time blaming ourselves" the problem is that no one except the talking heads on TV are doing that. We know beyond doubt that many of the byproducts of the industrial age (CO2, methane, etc) are forces in the overall climate that increase heating. It really doesn't matter if the current upswing in temperatures is solely the result of that or if it's just bad luck that we did bad things at the same time we hit a bad phase of the cycle. What matters is that, for whatever reason, the system is heading in a direction that's very bad for us and we are doing things we know make it worse. Step one to surviving is to stop making it worse by reducing the amount that we're doing to force the system hotter.Not that the answer would change the conditions humanity to which humanity would need to rapidly adapt, but if rapid climate change in both warming and cooling are proven to be the norm then perhaps people would stop wasting time blaming themselves and others for a natural process that can't be stopped and direct their energies and resources to adapting to the change.