Climate debate heats up; no signs of it cooling down

The recent media is littered with articles advocating or denying the global warming theory and its catastrophic projections for human civilization.  ‘It’s the end of the world as we know it’, claim the advocates; ‘it’s political propaganda trying to institute a global socialist agenda’, claim the deniers.  A recent report from MIT recently raised the stakes on the global warming projection wheel stating that the probability of a warming trend in the 21st century is likely without stringent reductions in greenhouse gases, sparking a new round of opinionated commentators.

Which is it; is the earth warming as believers and some scientists say, or is it cooling, as the deniers and other scientists say?  The historical record indicates that one leads invariably into the other (although the timeframe depends upon the span of geological epochs that it covers).

The problem in the modern era, though, is not centered on the  fact that the earth is warming or cooling, nor is it based primarily upon whether CO2 rises precede temperature gains, which seem to be two of the three main arguments of skeptics.  Rather, the problem is that atmospheric concentrations of CO2 have been altered significantly from the recent historical trend, and we don’t know yet what the ramifications of that will be.  The final argument of the debate concerning global warming right now is over whether or not humans caused this spike in CO2; skeptics claim it is just a part of the natural cycle of things.  The dissenters may have a point here. In the earth's very distance past, Precambrian through Ordovician, higher concentrations of CO2 (2000 ppm or more) resulted in similar temperatures to the ones we enjoy today; but according to Royer, "the geologic record contains a treasure trove of 'alternative Earths'"where the relationship between CO2 and temperature was significantly different than it is today and has been in the more recent past (see the second graph in this post).

CO2 is the bedrock of the earth’s climate; the global climate has alternated between warming and cooling periods throughout its vast history.  Specifically, over the course of the last 400,000 years, rises in atmospheric concentrations of greenhouse gases (CO2 primarily) have coincided with rises in temperatures (albeit, "the lag over the last 40,000 years is around 800 years").  According to data pulled from ice core samples at the Vostok Station in Antarctica, atmospheric CO2 levels for the past 400,000 years have never risen above 300 ppm; when they approached 300 ppm, temperatures plunged, and the earth slipped into an ice age.  Today, they are at 390 ppm.  If we follow the pattern of the recent past, we are in for dramatic changes on earth in the coming centuries; if the planet's climate has fundamentally changed to be more like that of the very distant past, then we have nothing to worry about for some time.  Once again, the earth has room for skeptics and believers alike.

 

We are talking about geologic time here, so to say that global warming is a hoax because it snowed recently is ridiculous.  We are talking about vast spans of time, and the farther back we go into it, the more speculative our assumptions become; yet, certain trends materializing in our modern, industrialized world are troubling.  CO2 levels are rising relatively dramatically.

While data that stretches farther back into history (some 600 million years) shows...

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http://www.examiner.com/x-2903-Energy-Examiner
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