Global cooling: Wind up the wurlitzer and let her rip!

There’s no doubt the earth has undergone periods of relatively abrupt warming and cooling in the distant past. We know it defines the onset of the Pleistocene for example, marking the beginning of classic ice ages. I doubt you can find a biologist who thinks either one could happen without affecting ecosystems far and wide. But how long before the usual suspects strip out the paleo-climate and atmospheric context of this and enlist it to confuse the laypublic on climate change?

NNWN — Many studies have focused on the effects of global warming, Now, researchers have shown that a phenomenon called “global cooling” that occurred about 116 million years ago was associated with the loss of marine life.

Global temperatures began to drop primarily after the super-continent, Pangaea began to drift apart, hence creating large oceanic basins. In the study, researchers showed how the rise of water bodies around continents reduced temperatures around the world by increasing the surface area for marine algae to grow. The dead algae were buried in the sediments and locked up a certain amount of carbon with them that reduced the atmospheric carbon dioxide.

Low levels of the gas in the atmosphere led to a major shift in the carbon cycle with global temparatures dropping to 5 Celcius, about 2.5 million years ago. This “cold snap” ended when intense volcanic activity in the Indian Ocean began adding high volumes of carbon back to the atmosphere. The warming began about 2 million years back.

It is worth noting that the global cooling effect occurred over a period of a million years while human-induced global warming has occurred just over a few decades.

It would be easy to use that to sow confusion. Ask someone with little knowledge of the basic sciences involved and they could easily come away from that article thinking this study found the average global temperature 2.5 million years ago was 5° C, (41° F). Brrrr! That’s quite a chilly indeed!

It’s also dead wrong. The average global temperature today is about 14°C (57° F) plus or minus one or two degrees depending on how its calculated. There is little doubt among experts that global averages in the Cretaceous and Jurassic were considerably higher than today.

It’s so confusing I’m not even sure if I’ve unraveled it correctly. But presumably, what the staff writer above was trying to convey is the study’s author’s theorizing that less photosynthetic biomass led to a drop in CO2 resulting in a decline of about 5° C, and that this took place over 2.5 million years beginning about 116 million years ago.

Fossil fuel fronts won’t be nearly so circumspect. Quite the contrary, they are eager to capitalize on exactly those kinds of mistakes.


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