Climate Change

[mac]

By a friend who does tours in San Francisco. If we had started doing this when Carter was POTUS…

[GURGLETROUSERS]

In thinking over the undeniable global warming pattern something, to my mind, doesn't add up. The retreating ice caps and glaciers of the present day are attributed solely to 'our' swamping of the atmosphere with CO2. NO natural forces are claimed to be involved. To my geological mind I ask how can that be?

Geologically the earth's average temperature is accepted (or always was in my time) to have been higher during the majority of the geological periods than that of recent (i.e. last million years) time. Since the end of the 'recent' (geologically speaking) ice age the natural average temperature should have been steadily rising ( Bouncing back.) It apparently is not said to be doing so.

So today, if we remove the man made CO2 factor, the earth appears to still be on hold, which begs the question, are we merely in another extended interglacial period because the ice age really has not yet ended?

With my geological hat on, I could be forgiven for thinking so!

[GURGLETROUSERS]

P.S. Sorry for rushed typing. Wanted to add a lot more, but computer issues.

[swchandler]

G.T., while I'm far from being knowledgable about the science and theory behind climate change and global warming, I think that under current circumstances we can't remove increasing CO2 from the mix. It is my understanding that the very rapid change in CO2 amounts (parts per billion in our atmosphere) over the last 200 years or so is driving our global warming condition. The big question is whether all life today can evolve quickly enough to survive and preserve the world that we know.

You're right though about us being in a period where we are warming from the last ice age. When you think about it, the assent of humans and our development over the last million years or so is greatly dependent on the conditions inherent to the ice age recovery time period. Who knows whether we, as a species, would have thrived in a much warmer world that preceded us.

[mac]

GT--without greenhouse gases, this planet would not be habitable. Certainly there are geologic processes that go on that affect temperature, in a small way, and more greenhouse gases than just CO2. But there is no doubt that the dramatic increase in CO2 and methane because of mining and burning fossil fuels accounts for most of the warming. Further, stopping generation of CO2 will not stop the warming. According to my contacts at Scripps, there is enough heat already stored in the ocean to assure us of a century, and perhaps two, of global warming. We can measure the heat, with some precision, but we don't know how rapidly it will be released from the ocean and affect the terrestrial climate.

[GURGLETROUSERS]

I'm not disputing that the current warming is driven by our non natural swamping of the earth's atmospheric CO2 level, and next to no natural component, but that is the issue in what I was trying to say. i.e. WHY is the natural component missing?

If 'our' interfering CO2 cause wasn't there, the earth's natural insistence on returning to its default higher average temperature should have 'kicked in' by now, after the recession of the recent Ice Age. By all reckonings it doesn't seem to have done so. (Over and on top of our CO2 driven factor.)

In the 1950's it was a hotly debated subject of whether the Ice age had truly ended? What was accepted then was that natural forces were by no means SMALL, or of limited effect. The Ice Age itself was truly astonishing in its effect! It was also realised that certain periods in the geological record were equally powerful in their effects. The Carboniferous period, at its opening, was truly amazing, in that natural CO2 atmospheric levels must have been at least 8 times as high as any seen today. In such a hot house earth wide covering that could have been no ice caps, no glaciers, and probably no ice at all. (Hardly just small natural effect.)

So what if we truly are just in an interglacial period before that next ice covering? That would be catastrophic for the human race, over say the next hundred thousand years and onwards. What proof is there that it isn't so?

[GURGLETROUSERS]

I fished out from the attic one of my old geology student 1950's study into the Ice Age effects on the drainage patterns of our local moors.

It's amazing how once important to us topics simply fade away with the passing years. What was once an intense interest, is now just a bloody nuisance when I fall down some Ice age induced hole in the ground, riding the mountain bike. It certainly helps us humans realise how history is able to repeat, when we forget the past.

[swchandler]

To be honest, I think that the last thing that we need to worry about right now is the coming of the next ice age. I worry far more about the direction of change that is quickly unfolding right before our eyes.

What happens when something on a massive ecological scale deals a death blow to much of the insect world? Let's imagine that insects are no longer there to pollenate plants. The potential for far reaching results can happen in no time at all. The interrelationships in our world are infinitely more complex than we can imagine, and just a few important changes to our environment can spell disaster on an unbelievable scale. Pretty sobering when you think about it.

[mac]

GT—This article from 2019 in Science contains the graph I’ve copied here. While there are blips, like the little ice age (which had really dramatic effects in places like Glacier Bay in Alaska), those blips are tiny in scale compared to the long term trends. The trend has been down for 50 million years, and the last ice age blip was about 20,000 years ago. The natural trend was down—overwhelmed by humans burning carbon. https://www.science.org/content/article/500-million-year-survey-earths-climate-reveals-dire-warning-humanity

[GURGLETROUSERS]

Steve. Insect life evolved long long ago (480 million years ago) and were rampant from the then Ordovician period onwards to the present. It strikes me nothing but total earth destruction will get rid of the little blighters!

Flowering plants and pollinating insects such as bees evolved by the Cretacious period (over 100 million years ago) and have been with us ever since. I think both have proved they are survivors.

That MAY be more than can be said for us. It is clear that our human ancestors evolved somewhat rapidly during the last 1 million plus years, during which time the earth's average temperature has been depressed, or very depressed (Ice Age and aftermath). Hence our bodies and brains are adapted to live with that. Perhaps it's we, not the insects (the blighters) or flowers (Ahh) which may meet our Waterloo in the future extreme heat waves?