The following is being posted so that I do *not* have to continually regenerate it... I have been saying this for months, now, and really do need to have one, pithy post to refer to and this will be it! Naturally it is a *comment*, in this case at Roger L. Simon's place on a thread on global warming.
Spelling and such are kept intact to show the inabilities of the author:
jdwill - My thanks! Those are the merely cyclic things that will happen in North America that I consider to be the top 5 problems that we haven't even started to address... and one #1 has global fallout both figuratively and literally.Yes, I am getting tired of restating the basics. If you can't figure out plate tectonics, volcanism, mountain building, oceanic heat retention, placing a heat sink in the southern polar region, and taking into account at least 800 million years of Earth's history... then do *not* bother me with carbon dioxide and methane amounts in the atmosphere until the oxygen percentage drops below that sustainable for terrestrial life, ok?
I did look at global warming previously, and as a geologist, find much higher correlation with plate tectonics and continental configuration than with carbon dioxide for global temperature. About 70 million years ago the continents started to move faster, due to unknown factors in the core of the planet and heat transmission. That had the effect of speeding up crustal movement, which allows the less dense continents to ride higher than the oceanic crustal material. That rise in the continents drained the large, shallow seas over much of them into their deeper basins, thus changing the stored energy system of Rock 3 from the star Sol.
This single change also started to move Antractica into a polar position, which is very rare in Earth's history and gave it a heat sink which drastically altered the heat retention system of the planet: It got a permenent cold place to let heat escape into space. Global temperatures started to fall due to these things.
Other effects are also seen, like increased volcanic activity due to subduction of oceanic plates. Apparently more 'hot spots' started to appear and give the planet more volcanos that way, including some of the megacaldera makers that started to show up around that era.
At Continental plate boundaries that were colliding, seas got squeezed out and when the continental crusts hit, they got squeezed together. The Himalayas are *still* growing upwards due to the Indian sub-continent pushing into Eurasia. The Rocky Mountains were also effected by this, as seen by the embedded river systems of the Green and Colorado rivers.
A final kicker was a nice sized boloid about 10km across hitting the planet. It was not a good time to be an organism over 15 kg in size as you would not make it through that event, at 65 million years ago. Since then, having lost those lovely, warm heat retaining, shallow seas, having the thermostat pushed down by the boloid and having a nice, new heat sink, Rock 3 has experienced glacial periods with intermittent warming times, that have high variability within a cool temperature range. That is typical of interglacial periods: rapid swings in temperature, globally, but within a confined range that is generally warmer than the glaciation period, but much, much colder than the previous Cretaceous period.
Can we get back to those balmy days of 70 million years ago with only changing carbon dioxide? And methane? And water vapor? Probably not... those all reached maximums in the Carboniferous when carbond dioxide was around 7,000 ppm and calcium carbonate rock deposited via chemistry and animal activity, like with foraminfera. You see a *lot* of coal beds and calcium carbonate beds from this timeframe, both indicative of taking carbon *out* of the atmosphere. Our current 300 ppm +/- 15% is a long way from those hazy, lazy days of high methane, carbon dioxide and water vapor... all of which saw a relatively stable global temperature 14 degrees higher than it is now. Actually, once the continents aren't moving fast and we have vast, shallow seas and low volcanic activity, that seems to be the regular temperature of the planet.
That higher energy from the core is released through these mechanisms, but it doesn't much impact climate which is guided by these factors which are a way of releasing heat. Such pretty volcanos, though! But not worth it for the hot gasses that cool extremely quickly, hot extruded material which cools quickly and the hot particulates that cool very quickly.
Want to raise the temps? Stop the plates from moving after re-uniting Gondwanaland and getting Antarctica out of the deep freeze. And then flooding most of the continental lowlands as they slowly settle down and behave themselves. Like NOLA, but with 1 km more water added. Then you get nice, shallow seas retaining energy from the sun and higher global temps. Of course the Rockies turn into 'coastal areas' but well worth it for stable temps and removing glacial periods.
As for us that live on the crust, the long term forecast is: sudden temperature swings, with a relatively narrow temperature band for some short duration and then sudden, long-lasting cold spells with 1.5 km high continental glaciers and the temperate zone shifting to the equator during those times. Check the 5 million year forecast to find out when this will end and the good old days return...