Posted on 04/18/2006 8:47:13 AM PDT by beebuster2000
ICE HOUSE or HOT HOUSE?
During the last 2 billion years the Earth's climate has alternated between a frigid "Ice House", like today's world, and a steaming "Hot House", like the world of the dinosaurs.
This chart shows how global climate has changed through time
(Excerpt) Read more at scotese.com ...
"Big picture. So what if oceans rise 3 meters?"
I'd gladly give up my home at 16 feet MSL if we could get the sea level to rise enough to flood the Middle East.
LOL. But then they would want to come here. Don't want 'em.
Thank you.
I don't disagree with anything you have said. The problem is the "mights" and "mays." There is not nearly enough data to support the humans cause global warming position at this point. It could be true. It could be false. We have no way of knowing. It is a conjecture, at best. Give me any conjecture and I can build a model that 'proves' it on a computer screen, so long as I do not have to validate the model against reality.
So the real question is: Do we shut down our economy and turn power over to the little Eco-Stalins because of maybes. The question answers itself to any reasonable person. But if one is an Eco-Stalinist, the answer seems to be equally clear.
Amen. And well said.
My original post was a bit extreme (I often find it's good to begin that way and then whittle it down).
You're correct that scientific models need to be verified against past data. You say that "The most important single step in modeling is validating your model against known data", and I agree, but the point is we don't have reliable "known" data from 200 mya. The further we go back in time, the more uncertain we are. Climate models in their validation often go back no further than 100 years (although some do go back 1000 years).
There's a fallacy that I was trying to point out.
1) The climate has changed in the past for natural reasons
2) The climate is currently changing
3) Therefore the current climate change must be natural
That reasoning is fallacious. The point I was trying to make is that yes, scientists have to understand how the climate works and it helps to look at the climate over the past 200 million years, but they have to investigate what is causing the current climate change (which is deemed anomolous)
The present warming trend began before the start of the industrial revolution.
The warming preceded the recent increases in atmospheric CO2.
The oceans are a great reservoir of CO2. When they warm up, they cannot hold as much CO2 (outgassing).
The warming that has increased CO2 levels, not the other way around.
I'm not sure that stacks up too well on the evidence. What "warming" are you talking about? Typically, climatologists divide it up into the periods ~1880-1940, which is deemed to be due to natural factors, and from 1960 to the present, which is deemed to be largely due to anthropogenic greenhouse gases
I'm not sure that stacks up too well on the evidence. What "warming" are you talking about? Typically, climatologists divide it up into the periods ~1880-1940, which is deemed to be due to natural factors, and from 1960 to the present, which is deemed to be largely due to anthropogenic greenhouse gases
Exactly. I am all for further study, and "keeping an eye on things", and if it ever gets to the point where we know we have to do something, then lets do it. However, I think we are still quite far from that point.
Not quite accurate, WW. The climate system has a lag time of response, mainly due to the heat content of ocean water. Over millions of years in paleoclimate history, the rate of change doesn't mean much. But over centuries, it is an important variable.
Here's some help on that:
Point one: the reason that now is different from any previous "then" is that a signficant increase in atmospheric CO2 is occurring during a very stable interglacial period, on a timescale for which no other natural Earth cycles will have a significant, noticeable effect. The only possible effects on this timescale are from major volcanic eruptions and changes in solar activity. As for the latter, data does not indicate a significant solar influence, though some warming in the early 20th century is attributed to an increase in solar activity.
Point two: about 55 million years ago, the Paleocene-Eocene Thermal Maximum occurred. Based on carbon isotope data, it is believed to have been caused by a major methane release over several millenia, and the methane oxidized to CO2, making the effects last longer. Though imperfect, this is the best analogy to the current situation, whereby a gas influencing Earth's radiative balance increased markedly (with no other cyclical contributions), with resultant increase in Earth's global temperature.
Even though the Earth is currently warming, the oceans are a net sink for CO2.
Bullshit.
"Stocker and Schmittner's study concludes that the severity of a disruption in thermohaline circulation brought on by global warming will depend on the rate of warming and, hence, on the rate of greenhouse gas emissions. With a well-tested, coupled atmosphere-ocean climate model they show that, at present-day rates of carbon dioxide emission, thermohaline circulation will cease altogether by the time that atmospheric carbon dioxide concentration has doubled (to 750 p.p.m.v.). However, if carbon dioxide concentration increases more slowly, circulation will merely weaken with a doubling of atmospheric carbon dioxide concentration. The limits of climate models prevent exact predictions as it is impossible to include in the model all possible parameters and feedbacks. A particular source of uncertainty is change in precipitation, which is the deciding factor in thermohaline circulation shut-down."
*
Iceland has always sucked.
OK, if we assume that human activity is now causing global warming, how do we know that in trying to reduce those activities we don't go too far and then cause global cooling?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.