Question about climate change: Why do most predictions call for a big desert

when back in the day the dinosaurs roamed around a huge swamp? :shrug:

Why would climate change not produce a big swamp?

Thanks. :hi:

sometimes you don't.

the result of catastrophic climate change means that earth will then be "like when there were dinosaurs".

Lots of water (no polar ice caps) and lots of heat.

"back in the day when the dinosaurs roamed around"?????

:crazy: With that kind of logic, It's like Limbaugh is posting on DU now.

:eyes: yourself.

Climate change is about more than "heat".
Remember that our atmosphere is also dissipating, and the "water" won't all be around.

Sometimes the basics don't give you the right answer.

So, basically, you're saying that the Earth will be barren like the Moon?

Could you cite some studies that suggest this is true?

I'm building a solar boat and without water, well, what's the point?

I have the boat, the panels, the batteries, and a brand new 150 pound thrust motor.

We let anyone post! Even ill-mannered people like you. I mean really, someone politely asks a question, and you flame them.

Try the following Google search:
http://www.google.com/search?q=Chris+Thomas+warming+dinosaurs

All those melted ice caps... all that extra water... all that heat... spells swampy jungle to me.

Here's the IPCC prediction (from the 2007 report) on changes in precipitation by the end of the century.

Note that in some places there will be more precipitation, and in some places there will be less.

For example, the SW US (where you are) will be dry, and the NE (where I am) will be swamp.


Of course, we've learned a fair deal since then.

So you're telling me the water will all pool up sub-surface!?

(Sorry, should have given a spoiler alert for that one.)

Or bring the Dead Sea back to life?

I just don't get it.

salt flows, wind patterns and most importantly albedo.

The desertification of North Africa, which was once known as the "granary of the Roman Empire" - although the term http://books.google.com/books?id=Hwu3S5i-2QQC&dq=granary+%22north+africa%22&printsec=frontcover&source=bl&ots=HnqxPgrvgY&sig=8GN3TuVfTqhVWNvOHxLttYaOPJs&hl=en&ei=7r61ScaBOpHCMdyemdUK&sa=X&oi=book_result&resnum=1&ct=result#PPA5,M1">is claimed to have ridden a bit on French Colonial hyperbole was almost certainly related to Roman (and Carthaginian) irrigation practices.

The myth of the Romans sowing the Carthaginian fields with salt to destroy Carthaginian power forever is probably a political tale told to place an onus on the conquerers for a process that was inevitable in any case.

Once the soil became saline, its capacity for holding water at all was reduced by the lack of roots that could take hold in it. The lack of ground cover - with shade - also effected the capacity of soil to hold water, and in turn, in a feed back loop, increased salinity.

Salt flows are the hidden cost of damming rivers and distributing their water on fields. Besides damning the rivers by damming them, the soils around them are also destroyed. Just look at the Salton Sea.

Another factor is the higher capacity for water in hotter air. Air is saturated and produces precipitation much more easily when it is cool than when it is hot. A "cold front" where the cold is 30C and the "warm" is 40C is simply not going to yield as much rain as one at 10C/25C. It's just physics.

More water is retained in hotter air, and ironically water is itself a greenhouse gas.

An unstated long term consequence of high humidity in an atmosphere is sometimes believed to have played a role in the evolution of the Venusian atmosphere. UV radiation splits water and hydrogen on all terrestrial planets has a significant population of molecules (by Boltzmann type statistics) that exceed the escape velocity of planets roughly at Earth/Venus masses. (This is why for instance that helium - the second most common element in the universe - is rare in both planetary atmospheres, even though both planets continuously produce the element through the radioactive decay of uranium and thorium in their crusts.) The oxygen produced on Venus in this process probably reacted with reduced carbon which acted - in the absence of life - as an oxygen sink. Carbon dioxide is one of the main constituents of the Venusian atmosphere. This same process may have played a role on Mars. Earth's escape from this fate seems to have been a happy function of its distance from the sun, it's mass, and its initial composition, which in term allowed for the evolution of life, which ultimately allowed for the evolution of life, with the ultimate oxygen evolution preventing or slowing the photolytic dissociation of water. Mars was not massive enough to avoid this fate, and Venus was a little too close to the sun for comfort.

I had a book that I loaned to someone - never loan books - that was an excellent discussion of these topics, http://www.allbookstores.com/book/9780198503750/Richard_P_Wayne/Chemistry_Of_Atmospheres.html">Chemistry of Atmospheres : An Introduction to the Chemistry of the Atmospheres of Earth, the Planets, and Their Satellites

That was, by the way, an excellent question.

:hi:

:think:

...in sagebrush country about 20 yrs ago...when a couple of biologists (?) came around surveying the mine for eventual reopening...so asked them just what the global warming thing was really all about...and they said that it would result in more extreme variations in weather.

This was 20 YEARS AGO.

The US West is apparently going the way of S. Australia...