Global Warming question...not a debate.

[conestogo_flood]

Okay, today we learned about Global Warming in Physical Geography and something got me thinking.

There is a theory that the Plains of North America could become a desert like area in the coming decades, and I started to wonder...

All those droughts occuring in Texas/Oklahoma and wildfires, could this be the beginning? Scientists say that the process has already begun, so could this be the beginning. It was said to start in the south and move further north over time, so one day Texas, Oklahoma, Kansas, S & N Dakota, Saskatchewan and Manitoba will be that area.

Get what I am saying? People I talk too from the Texas Panhandle say the grass is turning to dust right now.

I don't know, gets you thinking.

[wxmann_91]

Droughts in the Plains are fairly common and occur regularly. The last major one was in the 1950's, I believe, and that was only two decades after the Great Dust Bowl.

[x-y-no]

Over the last 4 or 5 years people have begun seriously trying to model regional climate, but I don't know that this effort is very far advanced.

I think the short answer to your question is: it's possible but we don't know that with any confidence. As wxmann_91 pointed out, this drought is nothing particularly exceptional yet.

[Aslkahuna]

Drought of varying degrees occur in the Plains and SW US about every 20 years on average and have done so for as long as they can construct the Climatology based upon Dendrochronology and other studies. The Current one is part of that cycle. The worse ones in modern times have been the 1930's DustBowl Drought, the 1950's Southern Plains Drought and the current one (the 1970's Drought, occurring during a period of positive PDO was less intense and short lived). The current drough actually started in 1996 so has gone on for 10 years with some variabilty which is about typical for these events. The 1950's Drought, which in W.TX and Eastern NM was worse than the '30's, lasted in places until 1961.
The '30's Drought ran into the 1940's. But none of these can even remotely compared to the Drought that led to the collapse of the MesoAmerican and Mayan Civilizations at the end of the 1st Millenium and into the second-in the SW US region that one persisted for 40 years. Technically, GW should result in a stronger SW US monsoon but also in much less Winter snowpack which, in hydrological terms, is far more important than the Summer rains of the monsoon.

Steve

[Matt-hurricanewatcher]

I wish we would just make up our minds.

[Aslkahuna]

Well, I was born in the West and remember the Drought of the 1950's in CA where between 1950 and 1961 all but three years were drier than normal in San Jose-some very dry. The problem from the class that was referenced is that a hypothesis was presented and the wrong conclusions drawn. As I mentioned, droughts in the Plains and SW US are a regular occurrence and have been for a long time one in the 19th Century was referred to as the Great Die Up because of the huge losses of cattle due to lack of feed. Wildfires, they were called Prarie Fires back then were as common as they are now except that they burned unchecked because they usually didn't bother anyone and most large animals could escape them with the small ones going deep underground. They were usually sparked by lightning and would burn for weeks. They only draw attention now because people have built homes in the way of the old fire runs and expect to have them saved without any effort on their parts. It should be noted that Prarie fires are a required part of the ecosystem as they clear out the brush and result in good growth of grass for feed for wildlife. Having established that drought is a way of life in the West, the quesion with regard to GW is what effects would that have upon the cycle and that is what is being studied. FWIW, before we called them the Great Plains, that region used to be called the Great American Desert. The region is classifies as a Steppe type climate which is an arid grassland with an annual rainfall of 12-20 inches and a mean temperature below 18C (Sierra Vista is a Savannah type climate with a storng monsoon signal and is similar to the Steppe climate except the mean annual temperature is above 18C).

Steve