UniSci - Daily University Science News

It's too soon to know for sure, but some climate experts suspect we're shifting into a new phase of the Pacific Decadal Oscillation (PDO). This is a long-term Pacific sea temperature and sea surface pressure pattern.

If these climate experts are right -- and it may take another 10 years of data-gathering to settle the question -- the American Southwest could be poised at the beginning of a drought that could last 10 years or longer, says Barbara Morehouse.

Morehouse directs the University of Arizona's Climate Assessment Project for the Southwest (CLIMAS), a program in UA's Institute for the Study of Planet Earth.

CLIMAS researchers have analyzed how a drought similar to the Southwestern drought of the 1950s would affect Phoenix and Tucson water supplies in the year 2025.

The Pacific Decadal Oscillation is a fairly regular pattern of high and low pressure systems over the northern Pacific Ocean, off the coast of Alaska and Canada. The PDO operates on a 20- to 30-year time scale -- much longer than the better-known but short-term El Niqo and La Niqa events. Shifts in the PDO regime occurred in 1925, 1947 and 1977. Some climatologists believe that the PDO shifted again around 1995.

Researchers know that the PDO correlates with relatively wetter and drier periods in western North America, Morehouse said. And new research by University of Washington climate researchers suggests that the PDO enhances El Niqo and weakens La Niqa conditions in one phase, then weakens El Niqo and enhances La Niqa conditions in its alternate phase.

Since 1977, as the new research would predict, the American Southwest has been blessed with wetter winters during El Niqo years and not-so-dry winters in La Niqa years.

Winter precipitation is nature's major means of watering this region. So if the PDO did indeed shift to its alternate phase in 1995, Morehouse notes, the Southwest may be short on renewable water for the next several decades.

How severe that drought will be and how long it will last still is not clear.

Most of the Southwest experienced a prolonged and severe drought during the 1950s, Morehouse noted. If a drought of that magnitude and duration occurred today, "the consequences could be at least as severe," she said.

CLIMAS scientists have modeled the effects of prolonged drought on urban water supplies in Phoenix and Tucson based on the 10-year drought conditions that occurred in the 1950s and the Arizona Department of Water Resources estimates of Phoenix and Tucson water needs in 2025.

Even assuming full availability of Central Arizona Project (CAP) water, Phoenix' water demand could exceed its renewable water supply by 39 percent, according to CLIMAS. That is a 15-percent increase above the 24-percent overdraft already projected for Phoenix for 2025, Morehouse noted.

Tucson is projected to have a 15-percent groundwater overdraft in the year 2025. A 10-year drought comparable to the 1950s drought would increase that deficit by another 10 percent, according to the same CLIMAS study.

"In raw numbers, this would translate to an additional 3.78 million acre feet of groundwater overdraft for the Phoenix area over the next ten years, and an additional 380,000 acre feet of groundwater overdraft for Tucson during that time period," Morehouse said. "These are significant amounts of water, especially given current infrastructure and water policy considerations in the two metroplexes.

"The Tucson/Phoenix area has experienced considerable growth and change in the past several decades, a time when conditions have been relatively wet. Assuming that these conditions will continue into the indefinite future flies in the face of everything we have learned about the ancient and recent climate history of the Southwest.

"We all should begin thinking seriously about the impacts of extended dry conditions, about what viable alternatives exist for coping and what contingency plans we need," Morehouse said.

The CLIMAS project is funded by the National Oceanic and Atmospheric Administration. [Contact: [3]Lori Stiles, [4]Barbara Morehouse] 3. mailto:lstiles@u.arizona.edu 4. mailto:morehoub@u.arizona.edu 04-Feb-2000 Copyright ) 1995-2000 UniSci. All rights reserved.

TO SYSOPS: I notice the directory includes topics such as "chemtrails" and "EBN news", but no category for environmental issues and concerns, which many of us consider important potential TimeBombs in the years 2000+.

-- (First=Last@Last.=First), February 04, 2000

Answers

A lot of people have dismissed the book "The Coming Global Superstorm" because it was co written by Art Bell but the book is full of facts and information about the climate changes to look for and the results of the changes. If you don't have the time to gather the facts then this book would be a good source.

-- Carol (glear@usa.net), February 04, 2000.

Weather has been strange here on Kaua'i this past year or two. Periods of intense rain and periods of no rain...instead of some rain almost daily...

-- Mad Monk (madmonk@hawaiian.net), February 04, 2000.

Thanks I live in Tucson and this is the frist I've heard.

-- Juan Valdez (vgd38@hotmail.com), February 04, 2000.

Thanks I live in Tucson and this is the first I've heard.

-- Juan Valdez (vgd38@hotmail.com), February 04, 2000.

I am 44 and have lived in middle Tennessee most of my life. Last year was the first in my memory when established trees died from drought. Not talking about the odd diseased or old tree. Healthy trees, and many of them, in my yard and surrounding woods. Also occurred at least in an area a hundred miles west, inclusively, from here. Young and old alike; Oaks, Virginia Cedar, Elms, Hickories, etc. We have had droughts with leaves dropping early, but coming back fine the following year. Not this time...just standing dead wood. Just an observation from my little neck of the woods.

If anyone else in this and surrounding states would like to share their observations I would appreciate hearing them. It was stressful for me seeing so many beautiful trees die in an already stressful year.

Slightly OT...big snowstorms predicted for this area last week when other areas were hit.....never got so much as a flake. It was supposed be a three day snowfall. (Shoulda posted this on that thread about the new weather computers but I must have been to tired or lazy)

-- Kyle (fordtbonly@aol.com), February 04, 2000.

Kyle,

That's terrible. I'm so sorry. Last summer we had a bad drought the first part in NYC--very unusual. Finally it rained, but it had become quite worrisome in regard to the poor trees. I guess they usually can hold their own...

-- Mara (MaraWayne@aol.com), February 04, 2000.

Thanks Mara, not TEOTWAWKI just based on last year's drought. But, as sad as it was, I don't forget the folks who suffered the unusual(?) floods: NC, SA, and some others I can't remember now. That had to be much worse. I saw some very pretty trees die. I can't imagine how horrible it was like for those affected by those floods. I just hope New Madrid hits after I am gone.

-- Kyle (fordtbonly@aol.com), February 04, 2000.

Bruce Sterling's book "Heavy Weather" comes to mind.

-- Boy M.I. Dry (seeya@the.river), February 04, 2000.

Since we seem to be, neighbors talking to neighbors, I offer this weather information from my small plot. I have lived in Florida, since 1969. We ALWAYS had daily summer showers. Things changed, over two years ago. No rain, just the forest fires, from lack thereof. Delve into your memory bank of newscasts. It was hell on earth, from our human fear, of the fires. Smoke in our neighborhoods, see it, smell it, taste it. I lived it.

-- Back to (fillingw@terbottles.com), February 04, 2000.

Patrick, Forget the money,use it to re-hydrate! Buy lots of bottled water,drink it often and you might just be successful in increasing your shrunken brain mass,After all the brain is more than 80% water

-- Doc Feelie (better health@waterbottle.com), February 04, 2000.

Patrick...

.....Find a new handle if you're going to hang around, I don't want people confusing me with your idiocy.

-- Patrick (pmchenry@gradall.com), February 05, 2000.

Kyle, we live in Missouri and last summer we lost three big oak trees and two dogwoods, and our neighbors lost seven oaks. This is very scary. In fact I've always been more worried at the degradation of the enviornment, especially water, than I have been about Y2K.

Many of our Y2K preps were more for future enviornmental problems than for Y2K. Last summer was one of the driest summers we've had, and the heat was horrible. I started using a dishpan again, saving my "gray water" for plants. We also used soaker hoses in the garden as they use less water.

Thanks everyone for book suggestions; here is mine. The Heat Is On by Ross Gelbspan. This book is a must read for those who think global warming is just a big joke or hoax. It will take off your blinders.

SYSOPS: I too think we need a topic on the environment. After all this is the only home we have.

-- gilda (jess@listbot.com), February 05, 2000.

I have my doubts about global warming. Why has the frost line headed further south in Florida in recent years. Is it not true that oranges can't be grown as far north as in the past? That sure doesn't sound like global warming to me.

-- Kyle (fordtbonly@aol.com), February 05, 2000.

You can blame it on poor people, white-trash, liberals, or big government or you can grow up and act to constrain your consumption. We have the power to save the planet.

Buy a smaller car, build a smaller home and give the savings to a school or better yet, support free education and health care for all. Live within your means.

Buy organic food and build with Smartwood sustainable harvested lumber.

Support all forms of population control, yes including abortion in the first two trimesters.

Turn the lights out, turn off the TV, permanently. Turn down the heat to 60% and buy a warm down comforter.

Move out of your phoney cowboy, suburban, lifestyle and move to a city. Better yet -- convert a wasted city into a garden.

Ride share, better yet live close to work and walk or ride a bike.

Build trains, bike paths, green-belts, city vegetable gardens. Take power for the sun and the wind.

Get a life and give up on the crap.

Pete

-- Peter Starr (startrak@northcoast.com), February 05, 2000.

Kyle,

I've always thought you were more intelligent than that. Offering anecdotal local evidence, in contradiction to the massive body of available evidence to the contrary, is beneath you. Last summer in the American southwest was among the coolest recorded; in Russia, Europe and the Eastern US, among the warmest.

Earth's climate is a complex system, it's effects are neither linear, obvious nor intuitive. Brighter minds than yours, mine, Gore's or (especially) Bush's are seriously investigating the global warming phenomenon.

The consensus of "independent" scientific opinion is that the "average" temperature of both the atmosphere and the oceans is rising. There is little serious debate on this observation, only on the amount. Mankind's percentage contribution to warming is at issue only in the matter of degree.

If you wish to contribute seriously to this debate, you're going to have to do a lot better than repeating corporate propoganda or anecdotal observations about oranges.

-- (First=Last@Last.=First), February 05, 2000.

Kyle, When it barely freezes in northern Minnesota and the frost line is moving towards the south at the same time, I'd say that things aren't going too well. Here it is, already Feb. and I have driven a rear wheel drive car ALL winter. For someone not from Minnesota here that might sound o.k., but around here you can COUNT on having school closed, missing work, getting stuck, having massive six foot drifts cover your driveway, etc. at least a few times every winter. Right now we have about two inches of snow, and it just snowed! Wanna know why? Because right before that most of the snow recently melted when the temps got above freezing for the umpteenth time. I promise that this is not normal weather. By the way, all the roads around here are starting to crack from lack of moisture in the ground. All is not well.

-- J (noone@the.door), February 05, 2000.

Kyle,

It seems that some folks regard pure nonsense, such as: "The consensus of "independent" scientific opinion is that the "average" temperature of both the atmosphere and the oceans is rising.", to be preferable at least to some anecdotal reports. On the other hand, anecdotal reports which may be viewed as supporting certain opinions often get warmly received. :-)

Jerry

-- Jerry B (skeptic76@erols.com), February 06, 2000.

The weather has always been cyclic, but very few people have seen a full cycle. If the scientists are right on this and we go back to the 1950s and 60s style storm cycles, then it will still be almost another ten years before we return weather like when I was a small child. And I'll be over fifty years old by then by then, too.

I still recall second story-high snowdrifts in Virginia from the late 50's and 60's. Are we ready for twice as many people to have to get through such storms?

I worked with an older guy from northern Florida several years ago. The weather was a common topic in the flying business and the subject of long-term patterns came up. He recalled that as a child near Tallahassee, FL he saw something on his grandparent's farm he had to ask them about.

It was a horse-drawn sleigh. Seems that during the mid 1800's snows severe enough to require the use of sleighs were common in that part of the country. Imagine the Gulf Coast of Florida regularly having those kind of winters.

Think we could be headed towards that type of weather over the next generation? Like some of us recalling the big snowstorms of our youth, will our kids be telling their grandkids about the warm winters of their youth, as they watch the snowflakes fly in Tampa for the umpteenth *@#%!! time that year?

WW

-- Wildweasel (vtmldm@epix.net), February 06, 2000.