Originally Posted By mrkthompsn How much has the sea risen in the past 30 years? Neat fact: the total population of the earth today - every man, woman and child - can physically fit within the city limits of Jacksonville, Florida.
Originally Posted By jonvn Here, go read up and give us an executive summary. <a href="http://yosemite.epa.gov/oar/GlobalWarming.nsf/content/ResourceCenterPublicationsSeaLevelRiseIndex.html" target="_blank">http://yosemite.epa.gov/oar/Gl obalWarming.nsf/content/ResourceCenterPublicationsSeaLevelRiseIndex.html</a>
Originally Posted By DlandDug Funny, I seem to recall reading this story somewhere else. Somewhere... a little less hysterical: EXCERPTS: >>A year ago Lake Powell reached its lowest level since Jimi Hendrix played Woodstock and Neil Armstrong made his giant leap onto the moon. A sustained drought had sucked out two-thirds of its water, exposing 140 vertical feet (42.7 meters) of once drowned cliffs. The dry spell temporarily turned the great reservoir back into a red-rock maze called Glen Canyon, stirring hopes that terrain whose grandeur rivals any on Earth may one day be revealed for good.<< >>After Glen Canyon Dam closed its gates on the Colorado River near Page, Arizona, in 1963, the river's cargo of snowmelt and spring rain, gathered from much of the mountain West, hit the dam's concrete stopper and began to pack up. The rising waters slowly transformed the lower reaches of the intricate, thousand-hued Glen Canyon into a monolithic blue-green reservoir, the country's second largest after Lake Mead, farther down the Colorado. Aided by Lake Powell's aqueous bounty, Little League fields sprouted in Las Vegas, subdivisions multiplied in Los Angeles, golf courses carpeted Phoenix. As the reservoir waters rose, Glen Canyon drowned.<< >>Then came the sustained drought that ushered in the 21st century, one of the region's periodic dry spells. For five years clouds yielded little moisture, even as the West continued to drink greedily. The Colorado River, lifeblood for seven states, dwindled. Lake Mead and Lake Powell, the river's massive catch basins, shriveled. No amount of hydro-engineering, cloud seeding, flow regulating, or other manipulation could change a simple fact: Not enough water was falling from the sky to keep the West's reservoirs full. Not with the increasing number of straws sucking upstream water to irrigate alfalfa fields, fill swimming pools, and sprinkle suburban bluegrass expanses. Lake Powell's loss was and is Glen Canyon's unmistakable gain.<< So it seems that what's really happening is a man-made reservoir is failing to reliably perform, based on "one of the region's periodic dry spells." Not nearly as sexy as, "Lake Mead is drying up and we're to blame!" Then again, this could just be propaganda from those right wingers at... The National Geographic magazine (April, 2006). <a href="http://science.nationalgeographic.com/science/earth/surface-of-the-earth/glen-canyon-revealed.html" target="_blank">http://science.nationalgeograp hic.com/science/earth/surface-of-the-earth/glen-canyon-revealed.html</a>
Originally Posted By jonvn Never mind. I did it for you: Sea-level has risen about 130 metres (400 ft) since the peak of the last ice age about 18,000 years ago. Most of the rise occurred before 6,000 years ago. From 3,000 years ago to the start of the 19th century sea level was almost constant, rising at 0.1 to 0.2 mm/yr. Since 1900 the level has risen at 1 to 2 mm/yr; since 1993 satellite altimetry from TOPEX/Poseidon indicates a rate of rise of 3.1 ± 0.7 mm yr. Church and White (2006) found a sea-level rise from January 1870 to December 2004 of 195 mm, a 20th century rate of sea-level rise of 1.7 ±0.3 mm per yr and a significant acceleration of sea-level rise of 0.013 ± 0.006 mm per year per yr. If this acceleration remains constant, then the 1990 to 2100 rise would range from 280 to 340 mm. Sea-level rise can be a product of global warming through two main processes: thermal expansion of sea water and widespread melting of land ice. Global warming is predicted to cause significant rises in sea level over the course of the twenty-first century.
Originally Posted By jonvn "The National Geographic magazine (April, 2006)." Yes. Let's go to something about a year old as opposed to something more recent. Well, that's always handy if you don't care about advances in understanding.
Originally Posted By fkurucz <<So it seems that what's really happening is a man-made reservoir is failing to reliably perform, based on "one of the region's periodic dry spells." Not nearly as sexy as, "Lake Mead is drying up and we're to blame!" >> Its a bit of both. Yes, cyclic drought conditions. But since we knew about that, maybe, just maybe, we should have discouraged population growth in the SW? Usually land can't be subdeveloped unless there is water allocated for it. Perhaps had we not been so keen on building a zillion new houses in the SW, then maybe, just maybe, this situation might not be so dire. Also, I think that its high time we restrict immigration (of all kinds). If we are struggling to cope with droughts when our national population is 300 million, what is going to happen when we reach 400 or 500 million? Maybe its time to turn on the "No Vacancy" sign.
Originally Posted By mrkthompsn Seems like not only is the sea level rising due to thermal expansion and ice melt, but also from the absense of water on (and inside) dry land. Three sources. (which means it's worse than just ice melt)
Originally Posted By mrkthompsn <Let's see . . . Phoenix, Los Angeles, Denver, essentially every other city in the Southwest. It's not like this should be unexpected. The Colorado River doesn't even make it to the ocean anymore. It just disappears into the sands of Mexico now that all the water's been diverted to so many other places. >> Water doesn't disappear. Where does it go after Phoenix, Los Angeles, Denver, essentially every other city in the Southwest?
Originally Posted By Sport Goofy Set a glass of water out on your counter at home. After several days, weeks, the glass is empty. Where did the water go?
Originally Posted By Mrs ElderP Fundamentally, here in the west, but also now in the south east there is not enough water to sustain us at the water levels we're used to. Less people is one solution, different lifestyles is another. If nothing else market forces and the invisible hand are ready to solve the problem, but their solutions are painful. Expensive water is just as painful, if not more so than expensive gas. Eventually water will get so expensive de-salination will become more practical, as well as other purifing efforts.
Originally Posted By fkurucz <<Water doesn't disappear. Where does it go after Phoenix, Los Angeles, Denver, essentially every other city in the Southwest?>> The Colorado is being sucked completely dry by human consumption. For those who live in the eastern US this can be hard to comprehend. Rivers in the western US are few and far between. They are also tiny compared to rivers like the Missouri or the Ohio.
Originally Posted By fkurucz ^^^Oh, I see, you mean what happens after it get flushed down the drain? A great deal is lost to evaporation: lawn watering, swimming pools, etc. In hot climates like those found in the SW that can be the lions share. In some communities sewage is treated so that it can be used for irrigation. There is news that in Orange County they are planning on pumping treated sewage into the water table, with the hope that it will absorbed (an purified) by aquifers. Desperate times call for desperate measures. But at the end of the day it all boils down to the fact that the SW is using more water than nature is providing. And with the SW population expected to continue booming I expect that measures will become even more desperate.
