Monday, Aug. 20, 11 a.m. ET

Science: Climate Change and Water Supplies

Doug Struck
Washington Post Staff Writer
Monday, August 20, 2007; 11:00 AM

Washington Post staff writer Doug Struck was online to discuss the impact of global warming on water supplies and the methods being used to maintain dependable supplies for drinking, irrigation, and power on Monday, Aug. 20 at 11 a.m. ET.

A transcript follows.

Read more in the story: Warming Will Exacerbate Global Water Conflicts (Post, Aug. 20). The story is part of The Post's series: In the Greenhouse: Confronting a Changing Climate.


Doug Struck: Good morning. This is Doug Struck, ready to talk about global warming and water. Fire away.


Scottsville, Va.: Unfortunately, much of the discussion on global warming is based on snapshots that vastly oversimplify the situation. For instance, glaciers usually shrink or vanish not (directly, at least) because of higher temperatures but because they are getting less precipitation to replenish them, since melting at the edges is always an ongoing process.

Shifts in precipitation have been occurring for millenia. As you know, the Sahara was once green and there was a huge inland ocean in the United States. Our Southwest deserts are studded with high mesas because their tops were once at ground level but the rains and snows stopped and erosion ate away most of the ground, leaving the harder surfaces elevated.

Two things are rarely recognized in discussions of water shortages in the Southwest, and of global warming:

First, arid conditions have existed in the Southwest for hundreds of thousands of years. Las Vegas, Phoenix and other cities in the region are artificial creations, based on massive importation of water. If its ecology were natural, Las Vegas would have a population of no more than a few thousand, and its economy would be based on arid-ecology sheep and cattle raising.

Second, the real problem for the earth is simply overpopulation. If the planet's population keeps growing, a shortage of water is inevitable no matter how warm or cold it gets. And if that population has access to carbon-producing technology, what we have seen is only a hint of what's to come and all those hybrid cars and other conservation measures will be ineffective.

Doug Struck: You are right that the population of the world is the elephant in the room of the global warming discussion. I don't share your view that it is inevitable that the world's pupulation cannot be sustained, however. A huge amount of fresh water flows from the world's rivers into the sea which could be used before it gets there-- not used up, as all water does continue to exist in some form. And there are desalting technologies in our future.

Glaciers, by the way, are obviously affected by the amount of precipitation they get, as you note. But they are melting largely because of increased temperatures, which are higher at high altitudes. But even if the precipitation stays the same or increases, it may come at the wrong time and fall as rain, rather than snow.


Mt. Lebanon Pa.: Well, we know one thing about the world's total water supply. It doesn't change. The same amount we have now is equal to the amount in the early days of the earth's forming.

The only questions from the top-down view are what form does the water take (i.e., liquid, vapor, clean, contaminated) and where it's located (i.e., surface, atmosphere, subsurface, storage vessel)?

So, who's modeling, measuring, or mapping the movement of ALL of the earth's water resources from a global scale? From that we can find who's going to be the big winners and losers in the water grab 20 years (or sooner) out? The winners get to survive (evolution through natural selection) to reproduce the next generation.

When fresh, clean, treated, and available water costs more than platinum, there might be some hope of controlling the world's human population: the earth's only real solution to the plagues that trouble it, and us.

Thanks much. Registered Professional Engineer

Doug Struck: You are correct about the finite and unchanged amount of water, and correct to say that a complete systematic analysis of where, when and how water will go would reveal all the answers.

Unfortunately, it is far too complex at this point for a very detailed analysis of that type. The huge and complicated computer modeling programs now being used to try to predict the effects of global warming are trying to get at those answers. But how water comes and goes to earth is a function of a million microclimates, and the best they have come up with so far are fairly broad conclusions: naturally arid areas will become even more dry; naturally wet regions will become wetter; more snow and ice on mountains will melt; and more snow will fall as rain.


Connecticut: Our western aquifers are being depleted very rapidly. Corn, a water intensive crop, has become a sacred cow as well.

How do we get American farmers to grow crops that are more sensible for the environment they are grown in?

Doug Struck: One way NOT to do it is increased use of ethanol fuels, which is driving up the price of corn, making it more attractive for farmers to keep growing it in areas that are unsuitable. One way to encourage different choices about land use is to begin putting a price on water, which in many parts of the world is still considered a free commodity.


Columbia Falls, Mont.: The projection for glaciers in Glacier National Park melting was adjusted by park officials this summer from 2030 to 2020, based on their recent studies. Given global warming and emerging conflicts over water, is there any movement towards filtering ocean water and piping it into the U.S. southwest and other areas that are struggling to find water sources?

Doug Struck: The technology is being developed, and is being used in a few places in the world. But it is still considered extremely expensive, and not very suitable for huge water supplies. Yet.


Arizona: In the '70s when there were fewer cars, it was common to get a storm or snow each weekend (in Minnesota) perhaps because there were fewer drivers on the weekends. That clearly related to the human effect. Now we have such a huge number of cars that the atmosphere cannot clean itself as well. We really need that $1 or $2 tax per gallon of gasoline to reverse what is happening.

Doug Struck: Economists will agree that the simplist way of reducing automobile use (and pollution) is to put a huge, or perhaps it could be described as realistic, tax on gasoline. But the economists don't have a place on their ledger sheets for the social costs of such a move.


NYC: I realize my comment will be a bit snotty and sarcastic but it is my way of driving home a point to those who don't believe.

My wife and I have no children, we are older, so no plans either. Only one nephew so our future generations are basically null and void. I tell those conservative types and anyone who questions global warming that we are sucking down as much water and resources we can because I have no vested interest in the future, their children and their grand children. If they want to save their children they better start conserving. This tends to get them angry and thinking. Not sure if it's working but for me, I see walled communities of rich people with swimming pools watching the rest of us die of thirst.

P.S. -- The reality is that my earth foot print is very small.

Doug Struck: No comment.


Arlington, Va.: There has been a proliferation of books recently on resource (particularly energy and water) depletion and population growth and generally how we are coming to the limits of the former, largely due to the latter. Exacerbating the situation are lifestyle choices that particularly we here in the U.S. have practiced, but now other large countries like India and China seek to emulate. Things like moving to the desert in large number in sprawling settlements where most people want irrigated lawns and drive large SUVs everywhere for everything. You explain the situation to any 7-year-old child and they immediately see the folly of it all. So, why do we do it ? And how much sympathy should anyone feel for people who choose lavish, gluttonous lifestyles in unsustainable arrangements as it now all comes to an end? Unfortunately you are correct that conflict is likely to be the result.

Doug Struck: No comment.


NYC: Water prior to the ocean: If we begin to use the water from rivers prior to the ocean will that change the salt concentrations of the oceans and cause greater harm?

Doug Struck: In theory water diverted for human consumption could be returned as fresh or treated water to that river before it exits to the sea. But in practice, there would be considerable loss, and yes, there would be consequences to the salt concentrations in the area of the river's exit.


Fairfax, Va.: Do you expect to see any of the Democratic candidates make global warming/climate change a major issue in their campaigns and in a related question, how much time is left before efforts will be too late?

Doug Struck: How much time is left? The million dollar question.

As to politics, I have been based in Canada for three years. I find it interesting that global warming has become a huge political issue there; in fact, polls show it is the leading concern of voters.

Will that same concern happen in the US?


Freising, Germany: Australia and Calif. seem to be both at great risk of water shortage due to climate change. However, both have access to seawater and could create desalination plants for freshwater supplies.

Nations in the Middle East have been burning oil to create freshwater for years, but this too expensive for most nations. A while ago, I read something about reverse osmosis, which uses permeable membranes to separate freshwater from brine. I'm surprised that a lot more effort hasn't been put into this technology to create freshwater.

Have you heard anything on the viability and implementation of reverse osmosis?

Doug Struck: Such technologies are coming, but I don't know the economies of reverse osmosis.


Washington, D.C.: Very glad to see this piece today. Want to highlight that the lack of access to water AND sanitation is an issue right now. It is the most under-recognized global health problem killing up to five million people each year-- more than HIV/AIDS and malaria.

Also wanted to comment that the reason the over-one-billion people that lack access to water and sanitation right now is not a result of the environment per se, but more so as a result of failure to solve global poverty issues.

We can -- right now-- get water and sanitation to those affected (1.1 billion without water/2.6 billion without adequate sanitation). What is missing is the political will and financial resources. It is doable.

John Sauer

Water Advocates

Doug Struck: no comment


Arlington, Va: I am very happy to hear your opinion on ethanol. Ethanol is perhaps the most dangerous boondoggle swindle in the history of this country. It is dangerous because it preys upon the addiction of Americans to cheap fuel and their hope that it can be sustained (it can't), a boondoggle because Americans will end up paying in taxes large amounts for this uneconomical process while also paying more for food, and it's a swindle because by calling it "green" and being associated with plants, the ethanol lobby has conned some in the environmental movement into supporting it. It's really crazy.

Doug Struck: no comment


Arizona: I wonder if anyone has done a study on airliner flight paths and global warming changes in the ocean? I read one report that the day to night cooling differences was 1.8 degrees better when airline traffic was halted after the 9/11 tragedy.

Doug Struck: I haven't seen that report. I'm sure there are studies. The greenhouse gas emissions of air travel are great. A lot of concerned folks are pledging to offset any air travel they do by buying other carbon credits. Some are trying to limit their air travel-- Vancouver environmentalist David Suzuki, who is in great demand as a speaker, says he will agree to all speaking requests next year only if they do it by video teleconferencing, to avoid the pollution caused by air travel. But it's pretty unrealistic in this day and age to think air travel will stop. What we need to do is find ways to do it with less harmful consequences.


Arlington, Va: Water and energy are really converging catastrophes, aren't they? A good example is the Canadian tar sands that have huge pressures to develop (due to insatiable appetite for oil), but that take enourmous amounts of water to extract the tar from the sand. I believe there has been many articles in Canadian papers on the Athabasca River water problems due to the mining of the tar.

Doug Struck: And articles in the Washington Post, I might add. The tar sands in Alberta are a good example of the contradictions you mention. Aside from using water from the river (the oil companies say they return almost all of it in pristine condition, but that's not what the First Nations folks who live there say), the process of squeezing oil from the sand requires enormous amounts of natural gas. It's not terribly efficient in terms of energy, and it is the biggest single source of greenhouse gas emissions for Canada. Many oil producers-- and the federal and provincial governments that are swimming in tax revenues because of the oil sands projects-- are worried that the greenhouse gas emission problem could be the ultimate death of the oil sands projects. The oil companies say that technology will save them-- they will find ways of getting the oil without using so much natural gas or water. They are making progress in that direction, but is it enough...? As the television reporters say, time will tell...


Cincinnati, Ohio: Doug,

Did any of your investigations lead you to any insights on the future of water economy, investments, water rights, etc.? I would hope for conservation and adaptation, but if not, water could be a major contributor to a long time line investor, but how?

Doug Struck: I'm no oracle. My own suspicion is that water, like any scarce resource, will become more and more allocated as a commodity with a price. Economists will say that is an efficient way of encouraging conservation and adaptation, and indeed it may do so. But it also means those with money win the game, and those without lose. And the game may mean life itself.


Washington, D.C.: As the atmosphere warms and the capacity for water contained in it increases, wouldn't this lead to more precipitation? And if so,wouldn't this lead to more plant growth? And more plant growth can lead to less C02 in the air...right? Is this a scenario that is incorrect?

Doug Struck: Yes and no. Unfortunately, in the world, we are cutting down huge swaths off the natural plant growth-- the forests-- that have buffered the CO2 exchange for eons. Secondly, the amount of carbon dioxice we are pumping into the atmosphere is overwhelming the balance, even if the plants were there. And thirdly, the increase in precipitation may not be in a form very beneficial to plant growth: floods and torrents. NASA has already documented the increase in "gully washers," torrential downpours that do more to erode than to foster plant growth. And if the glaciers-- natural storehouses that have "watered" plants below for ages-- shrink so much that the runoff ends in the summer, we will have more desertification, not less.


Arlington, Va.: Any serious work being done on modeling, thinking about impact of climate change induced global migration? Certainly capable of destabilizing all of the industrialized West, as well as the developing world. Yet how to talk about this without sounding alarmist, nativist, or worse?

Doug Struck: One of the questions we set out to investigate in this series of articles was the prospects of global migration. I found, as your question suggests, that there is little but the broadest warnings and guesswork. I think scientists shy away from trying to predict human nature. But yes, at the risk of sounding alarmist, there are huge risks to those who live in areas of plentiful resources, be they water or energy or temperate climate or food, from the millions who may find themselves without some of those resources as the climate change. The United Nations Secretary General caused a bit of a stir by stating even the most obvious-- that global warming and the shortage of resources is at the root of conflicts in Africa already. You are right that it sounds too alarmist to discuss, but reality will prevail. We in the U.S. already have witnesses massive migration during the Dust Bowl drought and depression.


Washington, D.C.: Doug, In your article you make the connection -- I believe -- that 1.1 billion that lack access to water as a result of the environment. I'd like to suggest that this is rather a result of failing to address, head-on, global poverty issues.

We know how to solve this problem -- we just don't have the resources and the political will to do it.

What are your thoughts on this issue and are you planning on exploring them in more detail in future articles?

Thank you.


Doug Struck: There is no doubt that poverty, population, use of resources and global warming's effects on those resources all go hand-in-hand. In China, for example, the rapidly worsening water shortage is a consequence of melting glacier, booming population, economic development that requires more water, and hugely polluting industries that are poisoning the groundwater. Is any single cause to blame? No-- it's all of them.

That is exactly what makes predicting these outcomes difficult: as our environment changes, humans react, for good or bad. Will we react by embracing conservation or developing alternatives to the greenhouse gas-producing technologies we all rely on? Or will we pick up a gun and fight over what's left? I suppose that depends on how much confidence you have in human rationality.


Frederick, Md.: A few months ago, I read that the scientist who, back in the 1960s, first warned that global warming was a threat, said recently that it's too late to do anything about it and that all we can do is adapt as best we can. What does this gentleman say we can expect over the next 100 years?

Doug Struck: I don't know to whom you are referring. Many scientists talk of the "tipping point" at which we will no longer recover the ecological balance we had, with potentially disastrous results. And some believe we can no longer avoid that consequence, and the only choice we have is to "adapt" to whatever comes. I personally feel that's a bit irresponsible. We could make some pretty significant changes in how we live and how we pollute our world that can at least mitigate the pain, if not avoid it entirely.


Menomonie, Wisc.:

I just wanted to thank you for your excellent article. While much has been said in the media about countries going to war over oil (which is true to some extent), little has been said about countries going to war over water. I agree. Water will be our next resource that wars will be fought over.

In an earlier post, someone commented that water will not run out. That may be true. But potable (drinkable) water could run out due to the effects of global warming.

Again, thank you...

Doug Struck: Thanks.


Virginia:"And the game may mean life itself."

But, it seems it isn't a big issue in the presidential debates. If it were so important wouldn't they be discussing it, rather than whether Obama is black enough or how many wives Rudy has ?

Doug Struck: I have no dispute with that logic.


Reston, Va.:

Bottled water is part of the problem, not any solution.

This is one of the biggest frauds in history perpetrated on the consuming public. To be sure, there are places on Earth where you had better drink bottled water. And better make sure you crack the seal on the bottle's lid, to ensure you haven't just been sold a discarded bottle refilled by local street urchins, refilled from some public tap. While water quality does vary slightly across the U.S., given the standards applied by water purification plants here, you're probably safe simply ridding kitchen tap water of fluoride and chlorine using some basic charcoal filter pitcher.

There are many good reasons not to drink bottled water, unless to avoid arsenic or dysentery. Financially, the water you just paid hard-earned money for is typically no healthier than your tap water, and in fact, that's where much of it comes from. Regarding personal health, plastic bottles leach antimony, which is linked to various neurological disorders. (Google "bottled water" and "antimony," and read away!)

But how does bottled water harm the environment? "Each year, (Americans) throw away 30 billion empty water bottles. That's enough to circle the earth not once, not twice, but 150 times. 4 out of 5 plastic water bottles end up in landfills. But even before they get there, they've taken a toll on the environment. To get to (a) store shelf in Chicago, a bottle of water from France must first travel more than 5,000 miles on ships and in trucks. And water is heavy, so transporting it requires a lot of fuel. ... Even before you drink (a) bottle of water, you've already consumed about 2 ounces of oil, and that doesn't include the oil used to make the plastic. The entire process creates greenhouse gasses. It's ironic that on some of these bottles' labels you see snow-capped mountains and glaciers, when in fact, production of the bottle is contributing to global warming, which is melting those snow caps and glaciers. Compare that to tap water, which is delivered using little or no oil. New York City's water, for instance, flows by force of gravity, no energy consumed." Several U.S. city governments are refusing to purchase bottled water, and restaurants have removed it from their menus, serving filtered tap water instead. (Source: "Bottled Water, Wasted Energy?" ABC Evening News, July 8, 2007)

Doug Struck: no comment


Cedar Grove, Md.: As was stated previously, weather patterns have been shifting for hundreds of thousands of years. Glaciers grow then retreat. Oceans become deserts.

The debate is between correlation and causation, and the problem with the debate is that we lack true benchmarking data? Are there any highly regarded (pre-debate) scientists that postulate that the earth just does this every 10,000 years, or somesuch? I mean, if the population of Buffalo triples in 50 years, as does the population of herons that live on a nearby island, it doesn't follow that the increased number of herons caused the population increase in Buffalo.

That said, the evidence sure SEEMS damning.

Doug Struck: In terms of "highly regarded" scientists, the Intergovernmental Panel on Climate Change is a nearly unprecedented effort to glean conclusions from thousands of the top scientists in the world. The series of reports that has emerged from this exhaustive collaboration is conservative, cautious, documented by massive research, un-alarmist in tone, and should be convincing to us all. They have concluded man is causing an increase in the temperature of the earth's atmosphere that is unprecedented for man's history. They have concluded it will have drastic and far-reaching effects on our world, our water, our energy, our food, our health, and our lives. They also have concluded we have the means to try to reduce those impacts.

For the vast bulk of the scientific community, those questions are now settled. And "highly regarded" scientists are frustrated that all of that expertise seems offset by a few naysayers. There will always be those who disagree. Unfortunately, many critics are tainted by their funding sources; oil companies are hiring "regarded" scientists to defend their financial interests, just as the tobacco companies did to answer evidence of the smoking-cancer link.

Has the world gone through drastic climate changes before? Sure. And dinosaurs died out as a result. It seems to me the prudent choice is not to argue about what might have happened before man came on the planet, but on how we can change our own behavior before it kills us.


Doug Struck: That's all for now. Thanks very much for all your thoughtful questions. Keep reading for more of the global warming series on the Post's science pages.

-doug struck


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