A 2008 study shows that Earth’s changing climate has caused available water to shrink in the western U.S. during the last half century.
And even bigger changes lie ahead, according to lead author Tim Barnett of Scripps Oceanographic Institution in San Diego.
Tim Barnett: It’s a 20 percent decrease on average over the western U.S. in the snowpack as it exists on the first of April.
Barnett’s study compared 50 years of river and climate data with computer models. It showed that in the western U.S., about 60 percent of changes, such as shrinking snowpack, can only have a non-natural explanation: a human-induced rise in temperature caused by greenhouse gases. Barnett added that water supplies in the western U.S. might be disrupted within 20 years.
EarthSky asked Barnett how people will adapt.
Tim Barnett: Some of the adaptations will be conservation. Some will be taking it from farmers and giving it to a growing population. A decent adaptation would be to limit the population growth and development in the western United States. I don’t think that will ever happen. But those are the kinds of things that we’re going to have to do.
Barnett is concerned about the environmental future we’re leaving for the coming generations.
Tim Barnett: We’re altering the climate of planet in ways that we know, and in lots of ways that we don’t know. We’re making a world for today’s children and grandchildren that they’re going to have to live in, in the future. And if they don’t like it, there won’t be a thing they can do about it.
Barnett warns that dam capacity will be insufficient to hold the water coming rushing down.
Tim Barnett: What it means is that the bulk of your water that you receive, say from the melting snow, is going to come in the first three months of the year: January, February, March. By the time that you get to April, you’re largely out of snow in many areas. So what happens then is that you have to have enough dam capacity to hold all that water that comes – swish – down there in the early part of the year. If you don’t, you have to let it go. In the case of California, and in the case of the Columbia basin, they do not have the dam capacity to capture all of that water. So a lot of good water that we could use will go to waste.
How does Barnett’s study show this climate change is human-caused, rather than part of a natural climate cycle?
Tim Barnett: Well, of course that’s the trick. We do compare the signal, the fingerprint, with that we get from natural variability. We estimate natural variability from computer models. We think, from the computer models, that we’ve got a pretty good idea of what the natural variability of a system is like. We then compare that with what happens when you add greenhouse gases into the model. And they’re just night and day. They just don’t look alike.
What does he expect of water supplies in the American west over the coming two decades?
Tim Barnett: Things will get increasingly tighter, and tighter, and tighter.
Our thanks to:
Tim Barnett
Research Marine Physicist
Scripps Institution of Oceanography, UCSD
La Jolla, CA
Image Credit: William and Lisa Roberts
Humanity cannot make an atoms smaller. If you mean aquafers and like. The Edwards aquafer had gotten lower not because it is “HOT” but because the demands on it has increased. Phoenix is hot and water is scare there because it is a desert. When a person moves there from out of state, the first thing they want to do is make their lawn “Green” like it was from where they came from.
I am appalled that Tim Barnett can seriously claim:
“… about 60 percent of changes, such as shrinking snowpack, can only have a non-natural explanation: a human-induced rise in temperature caused by greenhouse gases…”
Only a non-natural explanation?? As if there were never dry periods in North America before—long before man. 50 years is a mere spec of time and claiming that declining precip is mainly the result of man is utter nonsense. There is NO basis on which to make that claim. Climate changes. Precipitation changes. Always has and always will.
Keep going, Dr. Tim Barnett. Your work as well as as the great scientific research being given attention by Earth & Sky deserves widespread consideration and discussion. If one voice in the wilderness matters, please know I believe you and the other fine scientists featured on the EarthSkyBlogs are somehow pursuing a track that in the main appears correct.
Steven Earl Salmony
AWAREness Campaign on The Human Population, established 2001
As a Central California farmer I’m not thrilled that Dr. Barnett takes it for granted that one of the solutions for shrinking water supply is “to take it from farmers and give it to a growing population.” Who will feed this increasing mass of humanity? And where is it written that population growth and development could/should not be limited? sk
Dear Shirley,
At least for me, you are asking really good questions. I wish there were easy answers to the questions you raise. If there are quick fixes to the problems you are seeing, they have not yet come to my attention.
So many people are quick to speak declaratively about the human predicament all of us are beginning to confront; whereas, remarkably few people have incisive questions to ask, as you are doing. Thanks for questioning what we are doing, where we are going and how we are going to get there.
Sincerely,
Steve
Steven Earl Salmony
AWAREness Campaign on The Human Population, established 2001
The west is a naturally dry region; water and its availability has always been an issue. Why do think so many Native Americans abandoned their civilizations? No water. Populating the west was merely bad timing and bad luck. When the majority of the initial settlers moved to the west, the west was experiencing a wet spell. Then it dried up again. Have we forgotten the black blizzards? The west will become dry again. The people who live there will have to leave. The little water that will be available will have to be reserved for the farmers. Without them, our ever-growing population will not survive. Thinking that we can tame and manipulate nature to sustain us is pure ignorance on our part. If Mother Nature does not choose to support life, life should not be there.
The “Climate Change” argument has become a crutch which encourages lazy science. Those who are too stupid or lazy (same as stupid) to pursue scientific method relentlessly, almost always claim the same tired conclusion of “man made climate change”. How about a little diligence in trying to disprove your theories in order to prove them? You may not achieve instant notoriety, or find that your theories are always true, but at least you can sleep soundly in knowing that you have put in an honest effort in ensuring that science is being used for the education and the betterment of mankind.
Meteorologists cant predict accurately the weather to the next hour. You try to predict 50 years into the future. The sea levels rise 1 mm and you blame it on humans. The weather becomes warmer. Also blame it on humans. The acidity of rain water increases. You also blame it on humans. Antarctica is melting a little.Also on humans. The hole in the ozone layer in antarctica (where no cars ever drive) you also blame it on humans doing something. How come you never research other possible things. Youve been blaming humans for all this for a couple of decades and have not aqcuired enough proof of it still.