April 16, 2012
Climate change and the hydrological cycle
A severe change in the hydrological cycle is expected, and it is expected to hit snow- or ice-dominated areas most severely. This change is expected because of an increase in greenhouse gases. This change at first was expected to increase the amount of potable water but now the dynamics of the changes have been analyzed more closely. We have found out that as temperatures increase less precipitation will fall as snow and snowmelt will occur sooner in early spring and not in the summer or autumn when the water is needed most. The snowmelt and rain will cause an overflow in rivers and causing loss of potable water to the oceans when there are not sufficient reservoirs.
And it is not necessarily changes in precipitation that causes all this because the amount of precipitation generally remains the same. It is the change in temperature that changes the seasonal runoff patterns in these snowmelt-dominated areas because less water falls as snow and more falls as rain, preventing the normal release of water as snowmelt and the quick flowing of rainwater.
The Colorado River of the western United States was determined to be one of the four snowmelt-dominated rivers that also do not have sufficient reservoir capacity to prevent overflow and loss to the ocean. To determine these, first the snowmelt-dominated areas were determined by the ratio of accumulated annual snowfall to annual rainfall and those with R greater than 0.5 were considered snowmelt-dominated. Next, to determine reservoir capacity, the runoff was compared to the reservoir capacity. These determined areas underestimate the area and population affected because populations downstream and other farther areas also depend on the water that comes from snowmelt-dominated areas.
The aspect of the most importance is water supply. In the Western United States, the Colorado River is the most important contributor of water supply. There are no predicted changes in precipitation, only a change in seasonal snowpack and snowmelt, as discussed earlier. The winter snow is expected to decrease and the melting is expected to occur a whole month earlier. On top of that, there is currently not enough reservoir capacity to prevent water loss to the ocean.
The Colorado River, along with the Rio Grande and San Joaquin, supply water to Wyoming, Colorado, New Mexico, Arizona, Nevada, California, Utah, Texas, and parts of Mexico. These rivers, especially the Colorado River, were determined by the Interior Department in 2011 to deplete by 8 to 14 percent over the next 40 years. But in a more optimistic short-term study done in 2009 at the University of Colorado at Boulder, the risk of the Colorado River depleting its reservoirs remains below 10 percent at least through 2026. It was also said as a result of this study that even if the worst drought scenario were to occur, we wouldn’t feel the effects immediately because we have a great storage capacity along the Colorado River, storing almost four times the annual flow of the river. But in between 2026 and 2057, the risk of reservoir depletion increases seven times.
These studies on the Colorado River can comfort us because we know we are relatively safe until 2026, but 2026 is approaching fast and we cannot get comfortable. Large scale changes such as shift in seasonal snowmelt and decreasing amounts of snowfall took decades to develop and will take decades to reverse, if it is even at all possible. The most plausible solution for now is that we must find ways to direct and store this precipitation so we do not lose it to the ocean.
This post was authored by Alejandra Rocha ’12, a senior majoring in Environmental Studies.
We do face real issues of water availability, and, as you mentioned Alex, a lot of our problems may come from the increase in precipitation rather than snowmelt, which releases waters slower. When water flows to the sea without being captured or sequestered, such a circumstance will surely bring up bevies of political debates arguing water prioritization and allocation. This dilemma reminded me of the predicament we face regarding the delta smelt, the fish we talked about in class that is endemic to the Sacramento-San Joaquin River Valley. Just as with increased runoff rates, we are allowing the water run out into the sea for the delta smelt, but in this case farmers are not allocated any water to irrigate their withering crops. It is distressing to think we face more pragmatic decisions that may compromise the well-being, or even the existence, of other species living among us. Good post Alex!
I am so impressed with the Colorado River. I am in awe of how vast it is and how it can supply so much water. Over spring break I did a road-trip/camping trip to the Southwest and got to see a large portion of the journey of the Colorado River water. I drove on the 89 on a bridge over Lake Powell where Arizona meets Utah. At Lake Powell, there is a huge dam and area where they store water – so although there is not enough reservoir capacity to prevent overflow loss to the ocean as Alex put it in her blog post – there are some storage capacities in place. The dam at Lake Powell regulates how much water flow is south west of there in the Colorado River. Here is a video from my spring break trip if you want to visually see Powell Lake – http://youtu.be/-xpiVZ_-6F8 !
After Powell Lake, the water flows southwest through the Grand Canyon, in Arizona. My friends and I hiked down to the bottom of the Grand Canyon where the Colorado River flows. Here is a little video of that if you want to see how big the river is – http://youtu.be/WhDvXf2YyAQ . It’s so wide and forceful even so far south of its source! Also, you can see that it looks pretty green. This is because the copper in the rock (which makes the grand canyon look red) oxidizes when it’s in the water.
After the Grand Canyon, the river flows north (a concept that I still find very cool) to southern Nevada to Lake Mead. In maximum water capacity, the reservoir at Lake Mead is the largest reservoir in all the United States. The Lake Mead Reservoir is formed by the Hoover Dam – which was built in the 1930s.
I like learning about the journey that the water of such a large river goes through. It’s so awesome to realize that one river can provide so many people with water – and it scares me that the projected 2026 is approaching so soon.
Both of you bring up a really good point about the availability of water and the priority of who will be able to use said water. When I was reading the articles from this week I thought about the changes in water reaching the LA area, how it will decrease, and how the city will gain the water it needs to survive. LA has already stretched far beyond the city limits to gain water (Owen’s Valley) and have done a lot of political actions to gain water rights. The one thing I thought the most about was the Pueblo Right. This law and court rulings found that LA was ownership of the water in the LA River and the surrounding waters that supplied the river. With a decrease in runoff, will the Pueblo Right still stand as it does now? Or will the welfare of the people in areas outside the city be considered more and have the Pueblo Right reversed so more people have rights to the water?
Although climate scientists have pointed out major detriments that climate change will cause in the future, not enough is being done to stop it. Many Americans are still unsure whether or not this phenomenon even exists, and even more believe that humans are not causing the warming of the earth. Instead of making the safe decisions and using the precautionary principle in terms of climate change, government officials seem to be waiting for the first disaster to hit the United States. Will debilitating droughts cause them to spring into action a little quicker? Destructive sea level rise? These disasters are already happening in countries in the global south, but the threat of lives lost in other countries doesn’t seem to have a great effect on the decisions our country’s leaders make. Hopefully the U.S. can make a responsible choice in regards to climate change at the Rio+20 Conference!
The problem with temporal estimations is that they always change when we change our behavior to reflect the projections. For instance, if experts tell us we have another 14 years to figure something out, we may take gradual measures that extend the countdown to disaster. We may improve efficiency, better develop renewable energy technology, stop building dams, etc. While these remedial actions are good, they may increase uncertainty regarding negative anthropogenic effects on the environment. For instance, skeptics may argue that human ingenuity will always be able to solve our environmental problems, and we can act irresponsibly until the environment is very degraded. At that point, technology and problem-solving steps in and saves the day. I think this mentality is prevalent amongst the American populace and that we should develop better education-building programs (either via PSAs or policy) to promote more thorough understanding (of our impacts on the environment) at all levels of society.
I agree a lot of people continue to doubt climate change is even true but I think the problem goes beyond that; many of those who do acknowledge the legitimacy of climate change still doubt it will have a significant impact on the way they live. If more people knew that we are facing a future where not only will there be more severe and frequent weather events but also a lack of accessibility to potable water they might care more. Maybe people think they might somehow dodge hurricanes, cool down during heat waves and run away from floods. I guess natural disasters don’t scare us because People still live in Florida and they know the hurricanes are coming, we still live in California and we know earthquakes happen and people know about climate change and they do nothing about it. But, can people really ignore the fact that their children or grandchildren will someday face not having enough water to drink. Like Addie said, not enough is being done today to prevent the catastrophes of the near future. More people need to be aware of the indirect and direct ways in which climate change will impact our way of life.
While scientists can always speculate how long non renewable resources will last, there are just so many variables to take into account that I usually take their estimates with a grain of salt. In particular there are many substances that interact with the hydrologic cycle that are still under investigation, such as Black Carbon or Aerosol concentration, that we still aren’t exactly sure what effect they will have. Aerosols are found to reduce precipitation downstream from the pollution source, and also to reduce the snow particle rime growth resulting in lower snow water equivalent for a flake of snow. Black Carbon is a common aerosol found in the atmosphere that snows down onto our icepacks. Since it is black it has the potential to decrease surface albedo thus increasing its ability to absorb solar radiation speeding up the melting process. With all these potential variables, I wonder how differently our water crisis will play out than expected.
I couldn’t agree more with Addie on this one. The impacts of global climate change are being taken far too lightly. The changes in seasonal runoff that will be caused due to increased temperatures from global warming are a prime example of this. The main problem in my opinion is the delayed impacts of problems of this nature. As Alex mentions in her post, studies have claimed that we will not have problems with the Colorado River until the year 2026. This gives people a false sense of comfort and causes them to put off taking any sort of preventative action. Unfortunately, when it comes to environmental problems in our society, people only seem to take action when disaster has already struck. It’s time that people wake up and smell carbon dioxide. 2026 is fast approaching and this problem is staring at us right in the face. The Colorado River is a snowmelt-dominated river that will experience seasonal runoff patterns if global warming continues on its course. Since the water from the Colorado River is so critical to the Western United states there are going to be major problems if nothing is done. Too many people are living in a false reality. We have already seen some of the devastating impacts of global warming and some of the even more threatening ones are approaching fast. More aggressive measures need to be taken to curb green house gas emissions in order to mitigate global warming and its effects. I would also recommend that we increase the reservoir capacity of the Colorado River to help deal with the changes in seasonal runoff that are almost inevitable at this point.
I agree with what most people are contributing in the sense that not enough if being done to mitigate effects impending climate change will have on our water source in LA. However, please outside the scope our your life. Our water needs in LA are starving the rest of the midwest and northern CA of their needs as well. We are not the only ones on the west coast here. GHG emission will continue to rise for another 10-12 years, even after we have completely stopped all emissions. That being said, there will be an additional 10 years of changes in the hydrological cycle and water resources for LA. Which, by the time we do actually stop emitting them, will take us way past 2026. By that time, in my opinion, it would be wise of most people that live in this region to leave an move somewhere else, where water is more plentiful in relation to their population. It is hard to say, because can you really imagine LA empty of people? I can’t. But I know, that if our population in this city is to continue to rise, we will not only see rises in food and oil price, but a significant toll on our per Capita water supply on not only Angelinos, but on the areas we are taking water from to feed our unquenchable thirst for other people’s water.
Overall, with the changes to be seen in our water supply, instead of starving outside ecosystems and populations from their domestic water, us Angelinos need to find a way to either leave and move out of the city that is doomed to fail, or wrap our heads around the idea of making treated water potable.
Food for though,
Sherwood Egbert
Excellent blog Alex, the Colorado River is a fantastic resource both in its physical beauty and the weight of life that it carries on its shoulders. I too recognize the issues inherent with climate change, but what should we do about it? I feel it is really easy to say more must be done, but what can be done that would really get the results we all want? We live in a, for the most part, democratic society and inherent with that is an atmosphere of conversation and debate. The process of discussing these issues will always take long and the “solutions” will always be ineffective compromises. Even if we somehow could get beyond simply our country’s decision making processes and stop all greenhouse gases immediately, what will that mean for us? That would require a complete shift away from 83% of our energy sources in an instant. The catastrophe that would cause would have worldwide repercussions. Sherwood brings up an excellent point that the main issue is the extremely high demand being imposed on the resource. However, who will move? How can we convince people to leave their homes for the sake of the environment or future generations? Even if we can get their sentiment, each person will ask “Why me and not them?” People need an incentive to move. If prices for water reflected their true cost and scarcity, they would be much higher in this region where it is limited, and people who can’t afford it will have an incentive to move to a place where they can. This is the only type of solution I have ever seen really work, it doesn’t rely on our agonizingly slow political system to make people do things through law, and it doesn’t rely on convincing people to act against their own interest. Incentives allow people to act in ways that best suit their needs without force or guilt.
This post really puts it into perspective the kinds of climate change-related pressures LA will face in the future in terms of reduced water availability. Being that LA is not self-sufficient in providing water to its citizens and that it has pretty much tapped all the nearby water resources (and even contaminated some beyond use), it greatly increases the need for improved methods of conservation. For example, in the future, we will have a greater need for improved technologies to recapture water. There are several rivers in the Greater Los Angeles area that empty into the ocean, and if those waters were somehow able to be recaptured and stored, it would serve as a way to increase the overall water supply without having to deal with the political backlash of attempting tap into yet another state’s water supply, or diverting any more water from Northern California. Improved water recapture methods would also eliminate the possibility of another Mono/Owens lake scenario from arising, as you not be stripping a water-dependent environment of its natural water supply. It may also be necessary in the future to increase efforts to clean up contaminated groundwater sources by either designating proper capture zones and pumping water into the ground to flush out the pollutants or by pumping water out of the ground and into treatment facilities. I was recently fortunate enough to tour the Burbank Operable Unit plant and learned that this is one of the places in the region where groundwater is treated to remove volatile organic contaminants such as trichloroethylene (TCE) and tetrachloroethylene (PCE) before it is put into the distribution system. It was very interesting to see the different treatment technologies that are currently being implemented, and the BOU is unique in that it the system is completely closed circuit, meaning that all of the water is recycled and all pollutants are collected into holding tanks and then properly disposed of. In other words, no pollutants are released into the environment, and the site manager was very adamant about stressing that they employ the best available technologies and try to be as “green” as they can. Hopefully in the future, this form of treatment will become more popular among other treatment facilities as our demand for water increases.