On Wednesday Dr. Peter Gleick of the Pacific Institute gave a talk on “The Present and Future of Water”. His presentation was excellent, with slides picturing data to substantiate the points he made. Without his slides, I pulled material from the internet to illustrate some points he made.
For example, Gleick showed atmospheric carbon dioxide graph through time, similar to the one above from Wikipedia. Looking at the graph above, carbon dioxide in the earth’s atmosphere has not exceeded 300 parts per million for 400,000 years, until 200 years ago when the industrial revolution started and we’ve burned fossil fuels to generate energy, dumping carbon dioxide into the atmosphere. This period includes several cycles of ice ages and the warming periods in between. The atmospheric carbon dioxide level is now at 400 ppm. Note: I believe that Gleick showed the past 800,000 year, but I found only this graph with 400,000 years.
Gleick covered four areas in his talk: 1) the present state of water in California, 2) climate change, 3) water and conflict, and 4) solutions.
Gleick started with the present state of water in California, where we are in the third year of a drought. Last week California voters passed a $7.5B bond measure on water. With interest payments, the bonds will cost $14B. The Pacific Institute’s assessment is that the bond measure is a down payment, that more will be required.
Eighty percent of California’s water is used by agriculture; the remaining 20% is used by urban and suburban users. Residential users consume 64% of that 20%, with half used outside the home. Californians use more water than is supplied by rain, so each year we pump 1-1.5 million acre-feet of groundwater more than is replaced. Groundwater supplies are finite, so this sustained, massive overdraft is not sustainable. This fall California passed our first laws to measure and manage groundwater, but implementation will takes years.
Because of the drought, 10% of the agriculture land is fallow this year. Fifteen percent of California’s electricity is normally generated from dams. However, with less water available because of the drought, only 7-8% of our power will come from hydroelectric this year. To replace the missing hydroelectric power, we’ll burn more natural gas, adding more CO2 to the atmosphere.
For climate change, Gleick made several points.
- As discussed above, man has dramatically increased atmospheric carbon dioxide during the industrial revolution, as we burn fossil fuels to generate energy to do work.
- The earth’s temperature rises and falls as atmospheric carbon dioxide rises and falls. From the US National Oceanic and Atmospheric Administration (NOAA) “One of the most remarkable aspects of the paleoclimate record is the strong correspondence between temperature and the concentration of carbon dioxide in the atmosphere observed during the glacial cycles of the past several hundred thousand years.” From the NOAA graph below, notice that the blue temperature rises and falls as the red atmospheric carbon dioxide rises and falls.
- The US temperature has been rising since 1895, consistent with the atmospheric carbon dioxide level.
- The snowpack and the moisture content of the snowpack is shrinking in the western US as the temperature rises.
- In the western US, our rain comes with storms, and storms come when an atmospheric river is pointed at California. For example, here’s an account of a past storm from weather.com, “A long plume of moisture is headed into California as I write this on Friday December 17 and threatens to bring up to a foot of rain on foothills and possibly up to 15 feet of snow at high altitudes by the middle of next week. … A generic name for this plume of moisture is “atmospheric river”, as shown on the satellite image below from Friday afternoon . It’s a “fire hose” of atmospheric moisture.
- One cause of California’s drought is a high pressure ridge that has diverted the atmospheric river away from California.
- This high pressure ridge is more likely with the current buildup of greenhouse gases, according to a Stanford study.
- Natural catastrophes such as hurricanes are rising. Hurricanes get their energy from warm ocean water, and the earth’s oceans have gotten warmer. Oceans are rising as glaciers melt. Hurricane Sandy caused much more destructive flooding when high winds struck New York during a high tide. As hurricanes increase and the oceans rise, we can expect more of the same.
Gleick showed that world water conflicts have been growing since the 1980s. Water supplies have not increased, while population has.
He discussed Syria as an example. The Euphrates River starts in Turkey, flows through Syria, and then to Iraq. The amount of Euphrates water flowing into Syria has been dropping, while the population of Syria has grown from 3 million in 1950 to 22 million people today. Syria has had a deep drought since 2009, ruining farming and causing widespread migration from rural areas to cities. Areas receiving the most immigrants have experienced higher conflict in Syria’s civil war.
Gleick discussed California, mentioning his analysis of proposition 1, the recently passed $7.5B water bond. $2.7B is set aside for water storage, but Gleick says that traditional solutions such as building new reservoirs are “tapped out”. He showed storage capacity over time. California has 40 million acre-feet of water storage. Most dams were built between 1920 and 1980, with only minor additions since then. The best sites have been built so the marginal benefit of new reservoirs is small. Public oversight of the commission responsible for spending $2.7B is critical. “Only one percent of bond funds will be spent on conservation and efficiency”, and these are the only items that will “provide immediate relief from the drought”. In other words, water wars of the western US aren’t over.
Gleick discussed solutions such as increasing supply and reducing demand. As for supply, we already use all the rainwater we have, and we overdraft groundwater at an unsustainable level. To increase supply further, we could treat wastewater, use storm water, and desalinate water (very expensive). To reduce demand, measures such as carrying shower water outside to water plants or not washing cars are temporary. Replacing lawns with drought-tolerant plants and flushing toilets with non-potable water are recurring solutions that will save water every year.
Water is an underpriced utility — we pay less for water than other utilities. As a result, people have little economic incentive to conserve water. Our water bill doesn’t pay for large infrastructure such as building new dams or replacing aging pipes and aqueducts. For example, at some point the pipes bringing Hetch Hetchy water from the Sierras to San Francisco and the peninsula will have to be replaced, and we’ll have to find funds.
California’s water institutions and management aren’t set up so that we use water efficiently. California allocates water based on historic water rights, and not the efficient use of water to boost the productivity of California today and in the future. Our new laws allow years to measure, understand, and manage pumping groundwater.
There is no silver bullet for water — no one of these potential solutions will solve California’s water problems.