/* Written 5:20 pm Aug 30, 1991 by pacinst in cdp:en.climate */
/* ---------- "Executive Summary of Report LONG" ---------- */
On August 1st, the Pacific Institute release a report on the impacts of the California Drought. By popular request, here is an abbreviated version of the published Executive Summary. I have included only the more critical sections, but in the interests of keeping it short, I have deleted several sections. All sections HEADINGS were left in to let you know what it contains; those of you interested in more detail can either order the whole report, or contact me for more information. The full report is 66 pages long.
Peter Gleick, Director, Global Environment Program
THE SOCIETAL AND ENVIRONMENTAL COSTS OF THE CONTINUING CALIFORNIA DROUGHT:
A Report from the Pacific Institute for Studies in Development, Environment, and Security, 1681 Shattuck Avenue, Suite H, Berkeley, California. 415 843-9550.
["pacinst" on EcoNet]
EXECUTIVE SUMMARY
Since 1987, the State of California has been in the grip of a severe drought. Water availability throughout the State has been far lower than normal for each of the last five years when measured in any of a variety of ways: total precipitation, runoff, ground-water overdraft, or reservoir storage. The current drought is comparable in severity to the drought of the late 1920s and early 1930s, considered to be the worst drought on record, and there is no guarantee that next year will be any wetter. The California Department of Water Resources has classified four of the last five years as "critically dry", while the fifth was classified as "dry".
Based on the information collected for this report, we believe that the greatest impacts are currently falling on the environment, and that, moreover, many of the ecological effects may be irreversible. In addition, California will see substantial economic costs, totaling roughly $3 billion, as a result of decreased hydroelectric potential. Limited portions of the agricultural sector are also bearing heavy costs, although the effect on California's overall farm income will be relatively small. While urban areas have suffered shortages, they have been manageable in most cases and have not caused major economic dislocations. The additional rainfall that the State received in March of this year helped to avert much more serious impacts in the municipal and industrial sectors, but only modestly improved the condition of ecosystems and the water supply for agriculture.
The drought is not over. Without doubt, another dry year would result in much more severe situation than California has experienced thus far. Reservoir reserves have been drawn down to extremely low levels, some fisheries populations have been brought to the verge of extinction, if indeed they have not already been pushed over the edge, and ground-water reserves have been severely depleted in many agricultural regions.
Presented below is a summary of what we currently know about the impacts of the drought.
Summary of Impacts
Natural Ecosystems
Human activities have made natural ecosystems more vulnerable to droughts than they would otherwise be, and, consequently, the current drought has had severe impacts on a wide range of California's ecological resources. Given the poor condition of the most threatened species, the greatest concern is that some species may not be able to recover once the drought is over. Among the effects observed as of July 1991 are:
The coho and chinook salmon catch off the coast of California has declined from a record 14.8 million pounds in 1988 (reflecting the success of the year class raised in the wet year of 1986) to only 4.4 million pounds in 1990. The current estimate for 1991 is 2.5 million pounds.
The winter-run chinook salmon, already classified as a threatened species, has reached such low numbers that it is threatened with extinction.
The population of striped bass in the San Francisco Bay/Delta has been declining since the beginning of the current drought in 1987. In 1990, the index of larval abundance was the lowest ever recorded. While the decline of the striped bass may have many causes, the striped bass index shows a strong correlation with Delta outflow.
The herring fishery in Tomales Bay has been destroyed, at least temporarily, due to low freshwater inflows and consequent increases in salinity. It is possible that this herring population will not recover.
Waterfowl populations in California have been declining dramatically over the last decade for many reasons. The drought is exacerbating these losses by reducing the quantity and quality of wetlands habitat in the Central Valley.
Tree mortality has been extremely high in large areas of the Sierra Nevada. In some forest areas, 30 to 80 percent of the trees are dead or dying.
A wide range of endangered and threatened plant and animal species are directly threatened by low water conditions, including: nesting and wintering bald eagles in the Santa Ynez basin; the ten listed species of native annual and short-lived herbs; the threatened giant garter snake, which depends on seasonal and permanent sloughs and creeks; and almost all of the nine species of endangered butterflies, which are experiencing severe population declines because of drought-induced losses of host plants.
Agriculture
Undoubtedly, the drought has reduced California's agricultural income over what it might have been in 1990 and 1991, although it is has not been the disaster that some expected. Certain agricultural sectors and individual farmers have been hard hit by cutbacks in water deliveries. But we also find that the California agricultural community as a whole has experienced manageable losses, in part because the agricultural sector was in a strong financial position before the drought began and because it has been buffered by ground-water availability and the ability of farmers to alter planting patterns.
Until 1990, agricultural water deliveries were not affected by the drought, and no significant economic impacts were observed. In 1990, some water deliveries were reduced, but overall impacts were minimal. Strong demand for California farm products has kept both prices and revenue high. Gross cash receipts in 1990 reached an all-time high.
Greater agricultural impacts will occur in 1991, but it is too early to quantify these effects. A preliminary estimate by the California Department of Water Resources puts direct losses at roughly $400 million in cash receipts out of an estimated $18 billion total. In addition to these direct losses, there could be substantial indirect costs throughout the State.
The statewide averages hide local effects. Some agricultural communities have been hard hit, including the southern San Joaquin Valley, where ground-water supplies are scarce, and the Central Coast region, where there is extensive dryland agriculture and a high dependence on ground water and precipitation.
Ground-water storage in the San Joaquin Valley has declined dramatically since the onset of the drought, and will decline even more in 1991. Between 1987 and early 1991, ground-water levels in Tulare County had dropped by over 30 feet and 3.3 million acre-feet. In Madera County ground-water levels has dropped by over 25 feet and 1.4 million acre-feet. Should the drought persist, the decreased availability of ground water will have major impacts on the agricultural sector.
Livestock and Grazing [section not included here]
Energy
The drought in California has affected both the supply of and demand for energy. California is highly dependent on hydroelectricity production -- about one-third of all electricity produced in-state is hydro -- and the drought has greatly reduced hydroelectric generation. As a result, more fossil fuels have been purchased and burned by California utilities. Electricity used for ground-water pumping has also risen with the increased demand for ground water by the agricultural sector.
Because the cost of generating electricity with natural gas is higher than the cost of producing hydroelectricity, the drought has led to a direct increase in electricity costs to California ratepayers. We estimate that the first four years of the drought (1987 to 1990) cost California ratepayers an extra $2.4 billion.
Hydroelectricity production in 1991 will also be well below average, and the additional costs to ratepayers this year may exceed $500 million.
The burning of extra fossil fuels has also increased air pollution. We estimate that the added fossil fuel combustion has increased California's utility emissions of carbon dioxide, the principal gas responsible for the greenhouse effect, by over 25 percent from levels emitted during a normal water year.
Forestry and Fire
The five years of the drought have had an enormous impact on the forests of California. Trees have become highly susceptible to both disease and pest infestation. There has already been a significant die-back of trees throughout the State, particularly in the Sierra Nevada, while many more trees are sick or infested. In addition, dead and downed trees have created substantial amounts of dry fuel that greatly increases the risk of intense and destructive forest fires.
The California Department of Forestry estimates that 12 billion board feet of merchantable timber has been lost on State lands; over 5 billion of that in 1990 alone.
The U.S. Forest Service estimates that 10 percent of the trees in 18 National Forests have been killed by the drought and related insect infestations. On the approximately 6.5 million acres managed by the U.S. Forest Service for commercial lumber, 2.6 billion board feet of timber was killed by the drought in 1990. Estimates for August 1989 and August 1988 were each approximately 1 billion board feet.
Of the 2.6 billion board feet of dead trees in U.S. National Forests as of August 1990, the Forest Service estimates that only 1.6 billion will be salvaged -- about 800 million board feet each in 1990 and 1991.
The drought has led to greater expenditures for fire protection, fire control staffing, and operational expenses. State and Federal emergency expenditures for fire suppression and fighting exceeded $100 million in 1990. These expenditures are over and above the regular costs of maintaining fire-fighting equipment and personnel.
Recreation and Tourism [section not included here]
Municipal and Industrial Users [section not included here]
The Drought as an Analogue of Climate Change
Given the current concern over global warming, the question of whether this drought is a manifestation of "global climatic change" invariably arises. While the drought could be associated with larger scale changes in the climate, we are unlikely to know for several more years. Nevertheless, if the drought is merely an extreme of the current climate rather than a manifestation of anthropogenically induced climate change, it may still serve as an analogue of a future climate that is more severe than that of the present. The drought does not provide any information on the effects of increases in global and regional temperature, changes in climatic variability, the hydrologic effects of sea level rise, or a host of other issues. But it does illustrate the impacts of decreased precipitation and runoff, one possible change that might accompany global warming. More importantly, however, the drought is indicative of our society's ability to adapt to climatic variations and the vulnerability of California to long-term shifts in hydrology and water availability.
The impacts of the current drought suggest that the California economy can withstand five years of reduced water supply, but that we are running up against severe limits and facing difficult choices. Specifically, ground-water supplies and reservoir storage, which so far have buffered the impacts in the agricultural sector, have been heavily depleted and will be of limited value if the drought continues. Many threatened wildlife populations are so strained by five consecutive years of drought that their ability to recover is being questioned. If the drought were indicative of long-term changes in the State's water supply, it would imply fundamental changes in the State's economy and environment.
Although an imperfect analogue to global warming, the drought highlights the vulnerability of the economy and the environment of California to variations in climate. The worry, however, is that climatic changes would be even more extreme than the drought we are currently experiencing. Moreover, our response to the drought suggests that we will tend to discount the future and adopt the easiest responses first. On the positive side, the drought has forced California to re-analyze its water policies and has spurred an important debate about vulnerability, tradeoffs, and priorities. In this sense, the drought may provide the impetus to plan for and to adapt to global warming.
