The Soft Path for Water

There are two primary ways of meeting water-related needs, or more poetically, two paths. One path -- the "hard" path -- relies almost exclusively on centralized infrastructure and decision making: dams and reservoirs, pipelines and treatment plants, water departments and agencies. It delivers water, mostly of potable quality, and takes away wastewater. The second path -- the "soft" path -- may also rely on centralized infrastructure, but complements it with extensive investment in decentralized facilities, efficient technologies, and human capital.1 It strives to improve the overall productivity of water use rather than seek endless sources of new supply. It delivers diverse water services matched to the users' needs and works with water users at local and community scales. This chapter tells the tale of these paths up to the present. Decisions made today, and actions of future generations, will write the conclusion of the story

Global Water Issues and Challenges for the New Century: Meeting Basic Human and Ecological Needs [abstract]

5 pages (includes 3 pages listing the Contributed Papers Session Schedule)

Global Water Issues and Challenges for the New Century: Meeting Basic Human and Ecological Needs [abstract]

5 pages (includes 3 pages listing the Contributed Papers Session Schedule)

Assessing the costs of adapting to sea-level rise: a case study of San Francisco Bay

Atmospheric concentrations of carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), tropospheric ozone (O3), chlorofluorocarbons (CFCs), and other trace gases are growing due to human activities. These trace gases are transparent to incoming solar radiation and trap outgoing infrared (heat) radiation, acting like a blanket to warm the Earth. Without any of these gases in the atmosphere, the surface of the Earth would be about 35 C (70 F) colder than at present, and life, if any could exist, would be quite different. This natural greenhouse effect is being intensified by human activities that accelerate the emission of these trace gases, such as the combustion of fossil fuels and deforestation. One of the direct consequences of climatic changes will be a rise in sea level due to the melting of land ice and the expansion of the upper layers of the ocean as they warm. This study presents a method for assessing the costs to society of protecting against an increase in sea level, and applies this method to the San Francisco Bay area -- a region of great ecological diversity, economic importance, and vulnerability. Hydrodynamic effects around the margin of San Francisco Bay are evaluated, structural options for protecting property are identified and chosen for threatened areas, and estimates of costs of protection are determined. For the purposes of this study, a one-meter sea-level rise was assumed, and all development below the future 100-year high tide elevation in San Francisco Bay was considered to be at risk. The types of shoreline protection proposed include constructing new levees and seawalls, raising existing levees and bulkheads, raising buildings, freeways and railroads where necessary, and replenishing beaches. The costs described here are not the total costs of protection -- for example, no estimates are available for evaluating costs of protecting natural ecosystems. Other 3 costs left out are described in detail in the text

Climate Change and the Integrity of Science

We are deeply disturbed by the recent escalation of political assaults on scientists in general and on climate scientists in particular. All citizens should understand some basic scientific facts. There is always some uncertainty associated with scientific conclusions; science never absolutely proves anything. When someone says that society should wait until scientists are absolutely certain before taking any action, it is the same as saying society should never take action. For a problem as potentially catastrophic as climate change, taking no action poses a dangerous risk for our planet

Climate Change and the Integrity of Science

We are deeply disturbed by the recent escalation of political assaults on scientists in general and on climate scientists in particular. All citizens should understand some basic scientific facts. There is always some uncertainty associated with scientific conclusions; science never absolutely proves anything. When someone says that society should wait until scientists are absolutely certain before taking any action, it is the same as saying society should never take action. For a problem as potentially catastrophic as climate change, taking no action poses a dangerous risk for our planet. Scientific conclusions derive from an understanding of basic laws supported by laboratory experiments, observations of nature, and mathematical and computer modeling. Like all human beings, scientists make mistakes, but the scientific process is designed to find and correct them. This process is inherently adversarial—scientists build reputations and gain recognition not only for supporting conventional wisdom, but even more so for demonstrating that the scientific consensus is wrong and that there is a better explanation. That’s what Galileo, Pasteur, Darwin, and Einstein did. But when some conclusions have been thoroughly and deeply tested, questioned, and examined, they gain the status of “well-established theories” and are often spoken of as “facts.” We urge our policy-makers and the public to move forward immediately to address the causes of climate change, including the unrestrained burning of fossil fuels. We also call for an end to McCarthy-like threats of criminal prosecution against our colleagues based on innuendo and guilt by association, the harassment of scientists by politicians seeking distractions to avoid taking action, and the outright lies being spread about them. Society has two choices: We can ignore the science and hide our heads in the sand and hope we are lucky, or we can act in the public interest to reduce the threat of global climate change quickly and substantively. The good news is that smart and effective actions are possible. But delay must not be an option