a cautious, and as it turned out, pro- phetic warning to those in attendance. “Gentlemen, you are piling up a heritage of confl ict and litigation over water rights, for there is not suffi cient water to supply the land,” said Powell, whose words were not well-received. Since Powell’s speech, a remark-
able amount of innovation, investment, technical achievement and can-do spirit have enabled the West to house large cities and farms because of the ability to provide water. Nonetheless, the stark reminder of the region’s weather extremes constantly reminds people that water is not some-
thing to be taken for granted. When Powell spoke, the term climate change was unheard of. Today, the president of the United States says the science is clear and the time for action is now.
“The 12 warmest years in recorded history have all come in the last 15 years,” President Barack Obama said in a June 25 speech at Georgetown University. “Last year, temperatures in
some areas of the ocean reached record highs, and ice in the Arctic shrank to its smallest size on record – faster than most models had predicted it would. These are facts.”
Watch President Obama speak about climate change
Climate is generally defi ned as “average weather” and is usually described in terms of averages and measures of variability in temperature, precipitation and wind over a period of time, according to the Cal/EPA report. Global observations provide “unequivo- cal evidence that the climate is warming,” with the annual average temperatures in California up by about 1.5 degrees Fahrenheit since
1895, the report says, noting that “parts of the Central Valley and Southern California have experienced the great- est warming.” Winters are marked by a decreasing “winter chill” in fruit-growing regions of the state, an important development given that many fruit trees require a certain number of hours below a tem- perature threshold to produce fl owers and fruit, the report says. At a larger
level, the altitude in the atmosphere at which temperatures drop below freezing has risen by about 500 feet the last 20 years, an indication of warming condi- tions at higher elevations.
Impacts on coastal systems “are among the most costly and most certain consequences of a warming climate,” according to Coastal Impacts, Adapta- tion, and Vulnerabilities, a technical report prepared for the 2013 National Climate Assessment. The costs of esti- mated sea level rise were evaluated for several communities, including Ocean Beach in San Francisco, Venice Beach in Los Angeles and Torrey Pines in San Diego. Simulated conditions involving storm surge indicated that a 100-year storm would result in “particularly high losses,” under current conditions, with losses increasing by 2100. “Overall, losses to beachfront recreation as well as upland property due to shoreline retreat and increased storm damage along those stretches of the California Coast amount to an estimated $100 billion over the next century,” the report says.
Addressing the effects of climate change on California as a primer for
To help protect against sea level rise, one-third of the shoreline of Southern California (including Ventura, Los Angeles, Orange and San Diego Counties) has now been armored. This photo shows the shoreline in 2010 in Encinitas, in northern San Diego County.
Copyright (C) 2002-2013 Kenneth & Gabrielle Adelman, California Coastal Records Project, www.Californiacoastline.org
8 Western Water
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