California outlines program for responding to climate change; the underlying assumptions about climate change paint a bleak picture
Much of California’s response to climate change has focused on what the State can do to lessen its contribution to global warming. However, as noted in prior posts, many experts predict that no matter what California or anyone else does greater warming is all but inevitable; the only question is how much impact there will be and over what time period.
Thus, last year Governor Schwarzengger issued an Executive Order outlining a plan for adapting to this change (Executive Order S-13-08). One of the provisions in that order requires the state Department of Natural Resources (formerly the Resources Agency) to develop a state Climate Adaptation Strategy. What is interesting is not so much the strategy, but the scenarios used as part of the assessment.
The report based its predictions and conclusions on two separate scenarios. One of these scenarios (the A2 scenario) assumes a more competitive world that lacks cooperation in development and portrays a future in which economic growth is uneven, leading to a growing income gap between developed and developing parts of the world. The second scenario (B1) assumes a future that reflects a high level of environmental and social consciousness combined with global cooperation for sustainable development.
For California, these two scenarios result in a range of possibilities that are laid out in the report:
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A projected increase of 1.8 to 4.4 degrees Fahrenheit by 2050; this would amount to an increase of one to three times that which occurred over the entire 20th Century. Much of this increase, says the report, is already predetermined due to the existing amount of carbon in the atmosphere. By 2100 temperatures could increase from 3.6 to 9 degrees depending on what actions are taken currently.
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By mid-century, models suggest a decrease in statewide precipitation of 12 to 35%. The impact of this change is heightened by the likelihood that less of what does fall will be in the form of snow resulting in less runoff that can be stored for use in dry months.
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By the end of the century sea level could rise by up to 55 inches, and possibly even higher if there is substantial melting of the Greenland or West Antarctic ice sheets.
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What have been extreme temperatures events occurring once every 100 years may start to occur annually.