Serving Huntington Beach, Costa Mesa and surrounding communities
Greenhouse Effect. Click for larger image
Global warming and its projected impact upon California livened up a recent Water Advisory Committee of Orange County (WACO) meeting. Dan Cayan, a climate researcher from UCSD's Scripps Institution of Oceanography, presented at the Sept. 8 meeting a range of likely scenarios Californians may expect as emissions from fossil fuels and other greenhouse gases continue to rise.
Cayan's research shows that human activity, like burning fossil fuels and clearing forests, especially during the last fifty years, has significantly affected Earth's atmosphere. The gases released, like carbon dioxide (CO2), traps heat that would otherwise escape into space, warming Earth's surface to a greater degree than if those “greenhouse” gasses weren't present in such high amounts. These emissions remain “trapped” in the atmosphere for many years. CO2, for example, lasts about 100 years.
Of course the WACO meeting brought out a few climate-change skeptics who questioned the research data or criticized with such red-herrings as why the planet Mars' rate of warming matched Earth's. Cayan reassured the skeptics that the data from numerous and varied sources, like tree rings, ice cores and sediment, that cross-check each other, all demonstrate all that there is an unprecedented rate of global warming.
“In the last two decades we've seen the warmest temperatures in thousands of years, greenhouse gasses have increased remarkably and climate models predict without any evidence to the contrary that climate will warm considerably” Cayan said. He added that greenhouse gasses, in other words, human activity, conclusively contribute to warming. “What we see already is a fingerprint of warming.”
Globally, temperatures have risen about 1° F during the past 100 years. And locally, California has had warmer winter and spring temperatures and lower snow levels. Snowpack has also been melting earlier and spring flowers are blooming one to two weeks earlier than previously, due to the briefer cool season. [the 9th slide might work here “very broad winter and spring warming 1950-97]
To give the attendees an idea of what the future may hold for Orange County weather conditions, Cayan presented three global emissions calculations which were selected from a set of scenarios developed by the Inter-governmental Panel on Climate Change's (IPCC) Special Report on Emissions Scenarios, based on varying assumptions about population growth and economic development.
The three scenarios present Earth at varying degrees of potential emission levels. At the lowest level where there is a rapid shift in fossil fuel intensive industries and a move toward green technology: CO2 levels will still have doubled from the pre-industrial age and climate rises by 3° to 5.5° F during the 21st century.
At the medium warming range, in a model where technological and economic growth is uneven, CO2 concentration triples and temperatures raise 5.5° to 8° F.
At the highest range, the “business-as-usual” scenario, with our present-day fossil-fuel intensive economic growth with green technologies not being introduced until the end of the century, CO2 more than triples and average temperatures rise from 8° to 10.5° F.
With this worst-case, “as-is” scenario, California will see a reduction in its Sierra Nevada snow pack by up to 90 percent. Californians can depend on severe summer water shortages and little winter skiing if nothing is done to curb greenhouse gas emissions.
Even at the medium scenario, late spring water flow is reduced by 30 percent; which would hit agricultural areas very hard, especially as warmer temperatures increase a crops' water needs.
Another risk, besides less snow pack, that threatens California's already demanding water supply would be the rising sea levels that global warming will cause as water presently locked up in ice in polar and mountain regions melt and increase the oceans' water volume. Seawater intrusion into ground water aquifers, estuaries and wetlands would threaten the quality and reliability of the major fresh water supply that is pumped from the Sacramento/San Joaquin River Delta.
Even at the lowest emission level scenario, snow pack losses will still be half as large as the warmest scenario. The best-case scenario presented leaves California with 30 to 60 percent less snow pack in the next century.
A warmer climate will, and is already, raising the elevations where snow falls and remains solid. AS precipitation falls as rain instead of snow California can expect more rain, earlier run-off, earlier spring melt, more severe floods, and eventually emptier reservoirs. Further impacting scarce supplies is the continually growing demand for water from a growing population of California and the continually thirstier agricultural industry which supports this growth.
Recently California enacted a landmark global warming measure. Gov. Arnold Schwarzenegger signed the measure which cuts greenhouse gas emissions in the state by up to 25 percent by 2020. This measure is seen as one of the country's most ambitious effort so far to curb global warming trends.
Cayan acknowledged that this legislation puts California on track toward the lower end of the emission projections, but he said it is important to keep in mind that reducing emissions only until 2020 will be inadequate. The projections he has are for 100 years, and fourteen years of lower emissions will be insufficient.
Huntington Beach council members Debbie Cook and Keith Bohr are in favor of curbing emissions. Bohr says the new legislation is going in the right direction, as long as business interests are protected too.
Cook says that people need to change consumption behavior at a personal level. Cook, for instance, lives in a solar energy home and drives a fuel efficient car. She says we need to use water more efficiently and we need to deal with global warming effects holistically.
Since climate change will reduce the state's snow pack storage, Cook says “California needs to deal with the storage issue and reports like these are opportunities to get moving on projects.”
Cayan agrees. He says it is a good thing to store water. He thinks new ways of manipulating groundwater storage plus additional means of conveyance are necessary. “Conveyance is as important as storage,” he added.
Costa Mesa Council Member Katrina Foley agrees with Cook that we all need to do our part as individuals, plus we need to change corporate culture. She said, “I drive a hybrid and it would be great if car manufactures would offer more hybrid models.”
She also suggested that locally government can play a role in green building, yet she admitted that her city is a little behind.
Corporate culture, especially the energy industry, has created some skepticism in the global warming concept; despite the scientific evidence. Cayan explained that there really are very few scientists who are truly skeptical about the problem of global warming, but feels that because the press feels obligated to show two sides of a story, often extra weight is given to an element (the anti-global warming position) that is scientifically not very credible.
Some climate experts who long suspected that the sun itself, with its changes in luminosity could be at fault for global warming have discovered that the sun's energy output played little or no role in climate change, as scientists reported recently in the scientific journal Nature. The study of 1,000 years of variations in solar activity finds little or no direct effect on Earth's climate change.
But scientists are saying that air pollution is reducing precipitation as well as contributing to global warming. Bits of air pollution as small as a thousandth of a hair's width appear to be reducing rain and snowfall in the Sierra, the Cascades and the Rockies.
Three years ago Israeli cloud physicist Daniel Rosenfeld saw clues in data from a NASA satellite that tiny airborne grime released by everything from diesel trucks to cattle was affecting clouds and precipitation downwind of cities. Other scientists worldwide are finding the same phenomenon. Scientists have detected these tiny bits of pollution in specially equipped planes flying over the San Francisco Bay and other urban areas. Those bits of pollution become seeds for cloud droplets that are so small that they don't readily fall as rain or freeze into snowflakes.
WACO meets monthly, with participants ranging from water district board members, officials and others involved in water resources, in the Orange County Sanitation District's (OCSD) boardroom.
