Human Activities Contribute to California\'s

¶ … Human Activities Contribute to California's Global Warming," research scientists at the Lawrence Livermore National Laboratory, the University of California and other research centers have recently concluded that temperatures in the state of California "have jumped...by more than 2.1 degrees Fahrenheit within the last eighty-five years" and that the most likely culprit for this increase is linked to human activities, such as emissions from automobiles, coal-burning power plants, home air conditioning units and pollution in the form of smog. Not surprisingly, it has been determined that this rise in temperature occurs in late winter and early spring, due to "large changes in atmospheric conditions in the northern Pacific" which result from greenhouse gas-induced warming via high levels of CO2.

According to Celine Bonfils of the Lawrence Livermore National Laboratory, "The trends in daily minimum and maximum temperatures over the last 50 and 85 years are inconsistent with current model-based estimates of natural internal climate variability (and) it's pretty clear that natural causes alone just can't cut it and external factors such as greenhouse gases and urbanization come into play." Clearly, the rise in temperatures throughout California are closely related to what Bonfils calls "external factors," such as coal-burning power plants, automobile emissions and similar man-made sources. One must take into account the fact that since the dawn of the Industrial Revolution in the United States during the middle years of the 19th century, sources which emit CO2 and other greenhouse gases have increased ten-fold as compared to when California was mostly an agricultural environment until the rise of industry and the development of industrial factories.

Phillip Duffy, a member of the Lawrence Livermore team and a professor at the University of California at Mercer, points out that current meteorological models which have been used for almost fifty years to determine changes in atmospheric temperatures, do not concur with what is now happening in California. "One possible reason," he says, "for this is that most models don't include factors such as irrigation which can influence regional climates," meaning that the increase in large-scale irrigation during the 20th century has not been accounted for in current meteorological models. Bonfils adds that researchers have found "empirical evidence that irrigation has a large cooling effect on local summer daytime temperatures but minimal effect on nighttime temperatures."