Climate change involves natural and man-made changes to weather patterns that occur over millions of years or over decades.
In the past 150 years, human industrial activity has accelerated the rate of change in the climate due to the increase in greenhouse gases (carbon dioxide, methane, and nitrous oxide). Scientific studies describing this climate change continue to be produced and its expected impacts continue to be assessed.
Throughout the state, there are more than 100 active faults that have produced earthquakes resulting in widespread damage and deaths. In Southern California alone, since 1933, there have been 23 significant quakes of magnitude 5.9 or greater. The San Andreas Fault, the major fault line running through California, is expected to be the source for a major earthquake. It was the source for the earthquake that leveled San Francisco in 1906.
Water infrastructure is vulnerable to earthquakes:
Devastating floods are almost annual occurrences in the West and in California. With the anticipated sea level rise and other impacts of a changing climate, particularly heavy winter rains, flood management is increasingly critical in California. Compounding the issue are man-made flood hazards such as levee stability and stormwater runoff.
Hydraulic fracturing, commonly known as fracking, injects high pressure volumes of water, sand and chemicals into existing wells to unlock natural gas and oil. The technique essentially fractures the rock to get to the otherwise unreachable deposits.
Despite droughts, the recession and natural disasters, California’s urban population continues to grow.
This population growth means increasing demand for water by urban areas—home to most of California’s population [see also Agricultural Conservation]. As of 2012, seven of the most populated urbanized areas in the United States are in California.
California would not exist as it does today were it not for the extensive system of levees, weirs and flood bypasses that have been built through the years, particularly in the Sacramento-San Joaquin Delta.