Though there are thousands of miles between California and Argentina, they do share at least two similar qualities. Relative location to the Pacific Ocean and relative location to the equator are essentially the same for both Argentina and California and these two qualities are enough to cause uncanny similarities in weather patterns, including one weather pattern both areas fall victim to: droughts.
A drought, caused by lack of water, can cause plants and animals to die, and in severe droughts, even human beings have been known to pass away from dehydration. Rain in the winter can be retained, frozen, in the mountains, which means rivers run full during the hot months of the year when water is most needed. Even rain in the spring and early summer help problems caused by drought because any water is better than none at all.
So where has the rain gone? There is a periodic (2 to 7 year) temperature cycle that has been known to cause droughts along the eastern half of the pacific ocean in the hot climate areas like California and Argentina. What causes this? El Nino or La Nina can cause a build up of air pressure over Tahiti and the western parts of the Pacific Ocean, causing a drop in pressure on the other side of the Pacific. Trade winds (caused by sunlight and the rotation of the earth), usually heading west can weaken because of this pressure change and possibly even reverse, heading east. Warm water in the Pacific Ocean spreads east and the rain follows causing droughts in the west pacific and rainfall in the east. When this cycle reverses itself periodically, the opposite occurs where California and Argentina, both hot weather climates relying on winds in the Pacific Ocean and the sea surface temperature to bring the rain succumb to drought conditions.
During a drought it's impossible to increase the flow of water in rivers or rainfall. All one can do is try to capture what water is available and stem unnecessary use and loss of water in rivers. California has responded by rationing and regulating water supplies, even as recently as earlier this year when California imposed new sanctions on the use of water in the Russian River.
Agriculture is affected by droughts drastically since a water reduction can lead to crop failures, adding turmoil in this time of global economic recession. Wildlife species of fish and waterfowl in the rivers of both California and Argentina can become endangered. Community use and recreational water activities become reduced and more heavily monitored as well as more expensive (with regulations come the necessity of purchasing permits for water use). In the summer months, especially in California, forest fires become more common as droughts become more severe. Since California is in its third year of a drought, hopefully the cycle is at least halfway over and we should start seeing more rainfall in the next few years. Argentina is also experiencing one of its worst droughts in recent history. Even drinking water is in short supply. With agriculture struggling, the rate of crop failures is high and the economy is hit hard.
With the increase in global warming, we can assume that the drought conditions during the peaks of the temperature fluctuation cycle will continue to become more and more drastic, making it a necessity to provide stores of drinking water for people worldwide. We'll need to do more than just rely on the goodwill of international charitable organizations.