(NaturalNews) The historic California drought of the past few years is the worst one that has occurred in the last 500 years, according to a recent study published in the journal Nature.

After the announcement by California state officials that they had found no snow in the Sierra Nevada mountains for the first time in the 75 years since snowfall records began, a research team conducted a study aimed at finding out more about the region's long-term snowfall history.

By studying the thickness of rings in core samples taken from blue oak trees growing in the mountains, the researchers were able to accurately measure the winter rainfall records during past centuries.

Their findings came as a surprise. It was already known that the current drought cycle had broken records, but no one suspected that so much time had passed since the last dry period of this magnitude.

The four-year drought has forced the state to begin issuing mandatory water cuts in many areas. Some municipalities have been ordered to cut their water usage by as much as 35 percent as reservoirs and groundwater supplies are being drained without being replenished.

The annual snowpack melt supplies up to 30 percent of California's water supply. In the past few years, however, the amount of accumulated snow has been so diminished that reservoirs, lakes, rivers and other bodies of water fed by the runoff are nearing record low levels.

"Astonishing" results

Valerie Trouet, associate professor at the University of Arizona and senior author of the study, said:

The results were astonishing. We knew it was an all-time low over a historical period, but to see this as a low for the last 500 years, we didn't expect that. There's very little doubt about it.

The implications are enormous, not only for the state's environment and its wildlife, but also for the millions of people who live in California and depend on the water for their livelihood and basic survival.

Ecological collapse

The effects of the drought have triggered what can only be described as an ecological collapse. Dramatic evidence of this is apparent when one considers the fact that this year's wildfire season is the second-worst one in the past decade.

This year, there have already been around 1,000 more wildfires than there were last year, and firefighters are currently battling two fires that have destroyed more than 1,000 buildings in the past few days.

Wildfires and water restrictions affecting the human population are only part of the picture. The drought is also threatening much of California's wildlife. For example, federal and state officials have resorted to transporting salmon and other fish species to other parts of the state due to concerns that they will die off during their annual migration to the Pacific Ocean if they try to navigate rivers and streams that have completely dried up in places or are at dangerously low levels.

Things will only get worse

The truly frightening aspect of all of this is the fact that the experts are predicting that the situation will only continue to worsen in the coming years. The natural cycles, combined with what is called "anthropogenic (human-caused) warming", could lead to a 30-year megadrought.

Although many climate change skeptics would argue that there is no significant environmental effect from greenhouse gas emissions, the fact remains that something is causing the state of California to increasingly approach becoming an uninhabitable desert wasteland.

There is no arguing the fact that the demand by humans - who want it for everything from growing crops to filling swimming pools - does have a significant depleting effect on the natural water supplies of the region.

Sources include:

WashingtonPost.com

NYTimes.com