- jaime gonzalez
- BBC World, Los Angeles, @bbc_gonzalez
image source, Getty
Huge fires devour miles of hectares of forest, farmers have to abandon their crops, suffering millions in losses, and the authorities are forced to reduce water consumption among the population given the constant decline in water reserves.
We are not describing an apocalyptic scenario that, according to scientists, could take place in many parts of our planet in the not so distant future as a result of climate change, but rather the situation currently being experienced in the southwestern United States .
The lack of precipitation has been severely occurring for three years in states such as California, Arizona and New Mexico, in what is the worst drought on record in the area for more than a century, when it obtained those detected.
The authorities and meteorologists are confident that after the end of the boreal summer the long-awaited rains that usually occur in the region in the autumn months and, in particular, winter, will arrive, although no one can guarantee that this will happen.
Is it possible that the drought will continue for the rest of the decade? And if the absence of precipitation goes further?
If we stick to one of the latest scientific investigations on this matter, the future does not look very promising and the region could experience a situation similar to that experienced 9 centuries ago, only now with a population of 50 million inhabitants to maintain.
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Given the decline in the reservoirs, water restrictions have been implemented in some areas.
The megadrought
Experts from Cornell University, the University of Arizona and the US Geological Institute published a study a few days ago indicating that the chances of a drought lasting at least a decade affecting the southwestern United States. have felt between 50% and 80% as a result of climate change.
The scientists go further and ensure that the probability that the region will register a «mega-drought» that will last for a period of more than 30 years has reached between 20% and 50%.
«A megadrought is one that lasts in time for more than three decades. It has to do with its duration and not so much with its severity,» Toby Ault, professor of atmospheric sciences at Cornell University, who explains to BBC Mundo led the aforementioned study.
«A mega-drought does not mean that it stops raining completely. It implies a significant reduction in rainfall over a long period of time,» says the expert.
According to Ault, from the paleoclimatic data available in the region -such as tree rings or lake sediments- it is known that «in the past there have been mega-droughts that have lasted three decades or even more.»
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Levels in Lake Oroville, California, have dropped dramatically since 2011.
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The Cornell University researcher points out that they have now reached the conclusion that, with climate change and the increase in global temperatures, «the possibility of these megadroughts occurring has greatly increased.»
«Decade-long droughts like the one that caused the famous ‘Dust Bowl’ storms of the 1930s typically occur once or twice a media century in the American Southwest. «.
«In contrast, megadroughts occur once or twice per millennium,» says Ault, who explains that the last of which has been recorded around the year 1150, about nine centuries ago.
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The probability that a «mega-drought» will be recorded in the region has pressed between 20% and 50%, according to scientists.
«Mega-droughts are nothing new, they have been around for millennia. What is new is current climate change, which is increasing the risk of them going.»
According to Ault, scientists such as Park Williams of Columbia University in New York believe the western US has already been experiencing a «megadrought» for the past 15 years.
As stated by Williams in a recent article in the newspaper USA TodayNever since 1150 had such a large area of the west of the country registered a drop in rainfall like the current one for three decades.
future lessons
What worries scientists is how a region whose population has multiplied in recent decades and which continues to grow can cope with a drought that lasts 30 years or more.
For Toby Ault, the current lack of rainfall in places like California may be a foretaste of what is to come and that is why the authorities and the population cannot take note.
«The good thing about the current drought is that water managers, politicians, businessmen and the general public are finally discussing how to make better use of the available water,» Ault says.
image source, Reuters
Experts believe that water conservation measures need to be increased.
«You have to think about how the water is going to be used during periods of drought that can last for decades.»
Glen MacDonald, director of the Institute for Environment and Sustainability at the University of California, Los Angeles, believes that places like California are well prepared in terms of infrastructure to deal with a severe year of drought, «although things get complicated when the lack of rain lasts longer.
«This underlines the need to implement aggressive water conservation and management policies. It is a wake-up call and I think we have to act firmly,» MacDonald said in conversation with BBC Mundo.
«We have become used to droughts that last between 3 and 5 years, and we always assume that things will improve, but there are meteorological models that indicate that the lack of rain could last longer than we think,» says the expert.
«We have to prepare for the worst case scenario. We have to start thinking long term. What if it turns out that we are entering a new dry climate period? I think there are going to be some big decisions to be made.»