The lands of the Mongols have already entered a new climate era

Science

By CAPosts 26 November, 2020 - 12:59pm 65 views

There are areas of the planet that have already entered a new climate era. The Arctic is, for scientists, the best example . But there are other regions of the world that, driven by climate change, have also reached a point of no return. In Mongolia, in the east of central Asia, they have been three decades with a succession of waves and droughts not suffered in almost three centuries. A study with the tree rings indicates that the soils are drying out to the point that the semi-arid climate of those lands has become directly arid.

Climate change is for most something that is yet to come. Depending on what is done with the emissions, dates are set for the new climate era: that if 2030, 2050 or 2100, the most common. But in the lands of the Mongols they have had a climate since the 90s that was not the one they knew. The average temperature has risen more than 1º, with an even more marked increase in winter. The lakes have lost more than a quarter of their water in the last five years. The worst thing is that summer after summer the frequency and intensity of heat waves and the duration of droughts increase.

Now a group of researchers has wanted to know if these changes fall within the natural variability of the climate or are the beginning of a new climate era. To do this, they analyzed the rings of five long-lived tree species from almost 80 locations in this part of Asia. Of annual formation, the circles of the logs record the weather in the past, being able to infer the temperature and even the humidity of the environment.

The results, published by the scientific journal Science , indicate that never in the past 260 years had there been produced the succession of heat waves and droughts that the region has experienced since the end of the last century. The environment, air, water and soil have become warmer and drier, with an acceleration of the process since the 90s of the 20th century.

Not only are large bodies of water disappearing. Soil water is also disappearing ”Jee-Hoon Jeong, researcher at Chonnam National University (South Korea) and co-author of the study

"We are now seeing that not only are large bodies of water disappearing," says researcher from Chonnam National University (South Korea) and study co-author Jee-Hoon Jeong in a note. "Soil water is also disappearing," he adds.

The process of change is almost devilish. In its simplest version and under normal conditions, the humidity in the soil from past rains works as a thermal regulator: when the heat is on, the water evaporates, lowering the temperatures. But climate change would have disrupted this system by intensifying heat waves, removing almost all the moisture from the soil.

“The result is more heat waves, which means more loss of water from the ground, which causes more heat waves and so we don't even know where ”, maintains the scientist from the University of Gothenburg (Sweden) and co-author of the research Deliang Chen.

For climatologists it is a big problem to say when one climate state has changed to another. In the past they have been processes that, except in catastrophic events, took their time. The new dynamics observed in Mongolia is, for the study authors, proof that this region of the planet has crossed the threshold.

"It is the same effect that is occurring in the Mediterranean region," says the expert in dendroclimatology (the Science of Inferring Climate from Tree Rings) from Pablo de Olavide Raúl Sánchez-Salguero University. "With this work they show that there has been a drastic change since the 70s in these two variables," he adds, referring to soil moisture and heat waves. One of the most far-reaching consequences of this new pattern is forest decline, which, for example, is observed in Mediterranean countries. And trees, vegetation, are the pillars of most ecosystems.

Climate variability expert Daniel Griffin, from the University of Minnesota (USA) warns: “It's one thing to accept that normal climatic conditions are changing. However, what worries me the most is thinking about the extreme events to come: how intense will they become? For Griffin, who has reviewed the study and its conclusions, if the new normal is extremely dry and warm compared to historical records, "the future extremes could well be very different from what we have seen so far."

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Source: Elpais

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Science Climate change Global warming Climates Drought Central asia Mongolia