The citizens of the capital are going from catastrophe to catastrophe. And in case we lack calamities, we now have the risk of suffering years or even a century of drought in the Valley of Mexico. Something that has already happened in the past, but can now be intensified by climate change.
Researchers from the Center for Atmospheric Sciences (CCA) of the UNAM indicated that, although the drought that is currently registered in the country “is on its way out”, in the coming years the situation will worsen due to the effects that the global warming on the planet.
In the remote press conference “Impact of the drought in Mexico”, researcher Benjamín Martínez López said that from 1870 to 2018 a sustained increase in rainfall was observed in Mexico City. We are in a period where it rains more and more; “It could be good news, however, in a study where two thousand years of indirect records (from a cave) were analyzed, it was established that there have been wet periods, but also brutal droughts that do not last one or two years, such as those that we have suffered if not decades and even hundreds of years ”.
For this reason, it is important that experts join forces to determine if what the indirect historical records say can be reproduced with models, understand what happened and specify when it could happen again, said the university student, according to a statement from the UNAM.
In the Valley of Mexico, he warned, the worrying thing is that we can go from a stage of abundant rains to a dry period that lasts for tens of years or more than a century, “because it has already passed and there is a latent risk that it may return to happen, and then yes we would be in big trouble. I would dedicate a great effort to investigate what happened, understand the causes, and be able to simulate it, to make predictions, “he reiterated.
Meanwhile, Christian Domínguez Sarmiento, also a member of the CCA, explained that drought is a deficiency in precipitation over an extended period, which results in a shortage of water that causes adverse impacts on vegetation, animals and people; That phenomenon, of course, can vary from region to region.
In addition, human factors such as demand for the liquid and its management can exacerbate the impact on a region. “Depending on the degree of pressure on water resources and water management, it will be vulnerability and consequently the risk of disaster associated with drought.”
Deforestation and land use change (that is, eliminating forests and instead establishing cities or agricultural fields), has diminished the infiltration capacity of water, with serious consequences on ecosystems, such as loss of biodiversity and fires, he added. the expert.
He clarified that drought is not the same as aridity; The latter means that a place or region has a low rainfall regime, that is, that it rains little during the year, as it happens in desert areas. In Mexico there are great variations, since regions such as Sonora and Chihuahua, on the border with the United States, are under extreme drought conditions, while the Yucatan Peninsula does not have this problem.
During the 2010-2012 drought, the largest in 80 years, 95 percent of the national territory was affected by some type of drought, from “abnormally dry” to “exceptional drought”; in which it has been presented since 2020, 84 percent of the territory is under some condition of drought; however, the extreme affects a smaller area today than it did a decade ago.
After mentioning that this phenomenon has an impact on the price of agricultural products, he recalled that the cyclonic season begins in the Pacific on May 15, and on June 1 in the Atlantic Ocean. Tropical cyclones help reduce the effects of hydrological drought and fill dams, especially those in the north of the country.
For the 2021 hurricane season, from May to November, the National Weather Service expects 15 to 20 systems in the Atlantic, above the average, which is 14; and in the Pacific 14 to 20 are forecast, close to the average, which is 16. In summary, a slightly active season is expected in both oceans.
However, he acknowledged that the problem with this type of forecast is that it does not make it easy to identify the regions that could be affected, since these systems have the possibility of recurring or being lost in the ocean; by moving away from our territory they would “steal” the humidity. It is important that in the future it is determined which trajectory will predominate in a season, and in the CCA we investigate if that can be done and with what reliability.
According to the International Institute for Climate Research and Society at Columbia University, United States, at the moment there is a 40 percent probability that the temperature will be warmer than in other years for the coming months (June-August) , and that it will rain less, mainly in the states of the Gulf of Mexico, he said.
However, he clarified, this type of forecast does not include the effect of tropical cyclones. “You have to understand that climate forecasts have limitations,” he concluded.