Many places suffer from high temperatures throughout the summer season. In fact, the heat can be really extreme for several days, weeks or even months. This phenomenon is known as heat wave, and has very important consequences on health, climate and environment.
In Spain we are facing one of the three driest hydrological years since 1961. Our crops suffer the vicissitudes of the lack of water while we look at the sky and watch the news hoping that, as soon as possible, the weather will give us a respite to recover the water from our reservoirs. “There is a drought” is what we hear when talking about this worrying issue. But do we really know what kind of drought we are facing?
Types of drought
Drought can be defined, in a general way, as a natural condition that occurs in a certain region, in the absence of rainy periods, or when they are very short. This causes a major impact on the habitat and climatic conditions of the environment, even becoming incompatible with life.
But there is a wide variety of types of drought:
Meteorological drought: it is generated when there is a continuous lack of rainfall. It originates due to a global behavior of the atmospheric system, which is influenced by both natural factors and those caused by human action, for example, deforestation or the increase in greenhouse gases. This type of drought is linked to a specific region where these meteorological circumstances occur.
Hydrological drought: It is the decrease in the availability of surface and/or groundwater in a given area during a given time period, compared to historical values. This hydrological drought can cause the complete dissatisfaction of the demand for water.
Agricultural drought: It is the lack of moisture to meet the needs of a crop in a given place and time. In rainfed crops it is linked to meteorological drought, while in irrigated crops it is more linked to hydrological drought.
Socioeconomic drought: it is the effect of water scarcity on people and economic activity as a result of any of the types of drought.
Causes of the lack of water problem
Although we clearly understand drought as a phenomenon associated with climate change and global warming, the truth is that it is convenient to identify cycles of meteorological drought with recent phenomena. Thus, the current situation of drought that we are suffering in our country and in other areas of the planet seems to be clearly related to the La Niña phenomenon , an anomalous cooling of the waters of the Pacific Ocean. It is the conclusion reached by experts such as Juan Jesús González, physicist, researcher in atmospheric dynamics and spokesman for the State Meteorological Agency (Aemet). According to their own statements, the current period of drought that we are facing is the consequence of an anticyclonic blockade that causes a lack of sustained rains over time.
In addition, another clear indicator is the strong thermal oscillation that we have been experiencing at the end of winter. Thermal differences of more than 25ºC between maximum and minimum that have led us to live a “summer winter” in some parts of the country.
Other areas of the world are also suffering these consequences, even more noticeably than in Spain. Thus, the western United States, Latin America and Morocco are facing their worst dry season in the last 30 years.
Global warming, the ultimate culprit
But let’s not fool ourselves. Global warming is, without a doubt, the cause of these alterations in rainfall and in the thermal increase of the planet. This is a reality that the experts responsible for the IPCC (International Panel of Experts on Climate Change) underline in all their reports. They indicate that if the global levels of greenhouse gas emissions are maintained, the heat waves that hit our countries would become annual.
Much of the seagrass beds could disappear by the middle of this century, taking with them the rich biodiversity they harbor. We will also experience more fires, crop losses and agricultural land. And of course, access to clean drinking water globally will be drastically affected. This is because the increase in demand without the renewal of aquifers due to drought could deplete water reserves in the most populated areas of the planet.
These experts also indicate that the situation could not be so devastating if our consumption habits are drastically changed. Changes that lead to a significant reduction in the emission of greenhouse gases.