No one would think deserts could be threatened, right? But the truth is, they are far more fragile than we can imagine. The plants, animals, and the estimated 500 million people who live in these territories have adapted to the desert climate.
But if temperatures continue to rise, their lives will be in serious danger.
According to a UN Environment Programme (UNEP) report, between 1976 and 2000, the average temperature in deserts rose between 0.5 and 2 degrees Celsius , compared to a rise of 0.45 degrees Celsius in the rest of the world. The greenhouse effect is causing more intense and prolonged droughts, making already scarce rainfall even less frequent.
This translates into a very significant impact on the biodiversity of these ecosystems, where both plant and animal species have developed extraordinary strategies to survive. For example, some plants, such as cacti, have adaptations such as deep roots to reach groundwater and small leaves that limit water loss through transpiration. Animals, for their part, have developed adaptive behaviors, such as the ability to excrete highly concentrated urine or obtain water from their metabolism.
The most affected deserts are the Kalahari in Africa and the Atacama in Chile. In both, one can see how life struggles to survive. But they are not the only ones affected. The decrease in water is causing rivers to dry up , such as the Nile in Egypt and the Colorado in the United States. UNEP warns that if greenhouse gas emissions are not reduced , the water supply will be severely affected, putting the health of desert inhabitants, as well as their crops and livestock, at risk.
If we continue to overexploit groundwater, build infrastructure, or use it for military training, we could completely alter the landscape. Nevertheless, Kaveh Zahedi, deputy director of the UNEP World Conservation Centre, asserts that deserts can become the power plants of this century , as well as serve as tourist attractions, or even be sites for discovering new medicines that can improve people's lives.
Deserts, often imagined as vast, arid, and inhospitable expanses of sand, are actually complex and diverse ecosystems that cover approximately one-third of the planet's land surface. Far from being monotonous, deserts come in a multitude of forms, from the golden sand dunes of the Sahara to the rocky landscapes of the Atacama Desert and the frozen expanses of the Arctic.
The defining characteristic of deserts is their extreme aridity. Low rainfall, often less than 250 mm per year, and temperatures that can range from scorching daytime heat to intense nighttime cold, create a challenging environment for life.
However, despite these extreme conditions, deserts harbor a surprising variety of life. Plants and animals have developed incredible adaptations to survive in this arid environment. Plants, for example, have deep roots that seek water underground, small leaves that minimize water loss through transpiration, and mechanisms to store water during droughts. Animals, for their part, have developed strategies to conserve water, such as the ability to excrete highly concentrated urine or the ability to obtain water from their metabolism.
Despite their resilience, desert ecosystems are fragile and threatened by human activity. Climate change, overexploitation of resources, and pollution are some of the factors that put the biodiversity of these regions at risk. The advance of climate change is causing an increase in the frequency and intensity of extreme weather events, which affects not only the living beings that reside in these ecosystems but also negatively impacts the human communities that live in their surroundings.
Deserts are generally classified according to their geographic location, climate, and the causes of their aridity. There are different types:
- Hot Deserts: They are the largest and best known, with high daytime temperatures and minimal humidity, like the Sahara.
- Cold Deserts: They are represented in places like Antarctica, with sub-zero temperatures and precipitation mostly in the form of snow.
- Semi-arid or semi-desert deserts: They have a more marked seasonality with short periods of rain, like the Kalahari Desert.
- Coastal deserts: They have humidity coming from cold ocean currents, but with little rainfall, like the Atacama Desert.
- Interior DesertsFar from seas and oceans, they have very low precipitation rates, often found in Central Asia.
Each type hosts unique ecosystems and specific adaptations of flora and fauna to survive in extreme conditions.
- Increased temperaturesGlobal warming is increasing temperatures, exacerbating aridity and driving desertification.
- Alteration of Precipitation PatternsChanges in weather systems could cause the already scarce rainfall in deserts to become even more erratic.
- Increase in Extreme EventsMore intense sandstorms and longer droughts are affecting desert ecosystems.
- Effects on Biodiversity: Flora and fauna specialized in desert habitats are threatened by the rapid alteration of their environment.
- Impact on Human Communities: Populations that depend on these environments for their subsistence face greater challenges in obtaining resources such as water and food.
Deserts occupy approximately one-third of the planet's land surface. Among the largest are:
- Sahara desertLocated in Africa, it is the largest hot desert in the world, with more than 9 million square kilometers.
- arabian desert: It extends across several countries in the Middle East, reaching nearly 2,3 million square kilometers.
- Gobi desertIn Asia, mainly in Mongolia and China, it covers about 1,3 million square kilometers.
- Kalahari desert: Also in Africa, it has an area of ​​nearly 900,000 square kilometers.
- Great Victoria Desert: It is the largest in Australia, with an area of ​​more than 647,000 square kilometers.
These vast areas are evidence of the influence of climatic factors and natural processes on the formation of deserts. Furthermore, it is estimated that more than 75% of Spain's surface area is at risk of desertification, and 70% of its watersheds present high or severe levels of water stress, according to Greenpeace. This phenomenon of desertification, which is the degradation of land in arid, semi-arid, and dry sub-humid areas, is aggravated by climate change, as well as by the growing demand for water resources.
Climate reports conclude that deserts are undergoing profound changes that will have significant implications for water supplies for people, animals, and plants in these regions. It is crucial to implement effective policies to mitigate exposure to climate change, protect ecosystems, and ensure the livelihoods of communities that depend on these environments.
The combination of desertification and climate change also influences increased soil erosion. Recent research has shown that desert areas face alarming vulnerability linked to the increasing frequency of extreme weather events. For example, flash floods in areas that rarely experience rainfall can devastate the environment, affecting not only wildlife but also human communities. The most intense rainstorms are proving to be just as damaging, if not more so, than prolonged droughts.
Desert conditions are also conducive to the development of renewable energy. Arid areas have high potential for solar energy, thanks to their extensive exposure to the sun. Kaveh Zahedi also highlighted the importance of using these spaces as sustainable solutions for future energy needs, albeit with careful and responsible resource management.
Deserts have been an integral part of human history and have influenced the culture, economy, and ecology of the regions they inhabit. Local communities' traditional knowledge of water management and agriculture in arid conditions is essential for developing effective strategies to address desertification and climate change.
The history of deserts is also a story of resilience. The species that inhabit these ecosystems have evolved over millennia to adapt to a hostile environment. Now, the question is whether humanity can adapt as effectively to the changes we ourselves have caused.