by Deserts can take different forms, from vast scorching sands to enormous ice sheets. But what are the most vast hot and cold deserts on the planet? And what kinds of life can survive in these extremely dry places?
To answer this record-breaking question, it’s important to consider what exactly makes a desert a desert. By Jonathan Wille (opens in new tab)Any region that receives less than 9.8 inches (25 centimeters) of precipitation per year qualifies as a desert, says Antarctic meteorologist and climatologist from the University of Grenoble in France.
Considering all these regions, Antarctica It is characterized as the world’s largest cold desert and Sahara It is the largest hot desert.
“At 14.2 million square kilometers [5.5 million square miles]”Antarctica is the world’s largest desert,” Wille told Live Science. “It is believed that parts of Antarctica, such as the McMurdo Dry Valleys, have had no precipitation for 14 million years.” epic lack of rainfall It is largely due to cold temperatures, mountains blocking nearby clouds, and strong winds that suck moisture from the air.
Even for a desert, this region is extremely arid. According to scientists who are part of LTER of the National Science Foundation (opens in new tab) According to the (Long Term Ecological Research) project in Antarctica, the McMurdo Dry Valleys have no snow or ice, except for a few lakes that are permanently covered with ice. But not completely barren. There are microbes, mosses and lichens that can tolerate dry deep freeze.
Related: Why are deserts so cold at night?
Wille, who spearheaded 2021 research in the journal JGR Atmospheres (opens in new tab) When looking at Antarctic precipitation, one thinks this frozen desert is often overlooked. While Antarctica’s remote interior is mostly devoid of life, more organisms such as aviaries and penguins have set up shops where they can catch fish and other sea creatures from the cold waters, and seals sometimes come ashore, he said.
Predictably, the Sahara Desert stretching across North Africa is the opposite of Antarctica. It measures 3.55 million square miles (9.2 million square km). But while some may see it as a wasteland, it is surprisingly diverse. This desert reveals the diversity of both geographical features and life forms. André Vicente Liz (opens in new tab)PhD candidate at the University of Porto in Portugal.
“The Sahara presents obvious geographic features that greatly contradict established perception; [landscape] and different… types [of materials beneath the surface] but also significant spatial variability in climate,” Liz told Live Science.
The diverse landscapes of the Sahara include not only its famous sand dunes, but also rocky terrain, salt flats, mountains, and even savannas that can be water. In the past, there have been drastic changes in the climate of the desert that led to wide biodiversity in different parts of the desert. Liz led a study in 2022. Journal of Biogeography (opens in new tab) discovering Saharan animal species that had not received much attention before.
In hot deserts, cold-blooded creatures thrive because their body temperature adjusts to the temperature of their environment as they move from scorching sunlight to cool burrows. Liz observed many species of small lizards that are particularly well adapted to the arid environment. Some reptiles and amphibians can also hibernate during periods of drought. The Sahara is home to mammals and birds, as well as lizards, snakes, scorpions, insects and ants, and even a few frogs and toads that live in rock pools. Antelope, camel, cheetah, ostrich and desert fox are just a few of the warm-blooded animals that can live in the Sahara.
There are some areas, such as rock pools known as “gueltas”, where biodiversity is particularly high because they serve as refuges for species forced to flee their habitats due to a sudden, unbearable change in weather. In the face of climate change, Liz and her colleagues are studying these regions closely to learn what makes them good spots for survival.
“These areas are known as biodiversity ‘refugia’ and are particularly interesting for conservation planning in the context of the current climate emergency, where they can play an important role as climatic buffers,” he said.
So deserts can be deceptive places that only seem lifeless until something crawls out or slides out. They may be dry, but that means nothing more than monotonous.
