Deserts | National Geographic
[Narrator] Wind whips over a barren wasteland. Vast nothingness as far as the eye can see, or so it may seem. Creatures peek out of burrows, scurry across the sand, and soar through the sky, revealing a landscape not as lifeless as it might first appear.
Definition
Deserts are often defined as areas of land that receive less than 10 inches of rainfall each year. These regions are low in humidity and can even be moisture-deficient, evaporating water faster than it is received. While most deserts are found in the mid-latitudes, these diverse ecosystems occur on all seven continents and make up nearly one-third of Earth’s total land mass. Deserts are sometimes classified into four major types: subtropical, semiarid, coastal, and polar.
Types
Subtropical deserts are found along the equator, and the Tropic of Cancer, and the Tropic of Capricorn. They are the hottest deserts on Earth, with daytime temperatures that can reach up to 120 degrees Fahrenheit. Semiarid deserts are located in Asia, Europe, and North America. These cold-winter deserts often form when tall mountain ranges block moisture through a process called the rain-shadow effect. Coastal deserts form alongside the tropical western edges of certain continents. Despite their proximity to water, coastal deserts remain dry. Polar deserts are found in the Arctic and Antarctic. The other end of the extreme, winter temperatures in the Antarctic Desert average around minus 50 degrees Fahrenheit.
While deserts experience extreme temperatures and receive very little precipitation, they are still important habitats for plants and animals. Desert animals, such as the coyote, have evolved to withstand harsh desert conditions by burrowing into the cool ground and emerging at night, when desert temperatures drop. Many desert plants, including the saguaro cactus, have established long and shallow root systems to better absorb what minimal moisture might be present in the ground. Highly specialized to survive in such a harsh environment, desert wildlife is particularly vulnerable to ecological changes.
Existing deserts have become less habitable because of rising temperatures that dry up scarce water resources and increase the risk of wildfires. Additionally, new desert areas are beginning to form through desertification. This phenomenon occurs when factors such as deforestation, climate change, and resource mismanagement degrade the biological productivity of a region, thereby creating a desert. For instance, in Central Asia, poor irrigation practices and excessive water usage dried up the Aral Sea and formed the youngest desert on the planet.
Desertification
But by practicing responsible agriculture, better management of limited water resources, and limiting further development, it may be possible to curb desertification while protecting our surprisingly rich desert ecosystems.
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whip over /wɪp ˈoʊvər/ (v) – To move or pass quickly and forcefully over something.
SYN: sweep, rush
Example: The wind whipped over the barren wasteland, creating a dramatic scene. - peek out /piːk aʊt/ (v) – To appear slightly or partially from behind something.
SYN: emerge, peer
Example: Creatures peeked out of their burrows to check the surroundings. - scurry /ˈskʌri/ (v) – To move quickly with small, short steps.
SYN: dash, hurry
Example: The animals scurried across the sand, seeking shelter. - humidity /hjuːˈmɪdəti/ (n) – The amount of water vapor in the air.
SYN: moisture, dampness
Example: Deserts have very low humidity, which makes the air feel dry. - moisture-deficient /ˈmɔɪstʃər dɪˈfɪʃənt/ (adj) – Lacking sufficient water content.
SYN: dry, arid
Example: Desert soil is often moisture-deficient, making it hard for plants to grow. - evaporate /ɪˈvæpəreɪt/ (v) – To change from a liquid into a vapor.
SYN: dry up, vaporize
Example: Water quickly evaporates in hot desert conditions. - mid-latitudes /mɪd-ˈlætɪˌtjuːdz/ (n) – The regions of the Earth between the tropics and polar areas.
SYN: temperate zones
Example: Most deserts are located in the mid-latitudes. - make up /meɪk ʌp/ (v) – To form or constitute something.
SYN: constitute, compose
Example: Deserts make up nearly one-third of the Earth’s landmass. - subtropical deserts /ˌsʌbˈtrɑːpɪkəl ˈdɛzərts/ (n) – Deserts located in subtropical regions.
SYN: hot deserts
Example: The Sahara is one of the largest subtropical deserts. - The Tropic of Cancer /ðə ˈtrɑːpɪk əv ˈkænsər/ (n) – A line of latitude about 23.5° north of the equator.
Example: The Tropic of Cancer passes through many subtropical deserts. - The Tropic of Capricorn /ðə ˈtrɑːpɪk əv ˈkæprɪˌkɔːrn/ (n) – A line of latitude about 23.5° south of the equator.
Example: The Tropic of Capricorn marks the southern boundary of subtropical deserts. - degree fahrenheit /dɪˈɡriː ˈfærənˌhaɪt/ (n) – A unit of temperature measurement.
Example: Desert temperatures can reach 120 degrees Fahrenheit during the day. - Semiarid deserts /ˌsɛmiˈærɪd ˈdɛzərts/ (n) – Deserts that receive slightly more rain than arid deserts.
SYN: drylands
Example: The Great Basin in the U.S. is an example of a semiarid desert. - proximity to /prɑːkˈsɪmɪti tuː/ (n) – The state of being near something.
SYN: nearness, closeness
Example: Coastal deserts are formed due to their proximity to large bodies of water. - Arctic /ˈɑːrktɪk/ (adj) – Relating to the area around the North Pole.
SYN: polar
Example: Polar deserts are found in the Arctic and Antarctic regions. - Antarctic /ænˈtɑːrktɪk/ (adj) – Relating to the area around the South Pole.
SYN: polar
Example: The Antarctic Desert has extreme cold temperatures. - precipitation /prɪˌsɪpɪˈteɪʃən/ (n) – Rain, snow, or other forms of water falling from the sky.
SYN: rainfall
Example: Deserts receive very little precipitation annually. - withstand /wɪðˈstænd/ (v) – To resist or survive something difficult.
SYN: endure, survive
Example: Cacti have adapted to withstand harsh desert conditions. - burrow into /ˈbʌroʊ ˈɪntu/ (v) – To dig and move into a hole or tunnel.
SYN: dig, tunnel
Example: Desert animals often burrow into the ground to stay cool. - minimal moisture /ˈmɪnɪməl ˈmɔɪstʃər/ (n) – Very small amounts of water.
SYN: slight dampness
Example: Some desert plants survive on minimal moisture. - ecological changes /ˌiːkəˈlɑːdʒɪkəl ˈʧeɪndʒɪz/ (n) – Alterations to ecosystems and environments.
SYN: environmental shifts
Example: Desert wildlife is vulnerable to ecological changes. - scarce water resources /skɛrs ˈwɔːtər rɪˈsɔːrsɪz/ (n) – Limited supplies of water.
SYN: limited water
Example: Rising temperatures dry up scarce water resources. - desertification /dɪˌzɜrtɪfɪˈkeɪʃən/ (n) – The process of land becoming desert.
SYN: land degradation
Example: Deforestation contributes to desertification in many regions. - poor irrigation practices /pʊr ˌɪrəˈɡeɪʃən ˈpræktɪsɪz/ (n) – Inefficient methods of supplying water to crops.
SYN: bad water management
Example: The Aral Sea dried up due to poor irrigation practices. - excessive water usage /ɪkˈsɛsɪv ˈwɔːtər ˈjuːsɪdʒ/ (n) – Using more water than is needed.
SYN: overuse of water
Example: Overpopulation led to excessive water usage in the region. -
curb /kɜːrb/ (v) – To limit or control something.
SYN: restrain, reduce
Example: We must take measures to curb desertification and protect the environment.
Deserts are defined as areas receiving less than 10 inches of annual rainfall and occur across all continents, covering nearly one-third of Earth’s land. They are categorized into four types: subtropical (hot and dry), semiarid (cold-winter), coastal (near water yet dry), and polar (extremely cold). Despite harsh conditions, deserts support unique plants and animals adapted to survive with minimal moisture and extreme temperatures. However, rising temperatures, wildfires, and human activities like deforestation and poor water management contribute to desertification, making deserts less habitable and creating new desert areas, such as the Aral Sea. To curb desertification, responsible agriculture and sustainable water management are essential for preserving desert