Since the late 19th century, global temperatures have been steadily increasing, and concerns about arid regions and desertification have received much more attention as a result.

One will be forgiven for thinking of a desert as a very hot and dry region with little or no weather activity. For the most part, you would be correct. If you don’t live in an arid area, you may not even consider the fact that this growing phenomenon could impact you in any way.

But you are probably not seeing the whole picture. There is a reason why “desert climate” and “desertification” are terms more frequently used. And there is also a good reason why you should care.

This article explains what a “desert climate” is, the weather associated with it, and how this phenomenon is growing and may affect you.

Before we look at the different types of deserts and the weather associated with each one, as well as the dangers of desertification, one needs to define exactly what a desert is:  

Desert Climate Definition​​​​​​​​​​

A desert climate is defined as the average weather conditions in arid regions with very low rainfall. It results from evaporation exceeding the amount of precipitation over extended periods. As a general rule, a region is classified as a desert when its annual rainfall is less than 25 cm or 9.8 inches.

As will be discussed soon, though, not all deserts conform to this conventional view one may have of a typical desert. Neither does the weather always remain warm and dry, as one would normally expect in a desert.

There are two types of desert climate:

1. 1. Hot Desert Climate
   2. Cold Desert Climate

To better understand these desert climates and the different weather conditions associated with each, we need to take a closer look at both:

Location

Deserts with hot climates can typically be found in the world’s subtropical regions (between 30° North and 30° South). The world’s biggest hot desert, the Sahara, can be found in Africa. Other examples include the Arabian Desert, the Arizona Desert, and the Great Victoria Desert.

Weather

To be classified as having a hot desert climate, an arid region must have a mean annual temperature of at least 18° Celsius (64° Fahrenheit) and an annual rainfall of no more than 200 millimeters (7.9 inches).

The weather in a hot desert climate is, needless to say, very hot and dry. During the summer months, average temperatures of above 30° Celsius are common, with many days exceeding 40° Celsius. Winter months are colder, but temperatures remain high.

A hot desert climate is also characterized by contrasting weather. This is evident in the stark difference between day and night temperatures. Warm days can quickly turn into cold evenings as soon as the sun goes down.

During winter months, it is not uncommon to experience a relatively warm day, while temperatures can drop to freezing point in the evening.

The low rainfall is not mainly due to the region’s geology or sparse vegetation, but rather to the atmospheric conditions that create and sustain desert climates. In many hot deserts, descending dry air suppresses cloud formation and rainfall, while high temperatures can also cause some raindrops to evaporate before reaching the ground.

Location

Deserts with cold climates are often found at higher altitudes or in high-latitude regions, unlike arid regions with hot desert climates. Hard to believe, but Antarctica is considered to be the coldest desert in the world due to the interior’s extremely low average annual precipitation.

They can also be found in temperate zones, often on the leeward side of high mountains. The Gobi Desert in Mongolia is an example of such a desert. Other regions with cold desert climates include the Karagiye Depression, the Patagonian Desert, and the Great Basin Desert.

Weather

To be classified as having a cold desert climate, an arid region must have a mean annual temperature of 18° Celsius (64° Fahrenheit) or below and a yearly rainfall of no more than 200 millimeters (7.9 inches).

As the name suggests, the weather in a cold desert climate is cold and dry. It is characterized by relatively warm summers but also very cold winters, unlike areas experiencing hot desert climates. (Although even the summers may be cold).

It also differs from a hot desert climate in the way precipitation takes place. The little precipitation that does occur is usually in the form of snow rather than rain, especially in areas where the average annual temperature is below freezing point.

It will be clear by now that regions with a desert climate experience harsh weather conditions and a very inhospitable environment. This makes it very difficult, and in some cases impossible, to use such regions for creating viable urban environments or for agriculture.

The problem we are facing is that more regions are becoming increasingly arid and desert-like through a process called desertification. First, we need to know what desertification is:

Desertification Definition​​​​​​​​​​

Desertification is the process through which fertile and habitable land is degraded and becomes increasingly arid as a result of a loss of water, both on the surface and in the ground. The lack of water is closely followed by a loss of vegetation and wildlife. This is mainly a result of human activity.

Some of the leading causes include activities such as deforestation, the overuse of fertile soil, and other forms of overexploitation. Climate change (mainly due to global warming) is considered to be one of the leading causes.

Without getting into a debate about climate change, the fact that the Earth is warming up at a rapid rate, and that desertification is increasing as a result, is a worrying trend with potentially serious consequences. And this is why you should care, as the next section will illustrate.

As stated before, the process of desertification is mostly a result of human activity. Natural changes in climate that occur over thousands of years, turning regions into deserts, rainforests, or swampland, are normal. What we are experiencing with desertification is not.

Land degradation (the deterioration of land to the point where it becomes severely reduced in value for human use) is a consequence of desertification. According to National Geographic, 75% of the world’s land is already degraded.

At the current rate of land degradation, the UNCCD states that 90 percent of land may be affected by degradation by 2050.

The consequences will be devastating, not just for the agricultural sector but for every human being on the planet.

The following is a list highlighting just some of the direct and indirect consequences and impacts of desertification:

1. 1. A dramatic decrease in available and viable land for agriculture.
   2. A steep rise in food prices is a result of a scarcity of produce.
   3. Urban areas in semi-arid regions will be confronted by increasing water shortages.
   4. Affected urban locations and metropolises will experience extreme weather, making living conditions much harder and influencing quality of life.
   5. The above-mentioned conditions will only worsen the effects of the urban phenomenon called the Urban Heat Island. You can read more about this occurrence here.
   6. Without vegetation that acts as a natural barrier that slows down and limits the extent of flooding, large parts of land are now more vulnerable to large-scale flooding.
   7. As more people move away from arid areas to locations with more favorable living conditions, overpopulation becomes a real danger.

Unfortunately, the growth of existing deserts and the emergence of new ones is a reality. So is the far-reaching consequence which will affect every one of us.

The goal of this article was not to spread paranoia. Its simple aim is to explain the growing climate pattern, known as Desert Climate, what it is, and why it is important. It also explains how it relates to desertification and helps you realize how it affects all of us in the long term.

Until next time, keep your eye on the weather!