Soil is the literal skin of the Earth. On average, only 50 centimeters thick, the so-called Pedosphere contains a whole zoo. Just take a handful of dirt and guess how many organisms you picked up. The equivalent to all World Cup viewers worldwide: 1 billion.
For instance, soil contains 1,500 billion tons of organic carbon — more than Earth’s atmosphere and all the plants together — making it a key player of climate change. Therefore, soil biodiversity is very valuable for humans, providing food, livestock, fiber, energy, water and mining resources.
One centimeter of fertile soil needs, on the average, 1,000 years to develop. At a much faster rate, however, it gets destroyed.
During the time it took you to read until here, the population increased by 500 people; carbon dioxide in the atmosphere rose by 18,000 tons; 75 hectares of tropical forest got cut; 30 hectares of soil degraded; 70 hectares turned into deserts; and 17 hectares were sealed by urban encroachment...
12 million hectares are transformed into new man-made deserts each year...
To make matters worse, drylands emit an estimated 300 million tons of carbon dioxide as a result of desertification each year, which is about 4 percent of the total global emissions, fueling global warming.
This becomes a vicious circle: when the ground heats up, organic matter decomposes quicker, reducing soil fertility and again releasing CO2 into the air.
A land degradation-world trip shows the scope: already during the 1930s, North America’s Great Plains turned into the Great Dust Bowl. Farms were covered by dust and hundreds of thousands of families were driven from their land by eight years of black blizzards.
More recently, such blizzards also haunt China’s Yellow River Basin, blowing away 1.6 billion tons of loess, a crumbly, fertile soil, deposited over millennia.
In Haiti the loss of one-third of its top-soil cover is the root cause of poverty and unrest. The country’s agriculture is on its knees, after the majority of the once forested country turned into the most denuded landscape.
Also, a large part of sub-Saharan Africa suffers poverty from land degradation, since the planted crops leach the nutrients from the soils, while poor irrigation practices in Australia, the Middle East and India saturate land with salt.
In other parts of Asia, such as Kazakhstan, Uzbekistan and northern China, the desert is growing by 3600 sq km a year — an area leading to new dust bowls that choke Beijing, among others.
Land degradation and desertification will remain a huge problem, if the Earth’s soils are not appreciated as the living, dynamic interfaces they are. Thus, already in the mid-1980s agricultural economist Lester Brown cautioned that civilization might run out of soil before oil.
But unlike oil, soil is a renewable resource, if we only treat it right. That land degradation can be prevented is not even rocket science.
From their dust bowl, US farmers, for instance, learned to use new plowing methods to curb erosion, and started to grow cover crops to retain soil between planting seasons. But instead of engineering our way out, we can also ask what nature would do.
Indeed, biodiversity and eco-system services themselves can prevent forests and fertile land to turn into deserts. If we only let them. This so-called ecosystem-based adaptation is often easiest and cheapest, especially in the face of climate change. Through livestock planning and monitoring, for example, holistic land management eases the natural recovery of grasslands for future generations.
“Land Belongs to the Future,” as the theme of this year’s World Day to Combat Desertification on June 17, rightly spotlights “Let’s Climate Proof It.”
This effort to increase the attention given to land and soil within climate-change adaptation is part of a bigger global movement, aiming at Zero Net Land Degradation.
You can do your part. Let people know about the solutions to desertification and buy food and products that are produced in a way that reverses desertification.
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