Soil isn’t sexy. For the 54 percent of us globally that live in urban areas, the kind of dirt that generates what we all need to eat and survive is estranged from our daily lives. The dirt we see used for potting decorative trees and shrubs on highways is totally divorced from the purpose of producing food sources.
But soil that is able to generate viable crops is rapidly on the decline, according to senior UN official Helena Semedo. Half of the topsoil on the planet has been lost in the last 150 years, and it can take decades, if not centuries, to regenerate. Numbers suggest only 60 years of viable topsoil left at the current rate of degradation and increased usage.
The loss of arable land has been caused by a number of factors, most of which are tied to human development. Soil degradation is caused primarily by livestock overgrazing (35 percent), industrialized agriculture (28 percent), deforestation (30 percent), and urban industrialization (4 percent). Some topsoil degradation is caused by natural topographic factors, such as steep inclines as rainfall naturally washes this soil away faster. But the human factor is not entirely removed from these instances of “natural” degradation, as rainfall increases globally have been directly linked to carbon emissions for decades.
According to statistics reported by FAO, 99.7 percent of human food (calories) comes from the land, while 0.3 percent comes from oceans and other aquatic ecosystems. Maintaining and augmenting the world food supply fundamentally depends on the productivity and quality of soil.
Degraded soil will mean that 30 percent less food will be produced over the next 20-50 years. As global population steadily increases and food availability decreases, widespread starvation seems like simple math.
Soil degradation even directly contributes to rising sea levels, according to experts. According to Professor John Crawford of the University of Sydney, “Even moderately degraded soil will hold less than half of the water than healthy soil in the same location.” This means that good soil keeps water close to plant roots, requiring less water to properly nourish the crops. When the soil is degraded, more water is needed to irrigate.
“However, a staggering paper was published recently indicating that nearly half of the sea level rise since 1960 is due to irrigation water flowing straight past the crops and washing out to sea,” says Crawford.
Unsurprisingly, soil erosion is most serious in underdeveloped regions such as Africa, India and parts of South America. If the food supply goes down, obviously the price goes up. These regions are also already some of the top agricultural producers of globally consumed crops. This means that agricultural production exported globally is hardly consumed by the people that actually live there, but is rather shipped around the world to feed aforementioned urban dwellers, mostly in developed nations such as the United States and Europe.
So these regions are not only suffering soil erosion due to messy agricultural practices (placed on them by global demands for food exports), but also suffering from malnutrition and exorbitant food prices.
Soil may be unsexy, but things could get a lot uglier if there isn’t some immediate change.