Friday, December 3

Desertification is making the Earth barren, but a solution is still within reach | David R Montgomery


Tthe record heat waves of its summer and the dramatic fires in the south Europe and the American west they were stark reminders that the climate crisis has arrived. But as the world warms, a calmer and lesser-known crisis also unfolds. Desertification, long viewed primarily as a threat to developing nations, is also looming for Europe and North America, as worsening droughts bake soils already degraded by conventional farming and grazing practices.

In Spain, for example, about a fifth of all land is now in high ground. risk desertification, as does much of the agricultural land in Italy, Greece and western north america.

Desertification is a process that turns fertile farms into barren land through the interactive effects of human activity and climatic extremes. Soil degradation is the decrease in the soil’s ability to support crops and livestock, either due to the erosion of the fertile soil layer or the loss of nutrient-rich and water-retaining soil organic matter and life supporting. Semi-arid grasslands such as the Sahel and western plains of North America are more vulnerable because the loss of native drought-tolerant vegetation can trigger rapid soil degradation and loss of agricultural productivity.

However, a changing climate is not the only cause desertification. How we treat the land, how we farm and farm the ranch, is also important. Healthy, lively soils better retain moisture that falls on farmers’ fields.

Desertification is a growing problem. A 2018 report by EU auditors found that an area twice the size of Portugal had fallen at high risk of desertification in the previous decade, only in Europe. In recent decades, 13 EU states they declared themselves affected given that the Mediterranean region experienced a significant expansion of dry lands – regions with low rainfall. Soil degradation is estimated to cost the EU tens of billions euros per year, and yet the way farmers treat their soil remains essentially unregulated with respect to soil health on both sides of the Atlantic.

The threat of desertification and land degradation will increase as the climate crisis progresses. To 2018 report found that land degradation already affects the well-being of at least 3.2 billion people, more than a third of humanity. Between 1982 and 2015, unsustainable land use practices already desertified 6% from the drylands of the world. Globally, the area of ​​drylands is projected to increase by up to 23% This century.

Rising temperatures are already expected to reduce the yields of staple crops such as wheat, rice, maize and soybeans, in 3-7% for every 1 ° C rise. In Washington state, for example, wheat yields fell this year by almost half due to a devastating drought. Madagascar is now facing a situation induced by climate change. famine.

But it’s not just droughts that are causing the problem. Agricultural practices that degrade the soil reduce the resilience of crops as worsening conditions affect crops. Drylands in particular are sensitive to degradation of both tillage and overgrazing. If it continues, soil degradation will further increase the threat to agricultural production in regions on which humanity depends for food.

Looking back through history, it is clear that desertification and land degradation are not new problems. Since the advent of agriculture, humanity has degraded as much as one third of the world’s potential agricultural land. This pattern reflects both a long history of tillage-induced erosion and the more recent adoption of modern agricultural practices that deplete soil organic matter and alter soil ecosystems. Unfortunately, we are repeating the problem on a global scale.

Now conventional agricultural and livestock practices that degrade the soil make farmers around the world increasingly dependent on large amounts of chemical fertilizers and pesticides. Deterioration of soil health due to depletion of soil organic matter and soil life is increasingly recognized as a critical problem.

According to a 2015 UN report we are on track to degrade another third of the world’s agricultural lands over the course of this century. We are leaving the land more fragile and our crops more vulnerable as climate change is creating unprecedented environmental pressures.

To combat and reverse the growing threat of desertification and land degradation, we must reduce carbon emissions and change the way we farm. We don’t have to relearn the lessons of past societies that degraded their land. But to avoid its fate, we must reorient agriculture around farming and grazing practices that regenerate soil health.

Several years ago, I visited And wrote on farms and ranches around the world that had restored the fertility of previously degraded lands. I saw how regenerative agriculture and grazing based on soil building practices can reverse soil degradation, rebuild soil health, and make farms resilient to extreme weather, while maintaining good crops. But it requires replacing conventional agricultural practices that rely on intensive tillage and the massive use of chemical fertilizers with practices that put soil health first.

In addition to intensive efforts to reduce carbon emissions from fossil fuels, we need a sustained global push to rebuild the health of the world’s agricultural soils. Fortunately, the latter to be able to help with the first. Agricultural practices that build healthy soil convert carbon dioxide captured from the atmosphere into soil organic matter. While the potential to store carbon in the soil remains Highly debated, even low end estimates it would help curb climate change.

Soil is the basis of life on Earth. Now that we are faced with a century of increasingly volatile climate and a growing population, we need it in its best form to sustain us. Humanity must take seriously our collective intergenerational responsibility to preserve the health and fertility of our land, wherever we live.


www.theguardian.com

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