Soil is a vital source of food and medicine, home to a vast reservoir of biodiversity and an important carbon sink. Soil is one of the most valuable natural resources on earth, yet 30 percent of our soils are degraded. Soil is one of the most ubiquitous and underappreciated substances on earth.
Although we are all around us – in fields and gardens and under our feet as we walk the concrete and asphalt of city streets – soil is often taken for granted. Yet in several intriguing ways, this wondrous substance holds the key to life on Earth.
It helps produce our food, filters and purifies our water, reduces flooding, regulates the atmosphere and plays a crucial role in driving the carbon and nitrogen cycles. It is also one of the most biodiverse habitats on earth.
Most of us are already aware of the importance of forests and trees in reducing the amount of harmful CO2 in the atmosphere; but few realize that soil plays an even more important role.
Plants extract carbon dioxide from the atmosphere in a process called photosynthesis, and some of that carbon is then stored or “captured” in the soil as fresh plant debris and heavily decomposed material known as humus. The soil stores an extraordinary amount of carbon: three times as much as in the atmosphere and twice as much as in all plants and trees.
These organic compounds are highly enriched in carbon and are referred to as soil organic matter (SOM), which sequesters carbon in the subsoil in a stable and environmentally friendly manner.
However, when soil is damaged or degraded, it can release harmful carbon dioxide or methane back into the atmosphere, thereby accelerating — rather than slowing down — the effects of climate change.
As John Scott, Zurich’s Head of Sustainability Risk, says: “That’s why the way we use land for farming is so important. For example, by switching from intensive farming to organic methods, we could dramatically change the country’s emissions profile. With proper management, soils become healthier and more fertile – and also store more carbon.”