To battle climate change, dig into healthy soil
Stressed trees. Dying vegetation. Dry creek beds. Soaring temperatures. This summer hammered home the impacts of climate change on San Antonio and the Texas Hill Country.
Lost in much of the discussion around drought conditions is the health of our soil, and how it can help us adapt to and mitigate the effects of climate change.
How could a bunch of dirt help us fight climate change? Well, actually, dirt won’t. Soil, on the other hand, will. There’s a difference. Soil has dirt in it, sure, but it’s also alive and full of microorganisms that allow plants to access the minerals and nutrients vital to life. Unlike dirt, healthy soils provide a multitude of ecosystem services that can help us as we face the impacts of climate change and work to create a more resilient future.
Soil is the world’s largest carbon sink. It holds more carbon than the Earth’s plants, animals and atmosphere combined. But soil can also become a large source of carbon emissions, and unfortunately, we’re losing healthy soil across the planet 10 to 100 times faster than it can form. Without better land management and preservation, over the coming century, Earth’s soils are projected to contribute more greenhouse gases to the atmosphere than they will remove.
Healthy soils are also more important to our groundwater supply than we might think. Just a 1% increase in soil organic matter allows soil to hold up to an additional 20,000 gallons of water per acre — vital for a region dependent on an aquifer for the majority of its water supply.
Degraded soils contribute to stormwater runoff and erosion, reducing an aquifer’s ability to recharge. Soil degradation occurs through poor farming and range land practices, deforestation and, in urban areas, poor construction operations and landscape management.
Soil preservation and restoration efforts are underutilized but important tools to mitigate climate change. Managing our soils to improve their health allows us to realize a host of benefits. Increasing soil organic matter will not only increase the soil’s ability to remove greenhouse gases from the atmosphere, it will also reduce stormwater runoff, recharge groundwater, biofiltrate our drinking water, contribute to more nutrient-rich plant life and allow us to reduce irrigation.
San Antonio is working to understand just how large this potential is with its ongoing San Antonio Soil Carbon Project, which studies how green infrastructure affects carbon sequestration and water quality at 13 area parks.
Preservation of existing natural lands is perhaps the most obvious way to combat soil degradation. Five of the eight counties in San Antonio’s Metropolitan Statistical Area lie within the Edwards Aquifer contributing or recharge zones. Preserving and improving land within these zones would allow soil to continue to absorb greenhouse gases and filter our drinking water as it makes its way into the Edwards Aquifer. Within the urban areas of our region, soil restoration in our parks and green space will help mitigate carbon emissions and control stormwater runoff.
Healthy soil means more resilient communities. We can’t afford not to invest in land preservation and restoration. The cost of investing now will, in the long run, help avoid future costs to build and maintain infrastructure to replace what we lost through inaction.