As a gardener, naturalist, and Director of The Arboretum, I pay close attention to weather and water, particularly since we live in the arid southwest. During the entire 12 years my husband and I have lived here, Arizona has been in drought. Yes, we've had some wetter winters and monsoons, but overall, our state has suffered for 21 years. It's warmer now, too. While I know that 12 years (or even 21 years) of weather observation doesn't constitute a climatic trend, we are indeed experiencing the effects of climate change. Trees and flowers are leafing out and blooming earlier and earlier, potentially disrupting life cycles of pollinators, birds, and other wildlife species. And animals are moving northward. Whoever thought we'd see denizens of the desert, javelina and coati, in Flagstaff?
We at The Arboretum face climate change issues every day. Irrigation needs, wildfire danger, and endangered plant survival are top of mind. We've developed climate science curricula, and host an outdoor interactive Climate Change Center and phenology garden. We are also involved in the Northern Arizona Climate Change Alliance, and offer talks about our changing landscape through that organization.
Dealing with climate change is frustrating; it's become politicized, and it's exhausting to think about. Who can look at photos of starving polar bears and not turn away in helplessness? But I keep on reading and researching, looking for the latest information and hoping to find some new solution on the horizon.
I recently read an article in the NY Times Magazine, "Can Dirt Save the Earth." The article uses several case studies to explore some relatively new concepts, including carbon farming and regenerative agriculture, asking the question: can plants deliberately be used to pull carbon from the atmosphere. They do, of course, already pull carbon by utilizing carbon dioxide in photosynthesis. But what if we were more intentional with our agricultural practices? It turns out that our current land practices generate almost as much carbon as our fossil fuel use for electricity, heat, and transportation. Soil erosion caused by plowing, clear-cutting forests, and intensive grazing release heat-trapping gasses into the atmosphere.
A French-led initiative is looking to increase the amount of carbon held in soils through agroforestry (growing trees and crops together), no-till agriculture (plowing releases carbon), and covering croplands (bare soil releases carbon). In the US, the Marin Carbon Project and the Carbon Cycle Institute conduct research and assist farmers and ranchers in utilizing these techniques. One finding: manure releases nitrous oxide (a greenhouse gas), but composted manure does not.
So what does all this mean for a backyard gardener? While some question the efficacy of carbon farming, regenerative agriculture practices overall contribute to healthier ecosystems--and are practices that any backyard gardener can adopt.
Regenerative agriculture essentially combines the principles of organic farming with an overarching goal of enhanced carbon drawdown. Its practices include:
• No-till or minimum tillage (preserves fungal communities and limits carbon release)
• Application of cover crops, crop rotations, compost (increases soil health and fertility without using synthetic fertilizers)
• Building biodiversity (through planting cover crops and borders/hedges for pollinators)
I have already adopted some of these practices--and I hope that my backyard garden will do its part in returning carbon to the earth.