For more than a century, we have been using the Earth’s atmosphere as a dumping site for carbon. Every action we take, from heating & cooling our homes to turning on the lights to driving cars to taking the train to the way we manage our yards are either continuing to dump carbon into the atmosphere or eliminating it. If you have ever calculated your carbon footprint, you know that most suggestions about reducing your carbon footprint comes from doing things less like driving less, or having your lights on less. Or, it’s about changing something like using efficient light bulbs or buying a hybrid car. With your yard, the goal is to actually do more of the good stuff like have more flowers, better grass and healthier soil.
By the Numbers
Your climate change champion status boils down to math. It’s carbon out to carbon in. Here’s the numbers: one acre of turfgrass (that is, the normal kind of grass everyone has in their yards) can remove about half a ton of carbon from the atmosphere every year. That’s not bad. It’s equal to around 53 gallons of gasoline. If you replace your turfgrass with tall perennial grasses and wildflowers, you can remove nearly four times as much carbon from the atmosphere every year (on average, according to a study by State of Minnesota).
Adding trees to your yard will also amp up your ability to drawdown your carbon footprint. A few as 9 silver maples can sequester over 2 tons of carbon each year. With long-living trees, the carbon captured is captured for decades, and potentially near a century. Pines, spruce, oak and dogwood are also good options for carbon storage.
The Other Side of the Equation
There is a downside to this however. For every ton of emissions you eliminate by growing trees, shrubs, wildflowers and perennials, you can completely neutralize it with how you maintain your yard. For example if you use gasoline powered lawnmowers to mow your grass, you are emitting about .08 tons of carbon per acre per year. If you irrigate your lawn, you are emitting about .01 lbs of CO2 of carbon per gallon of water. Those emissions come from the pumps and other mechanical devices needed to get water from its natural source to your sprinkler. Many sprinklers use about 12 gallons per minute. So if you run your irrigation system for 30 minutes, you are emitting about 3.6 lbs of carbon. This seems small, but it adds up fast. You need about 27,154 gallons of water to irrigate one acre of turfgrass with inch of water. That means 271 lbs of carbon is emitted for one watering. If you do that every week from April to Oct, you will emit over 3 tons of carbon from just keeping your lawn wet.
Fertilizers Equal Carbon
The last place you can put carbon back into the atmosphere is with chemical treatments to your yard. This is also were it gets kinda tricky. Artificial fertilizers wreak havoc on the health of your soil. As the quality of your soil degrades, so to does its ability to capture carbon. Synthetic fertilizers can hamper CO2 storage in your soil by as much as 28%.
If you want to find out more about carbon and your yard, you should check out the re:yard standards developed by MAPSOMIL’s green team. In the guide, you’ll find an entire suite of formulas that walk you through calculating your yard’s carbon footprint and more. You might also consider registering with the re:YARD program and discover what level of sustainable your yard is.