An average quality lawn captures how many times the carbon output of a typical gasoline-powered mower?

An average quality lawn captures how many times the carbon output of a typical gasoline-powered mower?

• A. 2
• B. 3
• C. 4
• D. 5

Answer: (C)

This question tests how turfgrass can act as a carbon sink compared to the emissions from mowing. Grass captures carbon through photosynthesis, turning CO2 into plant biomass and, importantly, storing carbon in the soil through roots and organic matter. When clippings are left to decompose, that carbon is returned to and built up in the soil, boosting soil organic carbon over time. On the other hand, a gasoline mower releases CO2 and other greenhouse gases as it burns fuel, adding to annual emissions. In an average-quality lawn under typical management, the amount of carbon the grass and soil accumulate over a season can surpass the mower’s annual emissions by several times. Four times is a reasonable, representative estimate under common conditions, because the continual growth and soil carbon storage from a healthy lawn often outpace the single source of emissions from mowing. Of course, the exact ratio varies with mowing frequency, lawn health, soil type, and whether clippings are returned to the lawn.

This question tests how turfgrass can act as a carbon sink compared to the emissions from mowing. Grass captures carbon through photosynthesis, turning CO2 into plant biomass and, importantly, storing carbon in the soil through roots and organic matter. When clippings are left to decompose, that carbon is returned to and built up in the soil, boosting soil organic carbon over time. On the other hand, a gasoline mower releases CO2 and other greenhouse gases as it burns fuel, adding to annual emissions.

In an average-quality lawn under typical management, the amount of carbon the grass and soil accumulate over a season can surpass the mower’s annual emissions by several times. Four times is a reasonable, representative estimate under common conditions, because the continual growth and soil carbon storage from a healthy lawn often outpace the single source of emissions from mowing. Of course, the exact ratio varies with mowing frequency, lawn health, soil type, and whether clippings are returned to the lawn.