According to UC Irvine researcher Amy Townsend-Small, just because grass is green doesn't mean it's 'green'. New research has shown that the fertilizers and other carbon emissions produced in the maintenance of turfgrass actually emit more greenhouse gasses than are processed through the grass by photosynthesis.
"Turfgrass lawns help remove carbon dioxide from the atmosphere through photosynthesis and store it as organic carbon in soil, making them important “carbon sinks.” However, greenhouse gas emissions from fertilizer production, mowing, leaf blowing and other lawn management practices are four times greater than the amount of carbon stored by ornamental grass in parks, a UC Irvine study shows. These emissions include nitrous oxide released from soil after fertilization. Nitrous oxide is a greenhouse gas that’s 300 times more powerful than carbon dioxide, the Earth’s most problematic climate warmer."