Published on January 21st, 2010 | by Jennifer Lance

Urban Lawns Contribute to Climate Change

There’s a movement to green urban spaces. From seed bombs to guerrilla gardening, vigilantes are taking the green movement to a new level changing the concrete jungle landscape. In fact, studies have proven that inner city children that grow up in green neighborhoods are healthier, but do green lawns really benefit our health and planet? Not according to a University of California at Irvine study that found ornamental lawns do not sequester enough carbon to offset their care.

Photo by heipei

Lawn care contributes to climate change

Lawns are often cited negatively for their excess water needs, use of chemical fertilizers, and greenhouse gas emitting mowers; however, there has been an assumption that they are good for the environment due to carbon dioxide absorption during photosynthesis. Science Daily explains:

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.

The study focused on Southern California, but the results do have an impact on the 1.9 percent of land in the US that is covered by manicured grass. Lead author of the study Amy Townsend-Small states, “It’s impossible for these lawns to be net greenhouse gas sinks because too much fuel is used to maintain them.” This is the first study to compare “carbon sequestration to nitrous oxide and carbon dioxide emissions from lawn grooming practices”.

The results of this study are not really surprising. Abandoning green urban spaces is not the solution, but greening their maintenance would change the results of this study. If organic fertilizers and electric or manual tools were used, lawns and parks may become the carbon sinks cities desperately need.