Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Urban 'green' spaces may contribute to global warming

Dispelling the notion that urban "green" spaces help counteract greenhouse gas emissions, new research has found -- in Southern California at least -- that mowing and other lawn maintenance emit much larger amounts of greenhouse gases than the well-tended grass sequesters.

Turfgrass lawns 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 new 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.

Previous studies have documented lawns storing carbon, but this research was the first to compare carbon sequestration to nitrous oxide and carbon dioxide emissions from lawn grooming practices.

"Lawns look great -- they're nice and green and healthy, and they're photosynthesizing a lot of organic carbon. But the carbon-storing benefits of lawns are counteracted by fuel consumption," says Amy Townsend-Small, Earth system science postdoctoral researcher at University of California, Irvine. Townsend-Small is the lead author of the study, which has been accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union (AGU).

The research results are important to greenhouse gas legislation being negotiated, Townsend-Small says. "We need this kind of carbon accounting to help reduce global warming," the lead author says.

"The current trend is to count the carbon sinks and forget about the greenhouse gas emissions, but it clearly isn't enough."

Turfgrass is increasingly widespread in urban areas and covers 1.9 percent of land in the continental U.S., making it the most common irrigated crop.

In the study, Townsend-Small and colleague Claudia Czimczik analyze grass in four parks near Irvine, Calif. Each park contains two types of turf: ornamental lawns (picnic areas) that are largely undisturbed, and athletic fields (soccer and baseball) that are trampled a lot and replanted and aerated frequently.

The researchers took and evaluated soil samples over time to ascertain carbon storage, or sequestration, and they determined nitrous oxide emissions by sampling air above the turf. Then they calculated carbon dioxide emissions resulting from fuel consumption, irrigation and fertilizer production using information about lawn upkeep from park officials and contractors.

The study shows that nitrous oxide emissions from lawns are comparable to those found in agricultural farms, which are among the largest emitters of nitrous oxide globally.

In ornamental lawns, nitrous oxide emissions from fertilization offset just 10 percent to 30 percent of carbon sequestration. But fossil fuel consumption for management, the researchers calculate, releases about four times more carbon dioxide than the plots can take up. Athletic fields fare even worse, because -- due to soil disruption by tilling and resodding -- they don't trap nearly as much carbon as ornamental grass but require the same emissions-producing care.

"It's impossible for these lawns to be net greenhouse gas sinks because too much fuel is used to maintain them," Townsend-Small concludes.

The UCI study was supported by the Kearney Foundation of Soil Science and the U.S. Department of Agriculture.

Maria-Jose Vinas | American Geophysical Union
Further information:

More articles from Studies and Analyses:

nachricht Rutgers-led innovation could spur faster, cheaper, nano-based manufacturing
14.02.2018 | Rutgers University

nachricht New study from the University of Halle: How climate change alters plant growth
12.01.2018 | Martin-Luther-Universität Halle-Wittenberg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>