Now according to this press release from UC Irvine, green spaces in cities are bad for the planet….but wait, what about the UHI offset? Can I buy grass credit certificates?
Urban ‘green’ spaces may contribute to global warming, UCI study finds
Turfgrass management creates more greenhouse gas than plants remove from atmosphere
— Irvine, Calif., January 19, 2010 —
Dispelling the notion that urban “green” spaces help counteract greenhouse gas emissions, new research has found – in Southern California at least – that total emissions would be lower if lawns did not exist.
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.
“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,” said Amy Townsend-Small, Earth system science postdoctoral researcher and lead author of the study, forthcoming in the journal Geophysical Research Letters.
The research results are important to greenhouse gas legislation being negotiated. “We need this kind of carbon accounting to help reduce global warming,” Townsend-Small said. “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 analyzed grass in four parks near Irvine, Calif. Each park contained two types of turf: ornamental lawns (picnic areas) that are largely undisturbed, and athletic fields (soccer and baseball) that are trampled and replanted and aerated frequently.
The researchers 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 showed that nitrous oxide emissions from lawns were 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 calculated, released about four times more carbon dioxide than the plots could take up. Athletic fields fared even worse, because – due to soil disruption by tilling and resodding – they didn’t trap nearly as much carbon as ornamental grass but required 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 concluded.
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.
The UCI study was supported by the Kearney Foundation of Soil Science and the U.S. Department of Agriculture.
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What we need are more lawns, and an environmentally friendly way of maintaining them.
I suppose rows of Green Party members on their hands and knees cutting the grass with their teeth would be unacceptable?
Sorry, sorry. Just an idea. Bad idea.
Carry on.
The referenced study claims: “The study showed that nitrous oxide emissions from lawns were comparable to those found in agricultural farms, which are among the largest emitters of nitrous oxide globally.”
I noted today at CO2Science that ongoing research at Duke U’s experimental forest that studied the effects on loblolly pine from elevated CO2 levels over 12 years is contrary to some of the findings in the Cal Irvine study. See:
http://www.co2science.org/articles/V13/N3/B2.php
“What was learned
Among many other things, Jackson et al. report that “on average, in elevated CO2, fine-root biomass in the top 15 cm of soil increased by 24%,” and that in recent years the fine-root biomass increase “grew stronger, averaging ~30% at high CO2,” while in terms of coarse roots having diameters greater than 2 mm and extending to a soil depth of 32 cm, they report that “biomass sampled in 2008 was “twice as great in elevated CO2.” In fact, we calculate from the graphical representation of their results that the coarse-root biomass was fully 130% greater, which is really astounding, particularly in light of the fact that the extra 200 ppm of CO2 supplied to the air surrounding the CO2-enriched trees represented an enhancement of only about 55% above ambient conditions. And in the concluding sentence of their paper’s abstract, they say that “overall, the effect of elevated CO2 belowground shows no sign of diminishing.”
“What it means
The four researchers state that “if progressive nitrogen limitation were occurring in this system, we would expect differences in productivity to diminish for trees in the elevated vs. ambient CO2 plots,” but they say that “in fact there is little evidence from estimates of aboveground or total net primary productivity in the replicated Duke experiment that progressive nitrogen limitation is occurring there or at other forest FACE experiments [italics added],” even “after more than a decade of manipulation” of the air’s CO2 content, citing in this regard — with respect to the latter portion of their statement — the report of Finzi et al. (2007). Consequently, there is good reason to believe that the “aerial fertilization effect” of atmospheric CO2 enrichment will continue to significantly benefit earth’s forests for as long as the atmosphere’s CO2 concentration continues to rise.”
I hope the Cal Irvine researchers are advised about the contradictory research at Duke.
Jon (10:02:15) :
Trees devour carbon dioxide and spew out oxygen. The re-growth of forests in Eastern US is looked at as the reason North America is a carbon sink with less CO2 leaving the US than entering it.
This obviously cannot be true, else how could the USA be labeled as the second-worst CO2 “polluter” in the world? If the Eastern US forests are absorbing CO2 being spewed elsewhere in the world, it is we who should be demanding money from other countries for taking care of their carbon emissions, not the other way around!
Wayne Delbeke (09:44:30) :
“Using a one million sq. km stretch of forest in Manitoba, Gower and his colleagues coupled their measurements of how carbon moved between the atmosphere and the trees with past records and computer models to examine how the forest’s ability to store carbon dioxide has changed since mid-century. Their results showed that the forest’s ability to store more carbon dioxide than it emitted had weakened over the last few years – to the point where it has now become a net emitter of carbon.”
Unfortunately Wayne you argument falls because the issue isn’t tropical vs temperate, but young vs old. The reference you cite is referring to mature forests and calculating the methane emissions at 40x the “global warming effect” of CO2. The forest was a massive carbon sink while it was growing (replacing the trees that were heavily logged in the previous century). This is the exactly the same deal with tropical forests – mature forests are rarely a carbon sink as growth rates are slow and dead trees are great for biodiversity, but release a lot of carbon as methane.
North America had gone through a massive re-forestation in the last 100 years or so that is coming to an end as logging is not the industry it once was. The best way to increase the role of forests as carbon sinks (always supposing that that is what you want to do, of course) is to cut the trees down and use the wood for something useful.
A commenter earlier in the thread mentioned government paperwork as a carbon sink – not sure I would class this as useful, but go ahead and see if you can get a carbon credit for it somewhere…. 😉
Does that mean I can put my lawn mower away permanently and just let my lawn evolve naturally?
Would my neighbors stand for it?
How about just plant more trees?
PeteG
brc
Dont let them know that the way you mow your lawn constitutes a workout.
They will want to tax the extra carbon dioxide that you breathe out.
”
The “camel is sticking its nose into the tent.” He says he just wants the grass but he is looking at your wheat and your cattle.
Embrace handmade cave homes and fight the war on cowfart!
That gosh darn grass producing that annoying oxygen – We can’t have any of that.
Mike R thanks for your reply but I don’t think that really answers my question. Let me try to rephrase it. We assume that for the earth’s temperature to be stable the incoming energy from the sun must must be equal to the sum of the reflected sunlight plus the emitted infra-red heat energy. Basically it means “energy in” must equal “energy out”. That’s a statement of the first law of thermodynamics in steady state conditions. In non-steady state conditions, if more energy is coming in than leaving the earth will gain energy and presumably warm up. If more energy is leaving than coming in then the earth will lose energy and cool. But that assumes that the energy can only be stored as heat. Through photosynthesis sunlight is converted to chemical energy rather than heat. In that case more energy can be coming in than leaving without producing warming. The earth would still be gaining energy but not heat energy. Given the amount of green growing plants on the planet I wonder whether that effect could produce a measurable difference in the earth’s energy balance.
Let me get this straight… If we eliminate grass, do away with cows and other ruminants, stop eating meat (except for our pets), live off of intermittent power sources, eliminate air travel, get rid of our cars, abolish industry, and ration all life necessities, we’ll have a better world?
My best analysis is the people who think in this utopia fictive reality need medication. This whole “save the planet from CO2” thing is getting a bit to bizarre to be remotely considered as rational thinking. It is becoming a form of socially accepted insanity.
Has anyone been on one of the modern turf soccer and football fields on a sunny day? They get HOT. In fact, the one at the nearby high school loses snow cover before anything around it, including the black all-weather track.
Coach: “Which do you prefer, grass or astroturf?
Lineback: “I dunno coach, I never tried to smoke astroturf”
This must also be true for biodiesel from corn. The last I heard it takes 0.9 gallons of fossil fuel oil to produce one gallon of biodiesel. If one adds the CO2, methane and nitrous oxide produced as the plant residue is composted or decomposes then it is likely to be a net emitter of GHGs.
Not sure about ethanol : there is an old paper which proved ethanol needed more energy in its’ creation than it could give in its’ use, in fact I believe it was 40% more. This gets some greens really hot and bothered and they strongly claim 35% more energy is produced from ethanol than is needed to create it, but I do not know how thorough they were in their calculations.
In both cases the problem is that FOOD is being turned in to fuel! Either the world has no problem without that food, or the food will need to be produced by farming more acres, and most likely on less productive land, which may require more fertiliser, etc.
[Another alternative is that people die. In fact it has been suggested that the real purpose of large scale biofuel production IS to control the world’s population by reducing food levels. At least that makes more sense than as a rather dubious AGW counter-measure]
Slippery slope!
It would be interesting if the same researchers did the same research for biofuel production.
“kadaka (10:49:17) :
Jon (10:02:15) :
Trees devour carbon dioxide and spew out oxygen. The re-growth of forests in Eastern US is looked at as the reason North America is a carbon sink with less CO2 leaving the US than entering it.
This obviously cannot be true, else how could the USA be labeled as the second-worst CO2 “polluter” in the world? If the Eastern US forests are absorbing CO2 being spewed elsewhere in the world, it is we who should be demanding money from other countries for taking care of their carbon emissions, not the other way around!”
I assume sarcasm as my statement is exactly correct.
They say that a cow expels more methane from its mouth than from its rear end.
Much like the average Warmist.
What the hell! Let’s have a World War! The nuclear winter should cool things down AND remove the ‘A’ from AGW! Problem solved!
Does a cow release more GHG than the yearly die down and decay of the grass that is not eaten? What does that grass decay to?
Since fertilizer releases nitrous oxides which is claimed to be 300 times worse than CO2, we need to find something else to increase plant growth. We need something that won’t run off and pollute the water. Something that is cheap and non toxic. A totally benign material. Something that can be added to the atmosphere so we don’t need to use fossil fuels to deliver it to the plants.
I suggest we use carbon dioxide.
Does any know if we could make astroturf from old IPCC reports and the many pages of worthless prose written in support of AGW?
What would happen if they used a no/low maintenance type grass like the Eco Lawn available from Wildflower Farms?
Look out methane on the rise.
NIWA has today released measurements from its globally significant Baring Head station showing that southern hemisphere atmospheric methane increased by 0.7% over the two-year period 2007–08. While this increase may not sound like much, it is about 35 times more than all the methane produced by New Zealand livestock each year.
than the same mass of carbon dioxide (CO2 ).
“The evidence we have shows that methane in the atmosphere is now more than double what it ever was during the 800,000 years before 1700AD” says NIWA Principal Scientist, Dr Keith Lassey. This is based on analyses of ancient air trapped in polar ice that has been extracted and dated.
Other factors are at work in increasing atmospheric methane levels: global growth in commercial livestock farming, mining of fossil fuels, leaks from urban gas networks, and continued burn-offs of tropical rainforest
http://www.niwa.co.nz/news-and-publications/news/all/niwa-sayes-greenhouse-gas-methane-is-on-the-rise-again
In my local council area, if you don’t mow your grass the council (which promotes the usual green ideas), will send you a letter demanding it be cut, or they’ll cut it for you and send you the bill. I know; it happened to me. I was just being lazy, not “green”!
This story finally made it onto Yahoo.
http://news.yahoo.com/s/livescience/lawnsmaycontributetoglobalwarming