From the American Chemical Society
Green plants reduce city street pollution up to 8 times more than previously believed
Trees, bushes and other greenery growing in the concrete-and-glass canyons of cities can reduce levels of two of the most worrisome air pollutants by eight times more than previously believed, a new study has found. A report on the research appears in the ACS journal Environmental Science & Technology.
Thomas Pugh and colleagues explain that concentrations of nitrogen dioxide (NO2) and microscopic particulate matter (PM) — both of which can be harmful to human health — exceed safe levels on the streets of many cities. Past research suggested that trees and other green plants can improve urban air quality by removing those pollutants from the air. However, the improvement seemed to be small, a reduction of less than 5 percent.
The new study sought a better understanding of the effects of green plants in the sometimes stagnant air of city streets, which the authors term “urban canyons.”
The study concluded that judicious placement of grass, climbing ivy and other plants in urban canyons can reduce the concentration at street level of NO2 by as much as 40 percent and PM by 60 percent, much more than previously believed. The authors even suggest building plant-covered “green billboards” in these urban canyons to increase the amount of foliage. Trees were also shown to be effective, but only if care is taken to avoid trapping pollutants beneath their crowns.
The authors acknowledge funding from the UK Engineering and Physical Sciences Research Council Sustainable Urban Environment program.
The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 164,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
When I was young the streets of London where I lived were full of big trees. Later they cut them all down to save on maintenance costs.
This study has been funded by the No Shit, Sherlock Foundation.
Everything nowadays is more, or less than “previously thought”.
Since they are so thought-less, how could there be a concensus?
We have here an unprecedented opportunity.
I will be happy to provide any leftist city with all the green plants they want.
Kudzu.
I THINK that I shall never see
A Mann lovely as a tree.
A Mann whose hungry mouth is prest
Against the Goverment funding flowing breast;
A Mann that thinks he’s God all day,
And lifts his beafy arms to bray;
A Mann that may in summer wear
A drought or heat wave with which to swear
Upon whose word this totally due,
To CO2, Oh boo, oh Hoo!
Men are mocked by fools like me,
But only Mann can read a tree.
Apologies to Kilmore…
@johnmcguire
I thought the value of the cambered road was to collect water and direct it to the roadside, where indeed plants can grow well.
“The new study sought a better understanding of the effects of green plants in the sometimes stagnant air of city streets, which the authors term “urban canyons”
http://architecture.mit.edu/class/nature/student_projects/2009/jcalamia/Frame/05_canyonwind.html
http://www.yorku.ca/anderson/geog3040%20f10/wind_files/frame.htm
•Woman blown over at Bay & King, 26 Jan 1978
http://www.yorku.ca/anderson/geog3040%20f10/wind_files/slide0034_image031.jpg
Max Hugoson says:
July 21, 2012 at 2:09 pm
You should be apologetic, Max (and it’s “Kilmer” not “Kilmore”), but more to the point, you accurately display the vast polar difference between God’s gift to man and Mann’s gift to himself.
Mann’s the “Kilmore”
Are we sure we want trees? Because CO2 levels could drop in our already CO2 starved atmosphere…
And in Australia, part of the opposition’s “direct action plan” involves planting lots of trees.
The AGW bletheren don’t like that idea because it won’t destroy Australian industry like the carbon tax will.
Its amazing how often, when trying to talk to the warmists over here about the carbon tax, the very first thing they do is say “what about Mr Abbott’s direct action plan?” DOH !!!
Even if there wasn’t a CO2 scare scam running, we should always be planting more trees now that we have released some of the long buried carbon and put it back in the atmosphere where it belongs. Lets get the Earth flourishing and fertile again !!
PLANTS LUV CO2 !!!
pjssjr says:
“Are we sure we want trees? Because CO2 levels could drop in our already CO2 starved atmosphere…”
That’s why we HAVE to keep releasing lots of CO2, to maintain the balance between the increasing world biomass and CO2.. It is obvious that around 280ppm is the basic subsistence balance level (that has been, apparently, the pretty constant level of many many thousands of years)
We MUST maintain it at a much higher level if plant life is to flourish.
ps: “Towards 700ppm”
Hi DIrkH,
Not all trees & plants put out isoprenes (C5H8); for example Birch trees do not while Poplar trees do. (? Didn’t the N.E. USA cities have a Birch tree crisis a few decades ago ?)
One of the plant’s isoprenes benefits is, among other things, to protect what envelops the chloroplast & conveniently it is near chloroplasts that isoprenes are made.
Counter-intuitively, in city air with lots of ozone those trees making isoprenes actually take up more ozone (than compared to when that same type of isoprene producing tree is in an environment of low ozone , like far or not down wind from a city). The tree isoprenes apparently act like an anti-oxidant; so that despite the extra O3 in their leaves those isoprene making trees still suffer less oxidative damage within their leaves’ “humid” mesophyllic layers.
My current ‘life’s work’ … http://pindanpost.com/2012/07/22/greening-urban-streets/ Thanks for the post Anthony, makes it all look worthwhile.
Urban planners of the 18th and 19th century included trees and parks as part of the cities which they designed. (vis e.g. Berlin and Paris) For eactly the reason that they understood the improvement in air quality. The understood that from observations.
While trees and other plants won’t filter all types of nasty emissions, they do pretty well on most. And that is a good, effective and affordable way of tackling those emissions. The transpiration from trees also helps to moderate peak temperatures in the urban heat island.
Trees
by Joyce Kilmer
That is an excruciatingly bad poem. What would be your reaction if the author had become so poetically aroused over a puppy or a bunny rabbit?
I am reminded of the work of Jessica Wood McKeand of Laguna Beach. After her death the Laguna Poets sought to collect and destroy every copy of her chapbook in existence. i possess one of the few remaining extant.
The chapbook is called “Sunshine And Shadows” (1970) and is dedicated to her recently deceased little blonde cocker named Buckles. The majority of the poems are about Buckles but she does toss in a few about her son who had also recently died of cancer. Below are some excepts from her work.
His faithful little tail
Never ceased to wag
I used to think
How tired, it must get!
—————————-
He knew no guile, as humans do,
No jealousy, nor hate
A kind, and loving spirit —
And Oh! How patiently he’d wait!
—————————-
Dear,dear little Buckle’s last, and most precious token of devotion, was the night before he died, when, during the night he crawled with supreme difficulty, and super-humane effort, having to drag his dear paralyzed, and helpless back legs, in order to get just as close to my bed, and as near to me, as he possibly could — giving me as always, his last full measure of devotion …..to be next to me in what I believe he knew,was near the end. His love and devotion, were far greater than any human love. I will always know, he had a touch of the DIVINE!
———————————-
I know that love never dies.
Love is Eternal.
And i know that your beautiful soul, lives on, little Buckles.
God would not deny you this.
—————————————-
One day, while gazing into your beautiful, soul-searching eyes, a friend said, “Oh Buckles, you must know something we do not know, because you are SO BEAUTIFUL!
———————————–
Part of the joy of reading McKeand is trying to figure out where her poetic ideas came from. You may recognize the source for this —
There is the beauty of the trees, giving shelter
With their arms outstretched to their God.
Eugene WR Gallun
interesting post, gringojay, but I think you meant anthropogenic CO2 in your last line.
London is perhaps the greenest city in Europe with many large and small parks and roadside trees. The City of London, without much in the way if greenery, has poor air quality compared to the rest of the city. Despite the PM2.5 from diesels engined vehicles the air is breathable.
I fully endorse Tim Ball’s recommendation of http://www.co2.org. Good site with reports of real CO2 science.
Urederra thanks for catching the big “C” I omitted above & giving me the benefit of the doubt I hadn’t just captured that carbon & traded it!
As to why NO2 is cleared so much more than anticipated consider my surmise. High CO2’s inorganic carbon (C) processing done by trees/plants drives carboxylation in the plant cell’s carboxysome’s photosynthetic Rubisco makes 3-phospho-glycerate which is processed into glycer-aldehyde 3-phosphate.
Glycer-aldehyde 3-phosphate is used to do several things inside the plant besides just cobbled together into chains of 6 carbon carbohydrate molecules. The portion that is shunted through the plant cell’s Krebs pathway spins off alpha keto-glutarate which forms up into something like the backbone of a carbon skeleton which is a scaffold for tying nitrogen (N) atoms to. This is where the NO2 absorbed unloads it’s N ; and so, the more C uptake the more scaffolds to assimilate N giving room for more NO2 to be cleared from the air.
If/when CO2 too low then inside the leaf there is not the ideal concentration of CO2 to drive carboxylation. So then in order to make the inorganic carbon taken in into the plant’s own organic carbon there’s a default reaction. Oxidation, as opposed to carboxylation, gives that leaf only 2-phospho-glycollate & this is a 2 carbon chain molecule. But this molecule isn’t made downstream into a scaffold for assimilation of N atoms. Then the plant must expend energy stores to perform photo-respiration in order to process those 2 carbon chain molecules.
Anthropogenic NO2 & anthropogenic CO2 apparently have a standing date in city tree leaves.
Steve in SC says:
July 21, 2012 at 1:48 pm
We have here an unprecedented opportunity.
I will be happy to provide any leftist city with all the green plants they want.
Kudzu.
________________________________
Don’t forget the $%#$@ur momisugly# Johnson grass. I am still fighting the blasted stuff. Just introduce it to all the city parks (snicker)
polistra says:
July 21, 2012 at 12:59 pm
Also need to bear in mind that trees won’t survive every type of pollution. Back in the ’70s a lead smelter near Blackwell was trying to clean its reputation without cleaning its output, and planted a long avenue of poplars along the side of its facilities. The trees turned gray, bent over and died within a year, leaving a dramatic demonstration of the pollution instead of a covering shield of green.
_________________________
Zinc smelter, as I recall- Blackwell, OK, USA
“The study concluded that judicious placement of grass, climbing ivy and other plants in urban canyons can reduce the concentration at street level…”
So it’s not just about trees. Here in Ontario, Canada it is becoming increasingly difficult to maintain a green lawn, mostly because the eco-extremists have banned the use of what they call “cosmetic” herbicides and pesticides. As a result lawns are being destroyed by weeds and grubs, and some people are even switching to some kind of ornamental rocks and gravel (although I’m sure it has a more appealing name) instead.
Ouch Gail Combs,
Johnsongrass is also a leafhopper Graminella Nigrifrons host. This bug is carrying maize fine streak nucleo-rhabdo-virus (MFSV) leading to stunted/chlorotic corn plants, in addition to being an insect vector of both corn stunt spiroplasma & maize bushy stunt phytoplasma pathogens. That leafhopper must ingest MFSV from a contaminated plant in order to spread it to maize/corn.
One of the under reported effects of elevating CO2 on plant leaves is their relatively reduced nitrogen content leads to proportionately more leaf munching by bugs in attempt to compensate for lower nitrogen amount per bite. So, outside of a greenhouse where plants are exposed to lots of insects there is more herbivore bug feeding being done on the CO2 boosted plant. If the Johnsongrass host leaves are getting even more chewed on by leafhoppers they then go over & chew even more on nearby food crop leaves
Look how the interplay becomes more variable; although I am no longer discussing plant pathogens or their resolution. Jasmonic acid is plants first (but not only ) line of defense against munching insects. WIthin most genetic types of plants the physical contact with a herbivore bug causes that plant to up-regulate it’s output of jasmonic acid. But experiments with higher than contemporary CO2 show some genetic variations of some plants are not able to boost protective jasmonic acid in response to chewing insects and some actually put out less jasmonic acid when bug chews it.
The impracticality of eradicating Johnsongrass points to agriculture’s best hope lying in genetic manipulation to introduce more jasmonic acid genes into food crops. This would carry over in a general sense to provide additional plant resistance against chewing bug attacks anticipated to be more active as CO2 rises. Humans have been breeding plants for a long time so probably some of that resulted in improved jasmonic acid genetics as evidenced in specific seed strains local farmers say they plant because “local” bugs leave it alone enough to harvest a worthwhile yield. Pardon the digression I’ve indulged in.
This will be great for the environment. More needs to be done to combat the problems of climate change. Affirmative action is what is required.
gringojay says:
July 22, 2012 at 5:55 pm
Ouch Gail Combs,
Johnsongrass is also a leafhopper Graminella Nigrifrons host. ….
__________________________
I have found the easiest way to kill Johnsongrass is to confine my goats in the patch and let them eat it and stomp it to death. Unlike horses goats do not pass viable seed in their feces. Round-up only seems to kill the stems and the stuff comes back a few months later or the next year either from seeds or the rhizomes.
One of the problems with studies like this is the politicians go off half-cocked and do stupid things like intentionally planting Kudzu or Johnsongrass or Kentucky 31 Fescue (another grass with problems – abortion in pregnant herbevoires)
Johnsongrass because of its extensive rhizome system is considered a valuable species for erosion control and use to be planted in road side gullies. see FAO