From the AMERICAN CHEMICAL SOCIETY comes this counter-intuitive finding:
During heat waves, urban trees can increase ground-level ozone
Previous research has shown that planting trees in cities can have multiple benefits, including storing carbon, controlling storm water and cooling areas off by providing shade. This has spurred efforts in cities across the U.S. and Europe to encourage the practice. However, it’s also known that trees and other plants release volatile organic compounds, or VOCs, that can interact with other substances and contribute to air pollution. And when it’s hot, plants release higher levels of VOCs. Galina Churkina and colleagues wanted to investigate what effects heat waves and urban vegetation might have on air pollution.
The researchers compared computer models of air pollutant concentrations in the Berlin-Brandenburg metropolitan area in Germany in the summer of 2006, when there was a heat wave, and the summer of 2014, which had more typical seasonal temperatures. The simulation showed that during the summer of 2006, VOCs from urban greenery contributed to about 6 to 20 percent of the ozone formation, and that during the heat wave period, the contribution spiked to up to 60 percent. The researchers suggest that in addition to tree-planting campaigns, efforts to improve cities’ environments should include other measures such as reducing vehicular traffic, a major source of nitrogen oxides that can react with VOCs and form ozone.
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The authors acknowledge funding from E.U. COST’s GreenInUrbs project.
The paper’s abstract is here: http://pubs.acs.org/doi/abs/10.1021/acs.est.6b06514.
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You will never meet anyone in your entire life that is allergic to CO2. Countless people are allergic to pollen and get hayfever. Mother Nature is by far the greatest “polluter.” She also creates the most CO2.
Mother Nature still produces thousands of other substances against which ozone and NOX feels like milk and honey. The only problem with the whole thing is the stupidity of the people whose infinity Albert Einstein has already established.
Heat causes trees to emit more terpenes. UV light breaks down terpenes and other VOCs in the air to produce ozone. It’s all basic chemistry.
I actually do not see a problem with their research. They are simply recognizing that man is not solely responsible for the ozone pollution, which can be a big problem in cities and affects not only cities but entire regions during heat waves, and in fact, much of it is natural. No one is suggesting getting rid of, or not planting more trees; their benefits are well-known. There are no easy solutions, but we can only try to limit our own contributions. It is actually a relief to hear about actual pollution instead of fake pollution. I used to see the summer haze over our White Mountains here in New Hampshire, and felt somewhat ashamed as a human, thinking that mankind was solely responsible. Then I did read about the Smokey Mountains, and how they acquired that name.
Their results are from a computer model and presents a possibility that may or may not show reality. However, it would seem to this simple red neck that it would be easy to test that possibility if only they got out of the air conditioning and into the field.
Ozone is not the problem during heat waves.
Heat is the problem during heat waves.
The increase in premature deaths during heat waves is almost identical in low ozone areas as in high ozone areas.
Let’s start a march to Ban Mother Nature ….(do I really need to add a SARC ? )
Thank you, oh, thank you, you have just solved my winter heating problems, I will not need to use transport to heat my house, ( I live opposite the park ) so I can save the planet.
Anybody got a good used chainsaw for sale ??
Chop ’em all, and chip ’em quick!
Urban forests in Brit cities could keep Drax running for how long? Think of the savings in terms of marine-shipping-costs, concomitant fuel-oil emissions; reduced asthma deaths; increased Urban Heat Island effects (to the extent that they will offset the coming ice-age in N. Europe– thanks to global Warming — thus less freezing Grannies in blacked-out hovels, and even the Greeniacs will be happy with a treeless urban-scape.
Their “models” indicate that trees produced 6-2-% of the ozone and this went to 60% in heatwaves. But nowhere in this is any indication of the actual level and whether or not this poses any threat. You would have to go to the paper for that….
Typical scary headline with a tiny fact pulled from the paper to make a story and get some clicks. This is pure spin and doesn’t deserve any more attention, but the headline will get repeated endlessly as more “proof” that climate change is bad and we have to stop using energy now!
No tree of knowledge was harmed in the making of this study.
Yep, I saw the phrase, “computer models”, and immediately my red flags came a flyin’.
I would like to see phrases like, “strategically place monitors in such a such fashion”, “ran multiple trials of measuring at such and such times of day”, “figured averages”, etc., …. and, yeah, use the computer to tabulate the MEASURED, ACTUAL data, … and THEN tell me what you find.
Oh, and do this for areas with large numbers of trees, compared to smaller numbers of trees.
Needless to say, I find it hard to trust the conclusions, based on the methods, … and I’m not even a scientist !
“Yep, I saw the phrase, “computer models”, and immediately my red flags came a flyin’.”
Computer models
Skeptical Science has a recent post of several studies that conclude that since actual temps are less than the models, that the natural variations in temps are negative by the amount the models are overstated.
So you completely missed the part where they said that they used DATA from two events. They used the models to compare the actual events.
… two events
Is that sarcasm ? What I see is that computer models are used to estimate, rather than actually measure, certain quantities. And ONLY two events would seem to make this MODELING even less convincing.
Two events, each lasting all summer. They could not, cannot, measure in isolation the discharge from foliage. They do however have good estimates and measurements of emissions from human activity. They put the known values into the model and see what value is needed to tune the models to get values matching the many in-situ measurements that they have from various locations and at various times throughout the summer, given also the measured weather conditions.
They are using the models to calculate a mass balance.
I believe this is a recycled study. It seems that when it comes to climate rent seeking everything old is new again. So trees gather CO2, H2O and sunlight and emit various metabolites. President Reagan was ridiculed by the enviro extremists of the day for pointing this out. Greens are in it for the green: power that is.
Yes, I’m old enough to remember them ragging Reagan for saying that Smog was actually made by trees. It was one of their proofs he was not smart at all, even though he was quoting a study by one of the Cal universities.
But then, according to the same set, John Effing Kerry and AlGore were so much smarter than GWB who had higher grade point averages and could fly a jet from Texas to Florida with the canopy painted white so you could not see out.
The VOCs released depend on the plants involved and the local conditions. This should be a consideration when planning plantings.
When I started my university studies, scientists did actual measurements. They were measuring things not only in labs but also out in the real world. Now it seems science is all computer models. Put your numbers (from another model?) into your model get the result and publish them. This kind of results means absolutely nothing until confirmed with on the spot measurements and some convincing reasoning as to why this ozone has to come from the trees.