Recall a couple of days ago that I posted on the aerosols released by trees: Those dirty trees: why hasn’t the EPA called for trees to be regulated?
Now, from the International Institute for Applied Systems Analysis comes a cause-effect for climate.
Plants moderate climate warming
As temperatures warm, plants release gases that help form clouds and cool the atmosphere, according to research from IIASA and the University of Helsinki.
The new study, published in Nature Geoscience, identified a negative feedback loop in which higher temperatures lead to an increase in concentrations of natural aerosols that have a cooling effect on the atmosphere.
“Plants, by reacting to changes in temperature, also moderate these changes,” says IIASA and University of Helsinki researcher Pauli Paasonen, who led the study.
Scientists had known that some aerosols – particles that float in the atmosphere – cool the climate as they reflect sunlight and form cloud droplets, which reflect sunlight efficiently. Aerosol particles come from many sources, including human emissions. But the effect of so-called biogenic aerosol – particulate matter that originates from plants – had been less well understood. Plants release gases that, after atmospheric oxidation, tend to stick to aerosol particles, growing them into the larger-sized particles that reflect sunlight and also serve as the basis for cloud droplets. The new study showed that as temperatures warm and plants consequently release more of these gases, the concentrations of particles active in cloud formation increase.
“Everyone knows the scent of the forest,” says Ari Asmi, University of Helsinki researcher who also worked on the study. “That scent is made up of these gases.” While previous research had predicted the feedback effect, until now nobody had been able to prove its existence except for case studies limited to single sites and short time periods. The new study showed that the effect occurs over the long-term in continental size scales.
The effect of enhanced plant gas emissions on climate is small on a global scale – only countering approximately 1 percent of climate warming, the study suggested. “This does not save us from climate warming,” says Paasonen. However, he says, “Aerosol effects on climate are one of the main uncertainties in climate models. Understanding this mechanism could help us reduce those uncertainties and make the models better.”
The study also showed that the effect was much larger on a regional scale, counteracting possibly up to 30% of warming in more rural, forested areas where anthropogenic emissions of aerosols were much lower in comparison to the natural aerosols. That means that especially in places like Finland, Siberia, and Canada this feedback loop may reduce warming substantially.
The researchers collected data at 11 different sites around the world, measuring the concentrations of aerosol particles in the atmosphere, along with the concentrations of plant gases, the temperature, and reanalysis estimates for the height of the boundary layer, which turned out to be a key variable. The boundary layer refers to the layer of air closest to the Earth, in which gases and particles mix effectively. The height of that layer changes with weather. Paasonen says, “One of the reasons that this phenomenon was not discovered earlier was because these estimates for boundary layer height are very difficult to do. Only recently have the reanalysis estimates been improved to where they can be taken as representative of reality.”
Reference
Paasonen, P., et. al. 2013. Evidence for negative climate feedback: warming increases aerosol number concentrations. Nature Geoscience doi: 10.1038/NGEO1800
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An interesting question is whether all plants emit the same amount of aerosols per hectare and are they of equal effectiveness. So, for example, when in response to warmist hysteria, the rain forests are replaced with sugar cane or oil seed palms for the production of bio fuels does this increase or decrease the warming/cooling response. i.e. are the warmists in fact really warmists contributing directly to warming via their insane bio-fuel projects.
Jimbo Says.
“Mosher is not a scientist ”
Which does explain the basic lack of scientific understanding inherent in the large majority of his posts.
This is just another desperate attempt on the Climate Fictionists’ part to stay in business. Aeorosols, whether manmade or natural give them an “out”, and wiggle room (or so they think). The warming is still there, you see, it’s just being hidden by all these other factors, so we just need to add these other factors back into the models to make them better. Riiiiight.
Jimbo quotes… “Additionally, [b]temperature increases and warming-induced change are progressing faster than had been predicted in some regions[/b]”
Clearly talking about the ocean under 700m there!
hmm, HTML fail :p
Rob:
Please cite your evidence for your astonishing assertion concerning “the ocean under 700m” that ” temperature increases and warming-induced change are progressing faster than had been predicted”.
Richard
Did someone mention koolaid? This “study” is a good example. They take their standard, sour C02-centric climate formula, add a good helping of sweetness in the form of actual science to make it go down easier, and presto! Whoever mentioned koolaid above didn’t seem to understand how it’s made, so I’m happy to help him out.
The contribution of aerosols to climate forcings is guesswork. Known is, however, that trees are the largest source of methane to the atmosphere [Pangala et al., New Phytol. 197: 524-531, 2013] . Rising atmospheric methane concentration correlates with global warming even more than carbon dioxide [Reay et al. in “Methane and climate change”, Earthscan, 2010]. Hence, scientific consensus on arborgenic global warming (AGW) calls for immediate large-scale lumbering. Save nature: cut down the trees !
Over land dust is king. Over the oceans salt and organic compounds are king. Of greater importance, wind appears to be the driver of changes in these major sources of aerosols and the climate community laments they can’t get their models to reproduce the wind (or clouds, or El Nino events, or La Nina events, or no ninoa events or…etc, etc, etc). Do you suppose this is why they try to compensate by producing their own wind? Gas from plant flatulence has to be a new low in investigating the minutia of the h-air on a gnat’s ass.
This is completely OT and absolutely not meant for posting but where else is there to say this : I am having trouble getting on to and around in WUWT. Is it my computer or have others been having trouble?
I hit the WUWT website and get a strip ad at the top of the page, so I hit Refresh and get another ad, Refresh again and perhaps I get in or perhaps another ad ( 6 is the record so far). Then I get the first item and nothing else. So the whole thing starts again. Eventually I get the listed articles and choose one to read and hit either the title or Continue reading and get more ad/refresh, ad/refresh until I can read the article but no comments. This has started very recently, in the last 9 days, and is frustrating and time-consuming. Is this just me?
You can actually see this in action. Drive along I-8 in southern California. You will notice a drop in the temperature between the east and west Canals (where they irrigate the land to farm).
Has anyone mentioned that CO2 causes Global cooling because it was figured that it has a negative feed back? LMAO!!
No mention of terpenes, any where.
phlogiston asks (at April 28, 2013, 3:32 pm above) about how much area is required to keep a person alive. The UN’s Food and Agricultural Organization calculated in 1993 that it was as little as 0.17 acre per person. But that is under ideal conditions (no land degredation, water shortages, post-harvest waste, human errors by the farmer in planting times, crop choices, etc) and it assumes a subsistence diet.
Dr David Pimentel of Cornell more reasonably calculated that to support one person on a diverse Western diet requires just over 1 acre of “average” land.
Interestingly, you can support more people on a given unit of land by adding meat to their diet because the animals are able to exploit land which is unsuitable for cultivated crops. But it has to be the right kind of meat. Grazers like beef are good for land usage. Grain-fed animals like poultry work against you on the person/acre basis.
Jimbo was highlighting the amazing claim of the study’s preamble that CO2 warming has proceeded at unexpectedly high rates in some regions, I joked that the “regions” they meant must have been <700m in the ocean because based on surface temp, that's crazy talk.
I thought everyone knew that Mosher is an English major with a career in marketing?
Steven Mosher, B.A. Philosophy and English, Northwestern University (1981); Director of Operations Research/Foreign Military Sales & Marketing, Northrop Aircraft Northrop Aircraft (1985-1990); Vice President of “Engineering” [Marketing], Eidetics International (1990-1993); Director of Marketing, Kubota Graphics Company (1993-1994); Vice President of Sales & Marketing, Criterion Software (1994-1995); Vice President of Emerging Technology [Marketing], Creative Labs (1995-2006); Vice President [Marketing], Openmoko (2007-2009); Marketing Consultant, Qi Hardware Inc. (2009); Marketing Consultant (2010-Present); [Marketing] Advisor, RedZu Online Dating Service (2012-Present)