Wednesday, April 3, 2019

Playing with Fire

These scenes are from the Romanian Orthodox version of Burning Man
Humans love to play with fire.  It yields so many benefits, what's not to like?  Cooked food, heat, light, insanely rapid transportation - and back in the good old days, predator deterrence.

As medical researchers are discovering however, smoke particulates are extremely dangerous to human lungs, and can pass into the bloodstream to wreak havoc in organs throughout the body.  Injury passes through the placenta, and permanently adversely affects the young, who are still developing.  Persistent damage extends all the way from impaired cognitive ability in children to Alzheimer's in the aged.

It seems quite likely that transitioning from open wood and coal fireplaces to modern heaters in homes played a significant role on the increased life expectancy, particularly among infants, that has occurred in developed nations.  

Though it is becoming more widely recognized that pollution underlies premature mortality and widespread chronic disease in humans, there remains almost no interest in what that same pernicious toxicity means for mammal species, insects, birds, amphibians - and forests - despite ubiquitous reports of biodiversity loss and tree decline all over the globe.  These losses are found irrespective of localized weather, temperatures, habitat encroachment or pesticide use.

The World Meteorological Organization has, however, managed to sneak a few hints into its newly released report on the "State of the Global Climate". Since this blog is maintained (sort of) by an unabashed Ozonista, we'll skip everything else to zero in on what they say about ozone, starting on page 36, under the subtitle Air pollution and climate change.  Following are excerpts, with yellow highlighting references to the impact of ozone on "ecosystems" or "the environment" by which they mean damage to trees, plants, and agriculture - and also on their accurate observation that climate change studies rarely take into account the feedback of pollution on temperature, extreme weather, and the production of yet more ozone. The section also points out a longtime complaint, that advocates of biofuels as "green" sources of energy neglect to include their significant increase in ozone precursor formation.

Although climate change and air pollution are closely connected, these two environmental challenges are still viewed as separate issues and dealt with by different science communities and within different policy frameworks. However, it is not possible to separate the anthropogenic emissions into two distinct categories – atmospheric pollutants and climate-active species – as many air pollutants, such as tropospheric ozone or aerosol, have direct or indirect impacts on climate. Air pollution itself has detrimental effects on human health and the environment (see following figure). According to a report by WHO,1 over 90% of the urban population of the world breathes air containing levels of outdoor air pollutants that exceed WHO guidelines. Air pollution inside and outside the home is the second leading cause of death from non-communicable disease worldwide.

Air quality and climate change are not only driven by common constituents, they are also closely interlinked through diverse atmospheric processes. The second figure, below, depicts the complexity of these interactions.

The effects, both direct and indirect, of air quality on climate change are related to the interactions of atmospheric pollutants with solar radiation. The global average radiative forcing of ozone is similar to that of CH4, and about one quarter of that due to CO2. Tropospheric ozone negatively affects ecosystems and reduces their capacity to absorb CO2. Another indirect impact of ozone on radiative forcing has the opposite effect: production of the hydroxyl radical increases with increasing ozone concentration, shortening the lifetime of CH4 in the atmosphere. Particulate matter, which has adverse effects on human health, has both direct and indirect influences on radiative forcing. Depending on its composition, it can scatter or absorb incoming radiation directly, but particles can also act as cloud condensation nuclei and thereby affect radiative forcing and weather patterns indirectly. Deposition of the particles on snow and ice changes their albedo.

Climate change also affects air quality through changes in meteorology (including temperature, precipitations, boundary-layer dynamics, humidity and cloud cover) and through the impact it has on natural emissions. Increasing temperatures lead to increasing emissions of volatile organic compounds that are the precursors of tropospheric ozone and aerosols. Higher temperatures are also favourable for faster ozone formation. As the climate changes, ozone in peak episodes is expected to increase – the so-called “climate penalty”. Climate change is also associated with changing transport patterns and mixing and can lead to more frequent extreme pollution events due to stagnation. Changes in wildfire frequencies could lead to increasing levels of pollution, particularly aerosols. Changing precipitation patterns affect the deposition of pollutants.

Despite a growing recognition of the strong links between the two areas, policies addressing air pollution and those focusing on climate change remain weakly linked. The major challenge is to identify policies that provide “win–win” solutions, as not all climate policies are beneficial for air pollution reductions and vice versa. One example is the use of biofuels that leads to a reduction of CO2 but contributes to increasing levels of tropospheric ozone. An integrated approach is therefore needed to evaluate the air quality and climate policies that take into account the factors outlined above. Such integrated policies are likely to constitute the best environmental policy strategies in terms of both social and economic costs.

Caption for above figure: An overview of the main categories of air quality and climate change interactions, including a depiction of an example interaction or feedback for each category. Depicted emission sources are examples but do not encompass all emission sources relevant to the depicted interaction. The most relevant components are listed in the brackets following the category. PM (particulate matter) indicates all aerosol sources, including OA (organic aerosol), BC (black carbon), and SO2; O3 (ozone) includes O3 and its precursor compounds, NOx, nonmethane volatile organic compounds (NMVOCs), and CO.

Below, enlarged, is the section from the middle right, above, depicting "plant damage" which = "decreased CO2 uptake by plants" AND "crop losses".  How much you want to bet that nobody pays any attention to the existential threat posed by ozone to all life forms which are dependent upon vegetation - including, of course, us??

Saturday, March 2, 2019

Methane Mania

When it comes to abrupt climate change, the ominous prospect of massive, sudden, catastrophic methane release from melting permafrost and explosive pingos is dramatic and daunting; meanwhile, a more humble but current source of dangerous intensification is flying under the radar even as it constitutes a profoundly existential threat.

On the first of March, the LA Times published a story about the recent accelerating increase of methane in the atmosphere which began to rise, after a lull, in 2007.  Fossil fuel burning and gas leakage results in "heavy" methane, and the research sought to but could not determine whether the rising percentage of "light methane" is accounted for by agricultural practices or natural processes. The scientists were also unable to conclude whether it could be attributed to a loss of atmospheric reactions that break down methane, although they do not believe it is from permafrost melt.
“It’s just such a confusing picture,” Rigby said. “Everyone’s puzzled. We’re just puzzled.”

This flurry of concern is due to the alarming fact that if this rise in methane is not properly identified so that it can be halted and reversed, there is no way to stay within even the dubious safe limits for temperature increase outlined in the Paris accords - no matter what is achieved by way of CO2 reductions - due to the much intensified impact methane provides as a greenhouse gas.

This research hardly began with that study in Global Biogeochemical Cycles; Fred Pearce summarized several similar avenues of pursuit in a 2016 e360Yale article which likewise conclude that the increase is due to microbial emissions as opposed to fossil fuel, biomass burning, or (so far) permafrost release.

Since I have been concerned for over ten years that trees of all species are dying prematurely, everywhere around the earth, from absorbing pollution - a global trend that is utterly ignored by climate scientists, foresters, and atmospheric physicists alike - it occurred to me that there might be a connection between the inability of scientists to account for increased methane and their universal ignorance of widespread forest decline due to ozone.

I remembered a 2012 study in the Yale Forest that found "outwardly" healthy but diseased trees were emitting methane in "flammable concentrations" - which they refused to acknowledge meant something was terribly awry even though this is a quote from the Yale newsletter article :

Diseased trees in forests may be a significant source of methane that causes climate change, according to a study by researchers at the Yale School of Forestry & Environmental Studies (F&ES) published in Geophysical Research Letters.

“If we extrapolate these findings to forests globally, the methane produced in trees represents 10 percent of global emissions,” said Xuhui Lee, a co-author of the study and the Sara Shallenberger Brown Professor of Meteorology at Yale. “We didn’t know this pathway existed.”

The trees producing methane are older — between 80 and 100 years old — and diseased. Although outwardly healthy, they are being hollowed out by a common fungal infection that slowly eats through the trunk, creating conditions favorable to methane-producing microorganisms called methanogens.

...and so I decided to see if anyone else had found similar results.

Google is such a good friend because it turns out that yes, yes indeed, other researchers have detected methane being emitted by trees, but their results are generally shrouded in obscurity.  This is what happens to ecological studies, in contrast to climate change research, due to deep-seated biases and consequent lack of funding.

A March 2017 article in Science Daily describes research of a plot in Maryland and proclaims:

A new study from the University of Delaware is one of the first in the world to show that tree trunks in upland forests actually emit methane rather than store it, representing a new, previously unaccounted source of this powerful greenhouse gas.

The other mechanism that could be causing methane fluxes from trunks is internal rotting or infection inside the tree, which produces an environment where methanogenic bacteria can survive and then methane diffuses out of the tree.
At this moment, the mechanisms of methane production in upland forests are not clear. Methane can be either transported from the soils upward inside the stem and diffused to the atmosphere or produced inside the stem by fungi or archaea -- single-celled microorganisms...
The research quoted above was published in the journal Ecosystems and has an extensive list of references.  Knowledge of this goes back to at least 1974 when the magazine Science published "Methane Formation in Living Trees: A Microbial Origin" which stated:

Visibly healthy hardwood trees located on poorly drained soils contained high pressures of methane. Heartwood from these trees was water-soaked, neutral to alkaline in pH, fetid in odor, and infested with a diverse population of obligately anaerobic bacteria. the bacterium responsible for methane formation in tree. was isolated and characterized as a member of the genus Methanobacterium.

In January, 2018, an article was published titled "Scientists were long baffled by a methane surplus in our atmosphere.  The culprit?  Trees"  about two studies of wetlands, one in the Brazilian Amazon and one in North Carolina, in which both find trees are significant sources of methane unaccounted for in climate budgets.  That wetlands produce methane is well known due to anaerobic conditions; other forests that are silently but inexorably dying are potentially a much vaster source.

In 2009, in Global Change Biology, the abstract for a study about ozone's impacts on trees said:

The northern hemisphere temperate and boreal forests currently provide an important carbon sink; however, current tropospheric ozone concentrations ([O3]) and [O3] projected for later this century are damaging to trees and have the potential to reduce the carbon sink strength of these forests...This implies that a key carbon sink currently offsetting a significant portion of global fossil fuel CO2 emissions could be diminished or lost in the future.

Between the loss of a critical CO2 sink, and the unmeasured increase of forest methane emissions, the ongoing massacre of trees will ensure the 6th mass extinction proceeds much faster than even the most dire expectations.  Methane-fueled wildfires will rage...and the scientists will continue to be puzzled.

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