Thursday, October 10, 2013

What are the effects of aviation on the water cycle?

After reading his article[1] in Scientific American magazine in which he talks about persistent contrails, cirrus clouds and aviation emissions in general , I wanted to ask David Biello, journalist editor of the magazine, if the effects on the hydrological cycle of these aviation emissions are similar to those of geoengineering .

I think that due to the limit of 140 characters I could not articulate my question clearly, but still  Mr. Biello’s kind reply and the short conversation  that followed were interesting to me and gave me much to think about.

In the first tweet was the title of the article, the link and my original question:

(OE) Airplane #Pollution Needs to Descend
@dbiello hydrological cycle effects of #aviation #emissions = #Geoengineering?

Leaving aside the issues of the hydrological cycle and the concept of intentionality, his reply:

(DB) "that's a very good question. i'd say yes as "soft" geoengineering but no formally since unintentional (at this point)”

Indicates to me that in fact he believes, aviation emissions are a form of ‘soft’ geoengineering

Blogger John Kennard pointed out that:

(JK) "In the week-long aviation shutdown after 9/11 in the US the country noticeably cooled. #greenhouse #AGW"

Regarding the flights stoppage after 9/11 it was noted that daytime temperatures rose and nighttime temperatures fell.[2]  But in general persistent contrails and cirrus clouds from aviation contribute to global warming.

The Working Group I of the IPCC 's latest report, the AR5, specifically confirms the greenhouse effect (positive forcing) by the artificial cloudiness produced by aviation,[3] but does not quantify or even explore its effects on the hydrological cycle. The report recognizes that there is a relationship between aerosols in general and changes in precipitation but admits that the magnitude of these changes are still un-clear.[4]

The report adds this about the RF “This forcing can be much larger regionally but there is now medium confidence that it does not produce observable regional effects on either the mean or diurnal range of surface temperature."

Well, the short conversation continued, but concentrated on the theme of 'intentionality' which is an integral part to the definition of geoengineering as noted by both David Biello and Dr. Victor Galaz, Associate Professor at The Stockholm Resilience Centre and co -author of the CBD’s paper: IMPACTS OF CLIMATE-RELATED GEOENGINEERING ON BIOLOGICAL DIVERSITY.[5]

There are various definitions of geoengineering, definitions that could still change, but they always include the concept of intentionality.  In Wikipedia (en español) I wrote:

(translated) The Royal Society defines geoengineering as “the deliberate large-scale manipulation of the planetary environment to counteract anthropogenic climate change" [6] [7]

In this definition the concept of ' intentionality' seems to be very concise and easy to understand.

But when you want to talk about the known effects of commercial aviation and marine traffic of cargo ships, which can be very similar to those of a geoengineering program, the concept of 'intentionality 'becomes very complex.[8]  To me it seems like very 'meta ' because it attempts to describe an actual, visible and ongoing reality as… beyond reality; as if it was not happening, or was only hypothetical. In the end it becomes something like…

In a very brief way and specific to aviation, some philosophical concepts might say that:

Although it is known that certain actions when traveling by plane or that the mere act of traveling by plane produces an effect comparable to geoengineering, if the main (perceived)  intention is transportation or any other purpose that is not specifically declared to be for changing the climate, then performing these actions and indeed change the climate is not geoengineering.  It is to say that (all) side effects are 'unintended'. Similarly if it is known that taking certain actions would prevent climate change, but they are not taken, or even preventing them and therefore produce climate change, this still is not geoengineering. And what's more, purposely using fuels or additives known to ultimately exacerbate climate change, e.g. through cloudiness, or increased aerosol generation would not constitute geoengineering if it is perceived as being done with intentions other than geoengineering.
I disagree with this concept of intentionality, but I will not write about it today.

My intention as I said earlier, was to ask about the effects of aviation on the hydrological cycle, so I asked again in a different way.

(OE) I'd like to ask: do #aviation #emissions affect the #hydrological cycle in a way similar to what a SRM #geoengineering prog. would?

(DB) i think it depends on the scale of a SRM geoengineering prog. so, for example, a global sulfate distribution would be bigger...

Noting that the aviation’s sulfate distribution is global, my reply included a link to a study: [9]

(OE) But #aviation's sulfate dist. is global.

In his last reply David Biello emphasizes:

( DB ) like i said, depends on scale of the geoengineering effort then, doesn't it

I agreed, it is relative. I wanted to ask if there was an up to date quantification of the effects of aviation on the hydrological cycle both globally and regionally. In other words: are there measurements of the effects of aviation on rain, drought, etc.; at global and regional level ? Who has done it? I asked the question this way:

(OE) yes! But as of now does anyone know, or is there quantification of actual present #aviation effects on global and regional hydro?

That was it. There was no reply.

Anyway I am thankful for the twitter chat. It was more than I expected.

For me it is clear that there is a relationship between aviation and the hydrological cycle, and the fact that there is not much information, or that is not easy to find it; is very disturbing, especially in light of the recent years of drought and floods that have been suffered globally. How much of it can be attributed to aviation? Disturbing, but there may be hope of reducing those effects if measures (but not more geoengineering!) are taken to reduce the impacts of aviation.

I’ll keep looking for studies, or wait to see if the, still to come, IPCC reports address the issue specifically and in depth.


November 16, 2013

“But I didn’t mean it!” Why it’s so hard to prioritize impacts over intents.
By Melanie Tannenbaum | October 14, 2013

“It’s not about intent. It’s about impact.”

“The overall message in all of these conversations is that when someone does something hurtful or offensive to another person, the perpetrator’s intent is not what’s most important when gauging the appropriateness of an action — in fact, many would say that it is inherently privileged to redirect the focus of a conversation to the perpetrator’s (presumably harmless) intentions, rather than focusing on the feelings and experiences of the person who has been harmed. So, the point is that we really need to focus on impact, not intent. Was someone hurt by something? Was there a negative outcome? Did someone suffer? If so, that is what’s important. Whether or not the perpetrator meant to cause harm is not.”

“As long as we continue to engage with societal issues in which there is an agent with intentions and a patient receiving the consequences of those actions, we must all struggle to tease apart these issues of intent and impact. We must all focus on how actions that harm others — regardless of intent — need to be addressed, not pushed under the rug because the agent “didn’t mean” to do anything wrong. Yet at the same time, we must learn to understand our own cognitive biases, and how we can’t continue to treat intent and impact as if they are cognitively separate, orthogonal factors.”

Geoengineering: Goldilocks effect to cloud seeding

Get this climate techno-fix right, and the effect is dramatic, Get it wrong, though, and you make the problem worse. So how do you get this to work as planned?
By Philip Ball - BBC

November 10, 2013

Who bears the cost of airline emissions?

"Aviation is today responsible for some 2% of the planet’s man-made CO2 emissions. But when the effects of nitrogen oxide emissions, water vapour, soot and sulphates, contrails and enhanced cirrus cloud formations are also factored in, the best scientific estimates put aviation’s overall contribution to global warming at 4.9%.

The International Civil Aviation Organisation (ICAO) has forecast that CO2 emissions from international aviation (about 60% of total aviation emissions) will grow from approximately 400 million tonnes in 2010 to 650 million tonnes by 2020. Unchecked, there may be a 274% increase in the fuel used by airlines by 2050, measured against 2006 levels.

Put plainly, the aviation industry bears a share of responsibility for the accelerated drought-flood cycle that climate change will bring to countries such as India." (emphasis mine)

October 24, 2013

Volcanic-ash sensor to take flight 
Researchers will fly jet towards giant artificial particle cloud to test safety device.

October 23, 2012:

The conversation here:

Added paragraph:

And what's more, purposely using fuels or additives known to ultimately exacerbate climate change e.g. through cloudiness, or increased aerosol generation, would not constitute geoengineering if it is perceived as being done with intentions other than geoengineering.



[1] Airplane Pollution Needs to Descend
Airplanes may only contribute roughly 2 percent of the greenhouse gases warming the atmosphere. But they are one of the fastest growing sources. David Biello reports

[2] Jet Contrails Alter Average Daily Temperature Range

Chapter 7: Clouds and Aerosols - Final Draft Underlying Scientific-Technical Assessment  (pg. 7-5]

Chapter 7: Clouds and Aerosols - Final Draft Underlying Scientific-Technical Assessment (pgs. 7-55-58)


[6] Geoingeniería

[7] Geoengineering the climate: science, governance and uncertainty

[8] Starting a flood to stop a fire? Some moral constraints on solar radiation management
by David Morrow

[9] Effects of aircraft on aerosol abundance in the upper troposphere
G. V. Ferry
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A #Geoengineering #Climate Issues blog - Geoingeniería by Oscar and Jocelyn Escobar is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.Licencia Creative Commons
A #Geoengineering #Climate Issues blog por Oscar y Jocelyn Escobar se distribuye bajo una Licencia Creative Commons Atribución-NoComercial 4.0 Internacional.