Archive for 2018

A hitchhikers guide through the Berlin traffic galaxy

Monday, December 10th, 2018

For those who are interested in what keeps us busy – here is one thing: Local politics and in particular Berlin traffic planning.
If you are able to endure german subscripts you might watch our attempt to convince people that their ideas of traffic load removal may have the opposite effect of what they think.
If not -Tim had only very few hours to work on the music but you might just enjoy his lofty kind of ambient electronica.

november note

Friday, November 30th, 2018

This month no randform post.

ShutterSploshShredderPlots

Sunday, October 7th, 2018

Remark: The code as posted at the randform post ShutterSploshScatterPlots needs to include the new Content Security Policy.
That is you have to embed the following lines (at least thats how it worked here for the moment) into your html head:

<meta http-equiv="Content-Security-Policy" content="default-src 'self'; script-src 'self'">
<meta http-equiv="X-Content-Security-Policy" content="default-src 'self'; script-src 'self'">
<meta http-equiv="X-WebKit-CSP" content="default-src 'self'; script-src 'self'">

Moreover the javascript has to be pasted into a separate file and referenced accordingly within your html body, like for example as:

 <script src="shutter.js" type="text/javascript"></script>

In case you feel a bit overcharged by all that – as a courtesy for you I quickly filmed the program output with my mobile and turned it into a gifanimation, which you can watch after the ” Read the rest of this entry”.

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september note

Sunday, September 30th, 2018

This month no randform post.

august note

Friday, August 31st, 2018

This month no new randform post.
The previous post is hard enough to digest.

On a personal note:
The previous post is actually a main result of a phase between mid/end 2012 – spring 2015. In this phase I was investigating in which way I could apply my math/physics and visualization skills to climate science. In 2015 I more or less ended the investigation, since I found that -amongst others- my programming skills were not good enough for a continuation on a more professional level and started to work in a company in which I have been working since then.

simple greenhouse gas models

Sunday, July 29th, 2018

Rotatable with your mouse after you click on “Read the rest of this entry“.

Most of randform readers might have heard that the socalled greenhouse effect is one of the main causes of global warming.

The effect is not easy to understand. There are two posts which give a nice intro to the greenhouse effect on Azimuth. One is by Tim van Beek and one is by John Baez.
The greenhouse effect can also be understood in a slightly more quantitative way by looking at an idealized greenhouse model.

In the above diagram I now enhanced this idealized greenhouse model (as of Jan 2017) in order to get an idea about the hypothetical size of the effect of an absorption of non-infrared sunlight and it’s reradiation as infrared light, i.e. the possibly effect size of a certain type of fluorescence.

I sort of felt forced to do this, because at the time of writing (February 2017) the current climate models did not take the absorption of UV and near infrared light in methane (here a possible candidate for that above mentioned hypothetical greenhouse gas) into account and I wanted to get an insight into how important such an omission might be. The simple model here is far from any realistic scenario – in particular no specific absorption lines but just the feature of absorption and reradiation is looked at.
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insert April 24, 2023
My first email asking about the inclusion of shortwave (UV and near infrared) radiation into the radiative forcing of methane to Gunnar Myrhe was on Sept. 10, 2015. The last answer I got was in January 2017, when I pointed out in a new email that there are problems with the evaluation of solar radiation, as explained in the randform post Information about solar irradiance measurements sought (see also What is going on at the Sun?). The answer was basically that he is busy with meetings etc.

Meanwhile I had found out, by searching the internet, that the problems had been somewhat adressed.

That is in: Radiative forcing of carbon dioxide, methane, and nitrous oxide: A significant revision of the methane radiative forcing by M. Etminan1 , G. Myhre2 , E. J. Highwood 1 , and K. P. Shine it was found that

Methane’s RF is particularly impacted because of the inclusion of the shortwave forcing; the 1750–2011 RF is about 25% higher (increasing from
0.48Wm−2 to 0.61Wm−2) compared to the value in the Intergovernmental Panel on Climate Change (IPCC) 2013 assessment; the 100year global warming potential is 14% higher than the IPCC value.

The new value came from the inclusion of absorption spectra with shorter wavelengths.

The new value was inserted into climate simulations in:
Understanding Rapid Adjustments to Diverse Forcing Agents
Accordingly the new IPCC report writes in chapter 7: 7.3.2.2 Methane:

The SARF for methane (CH4) has been substantially increased due to updates to spectroscopic data and inclusion of shortwave absorption (Etminan et al., 2016). Adjustments have been calculated in nine climate models by Smith et al. (2018b). Since CH4 is found to absorb in the shortwave near infrared, only adjustments from those models including this absorption are taken into account. For these models the adjustments act to reduce the ERF because the shortwave absorption leads to tropospheric heating and reductions in upper tropospheric cloud amounts. The adjustment is –14% ± 15%, which counteracts much of the increase in SARF identified by Etminan et al. (2016). Modak et al. (2018) also found negative forcing adjustments from a methane perturbation including shortwave absorption in the NCAR CAM5 model, in agreement with the above assessment. The uncertainty in the shortwave component leads to a higher radiative modelling uncertainty (14%) than for CO2 (Etminan et al., 2016). When combined with the uncertainty in the adjustment, this gives an overall uncertainty of ±20%. There is high confidence in the spectroscopic revision but only medium confidence in the adjustment modification.

A very new evaluation in Methane’s Solar Radiative Forcing finds:

Including the impact of SW absorption on stratospheric temperature increases tropopause SARF by 0.039 W m−2 (or 7%) compared to the LW-only SARF.

The article Understanding Rapid Adjustments to Diverse Forcing Agents however also evaluated what a 2% increase of the solar constant parameter shows in the climate models and found (see Fig. 1) that the radiative forcing increases as if one would double the CO2 parameter or triple the CH4 parameter.

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The above diagramm shows the earth temperature in Kelvin as a function of two parameters, as given by this enhanced model. The two parameters can be seen as being (somewhat) proportional to densities of a hypothetical greenhouse gas, which would display this type of fluorescence. That is the parameter x is seen as (somewhat) proportional to the density of that hypothetical greenhouse gas within the atmossphere, while y is (somewhat) proportional to the density near the surface of the earth. Why I wrote “somewhat” in brackets is explained below.

The middle of the “plate” is at x=0, y=0 (please hover over the diagram) which is the “realistic” case of the idealized greenhouse model, i.e. the case where infrared absoptivity is 0.78 and the reflectivity of the earth is 0.3. The main point of this visualization is that linearily increasing x and y in the same way leads to an increase of the temperature. Or in other words, although raising x by a certain amount leads to cooling this effect is easily trumped by raising y by the same amount.

As far as I learned from discussions with climate scientists the omission of non-infrared radiation in the climate models was mostly motivated by the fact that an abpsorption of non-infrared is mostly happening in the upper atmossphere (because methane is quickly rising (but there are also circulations)) and thus leading rather to a global cooling effect than a global warming effect and so it in particular doesn’t contribute to global warming. The enhanced simple model here thus confirms that if absorption is taking place in the upper athmossphere then this leads to cooling. The enhanced model however also displays that the contribution of methane that has not risen, i.e. methane that is close to the earth surface, is to warm upon absorption of non-infrared light and that the effect of warming is much stronger than the cooling effect in the upper athmosphere. Unfortunately I can’t say how much stronger for a given amount of methane, since for assessing this one would need to know more about the actual densities (see also discussion below and the comment about circulations). Nonetheless this is a quite disquieting observation.

I had actually exchanged a couple of emails with Gunnar Myrhe, the lead author of this corresponding chapter in the IPCC report, who confirmed that non-infrared light absorption in methane hasn’t sofar been taken into account, but that some people intended to work on the near-infrared absorption. He didn’t know about the UV absorption that I had found e.g. here (unfortunately my email to Keller-Rudek and Moortgat from 2015 whether there is more data for methane especially in the range 170nm-750nm stayed unanswered) and thanked for pointing it out to him. He appeared to be very busy and as drowning in (a lot of administrative) work, so that I fear that those absorption lines still might not have been looked at. That is also why I decided to publish this now. I sent a copy of this post to Gunnar Myrhe, Zong-Liang Yang and John Baez in June 2017, where I pointed out that:

I have strong concerns that the estimations of the global warming potential of methane need to be better assessed and that the new value might eventually be very different then the current one.

– but I got no answer.

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Work-to-rule?

Saturday, June 30th, 2018

Last year (Jan 2017) there was a long essay in the german newspaper “Die Zeit” (“The time”) about how important a natural scientific evaluation could be for historical research. The essay: “Darum hatte Hitler keine Atombombe” (“That’s why Hitler had no nuclear bomb”) was written by physicist Manfred Popp. A very brief summary of his argumentation is that a lot of historical research about german nuclear research during Nazi times was more or less flawed due to missing knowledge or misinterpretations of physical facts.

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spinach

Tuesday, May 29th, 2018

The frequent randform reader knows that a lot of randform posts are concerned with questions about how to keep earth as a habitat for humans. One of the biggest problems seems to be: population growth. That is humans are the root cause of “pollution”, they are to a great extend causing climate change, they massively reduced the habitat for other beings including those in their own food chain and if their own strive for efficiency keeps on like that, then they (partially?) need to abolish themselves and eventually (?) start the AI machine population explosion-if they haven’t wiped themselves out beforehand in their wars for ressources.

But what really are the reasons for this human population growth?

This seems to be a very deep systemic question, but for me it is rather suggestive that this strive or “competition for efficiency” is playing a major role here. So today I would like to discuss this quest for efficiency again a bit at the example of agriculture.

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Limits to Growth

Tuesday, April 24th, 2018


People in front of a butcher shop

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march 2018 omittance

Saturday, March 31st, 2018

No post in march 2018. Mostly due to medical incidents.