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Trends in Atmospheric SF6

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NOAA has created a new site "Trends in Atmospheric SF6" on its website.
It reports monthly about the actual SF6 concentrations at sea level. SF6 is a very powerful GHG and per kg 26,087-fold more intense than CO2; converted into molar activity the factor is 86,678. I translated the CO2 equivalent into the concentration graph. It is not much (we talk about ppt concentrations), but more than nothing, and constantly increasing (higher than linearly = acceleration).

The latest value is for May 2019:
May 2019:     9.90 ppt
May 2018:     9.55 ppt
Last updated: September 18, 2019

The annual increase is 0.35 ppt, above all average annual increase rates (see below)
Annual increase rates (averaged over 5 years):
1998-2003: 0.20 ppt
2003-2008: 0.24 ppt
2008-2013: 0.29 ppt
2013-2018: 0.33 ppt
See attached graphs (concentration and increase rates, expressed as percentage)

Link to the website:


--- Quote ---Sulfur hexafluoride (SF6) is an inorganic, colorless, odorless, non-flammable, non-toxic but extremely potent greenhouse gas, and an excellent electrical insulator. SF 6 has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. It is a hypervalent molecule. Typical for a nonpolar gas, it is poorly soluble in water but quite soluble in nonpolar organic solvents. It is generally transported as a liquefied compressed gas. It has a density of 6.12 g/L at sea level conditions, considerably higher than the density of air (1.225 g/L).
--- End quote ---

Link >>


--- Quote from: kassy on September 15, 2019, 01:27:27 AM ---This is also related to renewable energy:

--- Quote from: AbruptSLR on September 14, 2019, 12:42:11 AM ---Per the linked article, sulfur hexafluoride, is the most powerful GHG known to man, and its emissions have been rising rapidly in recent years:

Title: "Climate change: Electrical industry's 'dirty secret' boosts warming"

Extract: "It's the most powerful greenhouse gas known to humanity, and emissions have risen rapidly in recent years, the BBC has learned.

Sulphur hexafluoride, or SF6, is widely used in the electrical industry to prevent short circuits and accidents.

But leaks of the little-known gas in the UK and the rest of the EU in 2017 were the equivalent of putting an extra 1.3 million cars on the road."

--- End quote ---

See the artice for details but here is a further quote:

--- Quote ---Are there alternatives - and are they very expensive?
The question of alternatives to SF6 has been contentious over recent years.

For high-voltage applications, experts say there are very few solutions that have been rigorously tested.

"There is no real alternative that is proven," said Prof Manu Haddad from the school of engineering at Cardiff University.

"There are some that are being proposed now but to prove their operation over a long period of time is a risk that many companies don't want to take."

However, for medium voltage operations there are several tried-and-tested materials. Some in the industry say that the conservative nature of the electrical industry is the key reason that few want to change to a less harmful alternative.

"I will tell you, everyone in this industry knows you can do this; there is not a technical reason not to do it," said Louis Shaffer from Eaton.

"It's not really economic; it's more a question that change takes effort and if you don't have to, you won't do it."
--- End quote ---

--- End quote ---

The averages for July 2019 have been published:
July 2019:     9.97 ppt
July 2018:     9.61 ppt
Last updated: November 05, 2019
The annual increase of 0.36 ppt is a tiny bit higher than in May.
The relative increase of 3.7% is remarkable. If you put that relation onto CO2 concentrations, the annual increase would be around 15 ppm (calculation based on 410 ppm). But in contrast to CO2 SF6 has no natural sinks.

Finally, SF6 also received an update.

August 2019:     9.98 ppt
August 2018:     9.63 ppt
Last updated: December 05, 2019

The annual increase of 0.35 ppt is comparable to the values we saw the last months.
Interestingly, the relative increase (0.35 ppt = 3,6 %) is much higher than that of the other greenhouse gases. It is probably the lack of natural sinks that causes this effect.


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