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I found this an interesting article this morning. Perhaps something we have all contributed to when sitting around a cosy fire after a good day in the mountains
http://www.bbc.co.uk/news/world-europe-39115829
http://www.bbc.co.uk/news/world-europe-39115829
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In reply to SiWood:
I saw this too, from an acquaintance in Chamonix - he seemed quite annoyed by the article...still trying to find out why.
It does seem to diminish the contribution from vehicles - both HGV traffic going through the tunnel, and locals driving around the valley. The bus service was not particularly useful when we were there and we drove more often than we would have liked. On the way up the valley the engine would maybe just get to about working temp getting to Le Tour, and not at all on the way back down.
I'm sure all the Geneva "ski commuters" don't help either. I think it's too simplistic to point the finger at one source (wood burning) and ignore the rest.
I saw this too, from an acquaintance in Chamonix - he seemed quite annoyed by the article...still trying to find out why.
It does seem to diminish the contribution from vehicles - both HGV traffic going through the tunnel, and locals driving around the valley. The bus service was not particularly useful when we were there and we drove more often than we would have liked. On the way up the valley the engine would maybe just get to about working temp getting to Le Tour, and not at all on the way back down.
I'm sure all the Geneva "ski commuters" don't help either. I think it's too simplistic to point the finger at one source (wood burning) and ignore the rest.
In reply to SiWood:
Nothing to do with the 2000 trucks a day and the industrial plant under the viaduct at le Fayet belching out foul smelling smoke, then? Just the humble wood burner.
Nothing to do with the 2000 trucks a day and the industrial plant under the viaduct at le Fayet belching out foul smelling smoke, then? Just the humble wood burner.
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In reply to jon:
surprised there's no mention of the improvement in air quality during the period that the tunnel was shut a few years back
surprised there's no mention of the improvement in air quality during the period that the tunnel was shut a few years back
2
In reply to jon:
So are you saying that the scientists who have measured the relative output of particles from wood burners and motor vehicles are mistaken?
So are you saying that the scientists who have measured the relative output of particles from wood burners and motor vehicles are mistaken?
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In reply to jon:
That would seem to be the case according to this article:
From http://www.atmos-chem-phys.net/16/13753/2016/
"Based on 14C measurements, we can show that the relative fraction of non-fossil carbon is significantly higher in winter than in summer. In winter, non-fossil carbon represents about 85% of total carbon, while in summer this proportion is still 75% considering all samples. The largest total carbon and levoglucosan concentrations are observed for winter aerosols with values up to 50 and 8µg m-3, respectively. These levels are higher than those observed in many European cities, but are close to those for other polluted Alpine valleys.
The non-fossil carbon concentrations are strongly correlated with the levoglucosan concentrations in winter samples, suggesting that almost all of the non-fossil carbon originates from wood combustion used for heating during winter."
That would seem to be the case according to this article:
From http://www.atmos-chem-phys.net/16/13753/2016/
"Based on 14C measurements, we can show that the relative fraction of non-fossil carbon is significantly higher in winter than in summer. In winter, non-fossil carbon represents about 85% of total carbon, while in summer this proportion is still 75% considering all samples. The largest total carbon and levoglucosan concentrations are observed for winter aerosols with values up to 50 and 8µg m-3, respectively. These levels are higher than those observed in many European cities, but are close to those for other polluted Alpine valleys.
The non-fossil carbon concentrations are strongly correlated with the levoglucosan concentrations in winter samples, suggesting that almost all of the non-fossil carbon originates from wood combustion used for heating during winter."
Post edited at 09:51
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In reply to EwanR: Thanks for the think! I was sceptical about the BBC article as it's only source to back up its claim that wood burners the main source was a quote from basically "some guy living in Chamonix". Had they linked the article you have found, it would have significantly helped the argument!
I had heard (but don't currently have time to find a source to back this up...) that the new Euro 6 HGV regulations (oh, haha, dear brexit...we can now ignore those...) have really helped reduce HGV emissions, so maybe back when the tunnel previously closed, there was an improvement? But now it's more down to the wood burners? Just musing...
I had heard (but don't currently have time to find a source to back this up...) that the new Euro 6 HGV regulations (oh, haha, dear brexit...we can now ignore those...) have really helped reduce HGV emissions, so maybe back when the tunnel previously closed, there was an improvement? But now it's more down to the wood burners? Just musing...
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In reply to Alasdair Fulton:
Well it is pretty important to determine what the real cause(s) is. This can only be done objectively by proper, non-agenda driven research into the various culprits (and nothing could be more loaded and agenda-driven than a spurious and irrelevant reference to Brexit!), but there will be a lot of vested interests in the Arve valley just as there are elsewhere. Wood burning does have a cuddly, friendly image, but much of the reduction of really serious, killing pollution that used to be traditionally associated with cities like London was primarily due to progressive restrictions on the direct use of fossil fuels to heat private homes.
I believe there is a similar problem in the Grenoble valley, due to similar topography - a deep valley more or less walled off by mountains all round, intensively developed on the flat valley floor, which inhibits winds and air exchange. Temperature inversions are also very common in the Grenoble valley as they are in the Arve valley, to the extent that a dense cloud blanket up to 1200 m and dazzling sunny skies above is quite normal in Winter. It is also clear that many North European cities get away with being dirtier than they should be because they are so habitually windy, in the case of UK cities due to being close to the turbulent Atlantic ocean. During the recent Winter when a blocking high prevailed for weeks on end, together with very atypical sustained cold clear weather, the air in London became clearly foul as measured both by instruments and by the senses, you could smell and taste it. Despite the brilliant sunshine and clear skies, it became very unpleasant to go outside toward the end of the period.
> It does seem to diminish the contribution from vehicles - both HGV traffic going through the tunnel, and locals driving around the valley..... I think it's too simplistic to point the finger at one source (wood burning) and ignore the rest.
Well it is pretty important to determine what the real cause(s) is. This can only be done objectively by proper, non-agenda driven research into the various culprits (and nothing could be more loaded and agenda-driven than a spurious and irrelevant reference to Brexit!), but there will be a lot of vested interests in the Arve valley just as there are elsewhere. Wood burning does have a cuddly, friendly image, but much of the reduction of really serious, killing pollution that used to be traditionally associated with cities like London was primarily due to progressive restrictions on the direct use of fossil fuels to heat private homes.
I believe there is a similar problem in the Grenoble valley, due to similar topography - a deep valley more or less walled off by mountains all round, intensively developed on the flat valley floor, which inhibits winds and air exchange. Temperature inversions are also very common in the Grenoble valley as they are in the Arve valley, to the extent that a dense cloud blanket up to 1200 m and dazzling sunny skies above is quite normal in Winter. It is also clear that many North European cities get away with being dirtier than they should be because they are so habitually windy, in the case of UK cities due to being close to the turbulent Atlantic ocean. During the recent Winter when a blocking high prevailed for weeks on end, together with very atypical sustained cold clear weather, the air in London became clearly foul as measured both by instruments and by the senses, you could smell and taste it. Despite the brilliant sunshine and clear skies, it became very unpleasant to go outside toward the end of the period.
Post edited at 10:24
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In reply to EwanR:
If the explanation is correct, it is surprising that the Winter/Summer difference is not greater. There is clearly vastly more wood burning in Winter than Summer, just a 10% variation seems pretty small in that context.
> In winter, non-fossil carbon represents about 85% of total carbon, while in summer this proportion is still 75% considering all samples. ....The non-fossil carbon concentrations are strongly correlated with the levoglucosan concentrations in winter samples, suggesting that almost all of the non-fossil carbon originates from wood combustion used for heating during winter.
If the explanation is correct, it is surprising that the Winter/Summer difference is not greater. There is clearly vastly more wood burning in Winter than Summer, just a 10% variation seems pretty small in that context.
In reply to Simon4:
The summer emissions would appear to be from a different source (stuff living in soil)
"For summer samples, the joint use of 14C and levoglucosan measurements leads to a new model to separately quantify the contributions of biomass burning and biogenic emissions in the non-fossil fraction. The comparison of the biogenic fraction with polyols (a proxy for primary soil biogenic emissions) and with the temperature suggests a major influence of the secondary biogenic aerosols."
See section 3.2.3 for the discussion of this.
The summer emissions would appear to be from a different source (stuff living in soil)
"For summer samples, the joint use of 14C and levoglucosan measurements leads to a new model to separately quantify the contributions of biomass burning and biogenic emissions in the non-fossil fraction. The comparison of the biogenic fraction with polyols (a proxy for primary soil biogenic emissions) and with the temperature suggests a major influence of the secondary biogenic aerosols."
See section 3.2.3 for the discussion of this.
In reply to Simon4:
I'm finding that paper a little difficult to follow, so I may have misinterpreted it, but I think what it's saying is (very simply)
Total carbon particulate emissions are 13 times higher in winter than summer.
So, say summer total emissions are 100 "units"*, 75% of that is non-fossil and they have made the assumption that it is "biogenic" because none of the indicators of biomass burning are there. Therefore Carbon from Biogenic sources = 75 "units" and carbon from biomass = 0 units.
In winter, total carbon is 1300 units (13 times summer), 85% of which is non-fossil. I think they assumed biogenic sources were zero in winter. Therefore the winter non fossil emissions (attributed to wood burning) is 1105 "units".
While the ratio of fossil to non fossil doesn't change much summer to winter, the amount of atmospheric carbon particulates goes from effectively zero in summer to 1105
*setting everything relative to summer in normalised units helps comparison
I don't have any knowledge in the above area, so have no basis to argue with their findings. Assuming nothing fundamental is wrong with the study, it does seem that a large percentage of winter emissions is due to lovely, cosy, expensive log burning fires.
I'm finding that paper a little difficult to follow, so I may have misinterpreted it, but I think what it's saying is (very simply)
Total carbon particulate emissions are 13 times higher in winter than summer.
So, say summer total emissions are 100 "units"*, 75% of that is non-fossil and they have made the assumption that it is "biogenic" because none of the indicators of biomass burning are there. Therefore Carbon from Biogenic sources = 75 "units" and carbon from biomass = 0 units.
In winter, total carbon is 1300 units (13 times summer), 85% of which is non-fossil. I think they assumed biogenic sources were zero in winter. Therefore the winter non fossil emissions (attributed to wood burning) is 1105 "units".
While the ratio of fossil to non fossil doesn't change much summer to winter, the amount of atmospheric carbon particulates goes from effectively zero in summer to 1105
*setting everything relative to summer in normalised units helps comparison
I don't have any knowledge in the above area, so have no basis to argue with their findings. Assuming nothing fundamental is wrong with the study, it does seem that a large percentage of winter emissions is due to lovely, cosy, expensive log burning fires.
In reply to John2:
No I'm not saying that. However, it does seem easier to have a go at individual house owners than hugely powerful transport companies and unions or the big industries of the lower valley. Also, I do find it hard to believe that emissions from trucks can have been reduced so spectacularly in such a short time though especially when these trucks are from just about every country in Europe...
Faux news... from la Maison Blanche, peut être?
> So are you saying that the scientists who have measured the relative output of particles from wood burners and motor vehicles are mistaken?
No I'm not saying that. However, it does seem easier to have a go at individual house owners than hugely powerful transport companies and unions or the big industries of the lower valley. Also, I do find it hard to believe that emissions from trucks can have been reduced so spectacularly in such a short time though especially when these trucks are from just about every country in Europe...
Faux news... from la Maison Blanche, peut être?
Post edited at 17:13
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In reply to Alasdair Fulton:
Well thanks for trying to explain it, even if it does rather leave me at, as the old university lecturers would say, a higher level of confusion!
Given that this problem has certainly been known about for quite a long time (even if this is the first time it has hit the British main stream media), it is surprising that there are not more definitive studies and clearer evidence about what is going on. Certainly I have personally been aware of the issue for a fair while, especially in the context of the Grenoble valley (where it is quite well known and totally predictable, given that Grenoble is a much bigger town than Chamonix and the walling in effect is even more pronounced), but also for the Chamonix valley.
The French are really going to have to take some drastic action about this soon, the nearest comparison is to the series of Clean Air Acts in Britain, which first dramatically reduced and then finally abolished the formerly legendary London smogs (and for other cities as well). It can be done and when the situation gets bad enough that most of the public can't help but notice it, a sufficient head of steam gets up that something effective has to be done.
Well thanks for trying to explain it, even if it does rather leave me at, as the old university lecturers would say, a higher level of confusion!
Given that this problem has certainly been known about for quite a long time (even if this is the first time it has hit the British main stream media), it is surprising that there are not more definitive studies and clearer evidence about what is going on. Certainly I have personally been aware of the issue for a fair while, especially in the context of the Grenoble valley (where it is quite well known and totally predictable, given that Grenoble is a much bigger town than Chamonix and the walling in effect is even more pronounced), but also for the Chamonix valley.
The French are really going to have to take some drastic action about this soon, the nearest comparison is to the series of Clean Air Acts in Britain, which first dramatically reduced and then finally abolished the formerly legendary London smogs (and for other cities as well). It can be done and when the situation gets bad enough that most of the public can't help but notice it, a sufficient head of steam gets up that something effective has to be done.
Post edited at 00:02
In reply to Alasdair Fulton:
So the implication is that the 10% difference is 10% of 2 very different absolute quantities, yes?
i.e. an example of percentages concealing much more than they reveal, as they are %s of different amounts.
So the implication is that the 10% difference is 10% of 2 very different absolute quantities, yes?
i.e. an example of percentages concealing much more than they reveal, as they are %s of different amounts.
Post edited at 00:07
In reply to Simon4:
Yep, exactly.
What's still not clear (as neither the paper, nor the article addressed it) is how much of the "health worries" can be attributed to PM 2.5 and PM 10 particulates and how much might be due to NOx or other emissions. More research required!
Yep, exactly.
What's still not clear (as neither the paper, nor the article addressed it) is how much of the "health worries" can be attributed to PM 2.5 and PM 10 particulates and how much might be due to NOx or other emissions. More research required!
In reply to Simon4:
The Crit'air scheme applies to Grenoble, maybe it won't make much difference but at least its a move in the right direction
https://www.certificat-air.gouv.fr/
The Crit'air scheme applies to Grenoble, maybe it won't make much difference but at least its a move in the right direction
https://www.certificat-air.gouv.fr/
In reply to Doug:
Yes, I heard about that, a little anyway.
As you say, the proof of the pudding will be in the eating.
One big problem in Grenoble city is that they have altered the traffic light patterns to guarantee complete snarl-up, with endless traffic jams throughout the day. This is certainly making things much worse from an air-quality point of view, despite what the intention may have been. Probably the intention was in any case largely punitive rather than thought out to address the problem.
Yes, I heard about that, a little anyway.
As you say, the proof of the pudding will be in the eating.
One big problem in Grenoble city is that they have altered the traffic light patterns to guarantee complete snarl-up, with endless traffic jams throughout the day. This is certainly making things much worse from an air-quality point of view, despite what the intention may have been. Probably the intention was in any case largely punitive rather than thought out to address the problem.
Post edited at 09:37
In reply to SiWood:
This isn't very surprising (I was thinking this few years ago when my parents installed woodburners) - its bound to cause a decline in air quality when the popularity increases. Particulates are a particular problem for the inefficient combustion of stoves. There is evidence that similar effects in the UK too. However its not the only source and the traffic on the road up to the tunnel is also a major contributor.
Regardless of source; of more interest to me is the effect of all this particulate matter on the snowpack - if I ran a ski resort I would want to take measures to reduce the amount of particulate landing on the slopes since it absorbs the heat from the sun at orders of magnitude higher than the snowpack itself. In essence you will have a virtually invisible agent in the snow accelerating its melt. Every melting day increases the concentration. If you look at the snow around the entrances to the MB tunnel, its brown!
If you add season after season of deposits on dry glaciers then it must be making a considerable impact.
The Swiss (being the Swiss) decided that they had had enough of the trucks transiting the alps coming through Switzerland and built the base-tunnels to combat exactly this. problem...
> I found this an interesting article this morning. Perhaps something we have all contributed to when sitting around a cosy fire after a good day in the
This isn't very surprising (I was thinking this few years ago when my parents installed woodburners) - its bound to cause a decline in air quality when the popularity increases. Particulates are a particular problem for the inefficient combustion of stoves. There is evidence that similar effects in the UK too. However its not the only source and the traffic on the road up to the tunnel is also a major contributor.
Regardless of source; of more interest to me is the effect of all this particulate matter on the snowpack - if I ran a ski resort I would want to take measures to reduce the amount of particulate landing on the slopes since it absorbs the heat from the sun at orders of magnitude higher than the snowpack itself. In essence you will have a virtually invisible agent in the snow accelerating its melt. Every melting day increases the concentration. If you look at the snow around the entrances to the MB tunnel, its brown!
If you add season after season of deposits on dry glaciers then it must be making a considerable impact.
The Swiss (being the Swiss) decided that they had had enough of the trucks transiting the alps coming through Switzerland and built the base-tunnels to combat exactly this. problem...
Post edited at 12:41
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In reply to petellis:
What are "base-tunnels"?
> The Swiss (being the Swiss) decided that they had had enough of the trucks transiting the alps coming through Switzerland and built the base-tunnels to combat exactly this. problem...
What are "base-tunnels"?
In reply to Simon4:
To my understanding these are long tunnels starting well back from the mountains and at valley level (eg new Gotthard tunnel). They allow trucks to be put onto trains to transit the alps. This avoids trucks accessing higher up in the mountain valleys like with the mt blanc tunnel.
To my understanding these are long tunnels starting well back from the mountains and at valley level (eg new Gotthard tunnel). They allow trucks to be put onto trains to transit the alps. This avoids trucks accessing higher up in the mountain valleys like with the mt blanc tunnel.
In reply to Simon4:
The Swiss didn't like the trucks crossing the alps via Switzerland (I think they used the Simplon pass and another), being valley people the they could see the effects of the pollution from the trucks first-hand. Being landlocked by the EU they were not permitted to simply ban the transit of the trucks so the Swiss Government negotiated the provision of an alternative in the form of two incredibly expensive rail tunnels (deeper and longer than anything that had gone before) on which they would put the trucks to get them across the alps. They held a referendum on the proposals and the Swiss voted to go ahead. They call these new tunnels "base tunnels".
As I understand it all the trucks now drive around Switzerland to avoid paying the train fare... Thus making it a very very expensive political solution! I have not seen figures but maybe traffic in the MB tunnel has increased, which might have some connection to the deterioration of air quality mentioned in the OP.
I look forward to the UK having to jump through similar expensive hoops in the future...
The Swiss didn't like the trucks crossing the alps via Switzerland (I think they used the Simplon pass and another), being valley people the they could see the effects of the pollution from the trucks first-hand. Being landlocked by the EU they were not permitted to simply ban the transit of the trucks so the Swiss Government negotiated the provision of an alternative in the form of two incredibly expensive rail tunnels (deeper and longer than anything that had gone before) on which they would put the trucks to get them across the alps. They held a referendum on the proposals and the Swiss voted to go ahead. They call these new tunnels "base tunnels".
As I understand it all the trucks now drive around Switzerland to avoid paying the train fare... Thus making it a very very expensive political solution! I have not seen figures but maybe traffic in the MB tunnel has increased, which might have some connection to the deterioration of air quality mentioned in the OP.
I look forward to the UK having to jump through similar expensive hoops in the future...
1
In reply to SiWood:
Ah.
The tunnel up from near Sion in the upper Rhone valley is similar I believe.
Incidentally, does anyone know if the Rhone valley, i.e. the Valais canton has the same problem? It is certainly a long valley enclosed (but not fully), by steep mountain walls, though it seems to have a pretty strong katabatic wind blowing along it most of the time, which may make a considerable difference.
Ah.
The tunnel up from near Sion in the upper Rhone valley is similar I believe.
Incidentally, does anyone know if the Rhone valley, i.e. the Valais canton has the same problem? It is certainly a long valley enclosed (but not fully), by steep mountain walls, though it seems to have a pretty strong katabatic wind blowing along it most of the time, which may make a considerable difference.
In reply to petellis:
That invariant law of physics, the law of unintended consequences, strikes again!
Rather similar to the situation in Grenoble when they deliberately snarled up their roads to inhibit traffic, with the result being not that people stopped driving through the city (mostly they had no choice), but traffic ground to a halt endlessly, with stop start driving churning out masses of pollution.
> As I understand it all the trucks now drive around Switzerland to avoid paying the train fare... Thus making it a very very expensive political solution!
That invariant law of physics, the law of unintended consequences, strikes again!
Rather similar to the situation in Grenoble when they deliberately snarled up their roads to inhibit traffic, with the result being not that people stopped driving through the city (mostly they had no choice), but traffic ground to a halt endlessly, with stop start driving churning out masses of pollution.
In reply to jon:
I´ d have put that differently!
It´ s about time private householders faced up to their responsibilities, transport and industry have invested huge sums of money to conform to ever more stringent EU regulations on particulates whereas private householders have been free to f#ck up their neighbours air however they like.
In happy Germany where there are considerable restrictions on wood fired heating it still produces more particulates than the entire transport sector and as the cure is neither particularly expensive or difficult doing nothing is just burying ones head in the sand.
> No I'm not saying that. However, it does seem easier to have a go at individual house owners than hugely powerful transport companies and unions or the big industries of the lower valley. Also, I do find it hard to believe that emissions from trucks can have been reduced so spectacularly in such a short time though especially when these trucks are from just about every country in Europe...Faux news... from la Maison Blanche, peut être?
I´ d have put that differently!
It´ s about time private householders faced up to their responsibilities, transport and industry have invested huge sums of money to conform to ever more stringent EU regulations on particulates whereas private householders have been free to f#ck up their neighbours air however they like.
In happy Germany where there are considerable restrictions on wood fired heating it still produces more particulates than the entire transport sector and as the cure is neither particularly expensive or difficult doing nothing is just burying ones head in the sand.
3
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