Particulate and sulphate pollution. Global 'Dimming'.

[Gray-Wolf]

I seem to recall a NASA press release that stated that we were losing up to 50% of our potential AGW 'warming' due to the impacts of other pollutants released along with CO2?

 

The main culprits for this 'cooling/Dimming' were particulate pollution and sulphates.

 

Recently we have seen China commit to cleaning up the air quality in their major cities as the health impacts from their 'smogs' have become too high to accept.

 

Unlike the west that had to develop technology to 'clean up' their air China has 40 years of tried and tested equipment to just buy and install.

 

Personally I am sure that some of the 'rapid warming', that we saw through the 80's and 90's, was augmented by the West's 'clean air acts' so as sulphates and soot were 'scrubbed' out of emmisions the loss of that 'dimming' allowed temps to increase unhindered?

 

China's surge into Energy production from the late 90's onward seems poorly timed as it coincided with us slipping into a period of negative natural forcings. I often wonder how much of the 'slowdown' in the rate of global warming was due to 'naturals' and how much was due to this 'surge' in pollution from Indo-China?

 

Sadly I think we are on the verge of finding out as both the naturals seem to be flipping into their 'positive' phases and China has rapidly begun to 'clean up' its emissions issues?

 

Did we rely on 'dimmed' period temp increases to set the level of CO2 sensitivity? Are we about to discover that CO2 drives far larger temp increases ( when not being impacted by dimming) and that our future will be far warmer than 'consensus' currently warns us?

[Guest]

GW, you may well be right - the other  thing which is coming to the fore now is carbon deposits on ice which could affect the albedo effect.

[knocker]

This crops up when looking at the history of European glaciers.

 

Since the end of the Little Ice Age in the 1850s mean annual temperatures had increased by about 1C by the 1970s and by a further degree since the mid-1980s.. This is almost twice the global mean value and could partly be explained by the higher continuity of the Alps. There have been some decadal fluctuations of the temperature but there is also a clear long-term (secular) trend. While temperature decline in the 1960s is probably due to increased pollution (global dimming) the sharp rise after 1985 could be due to so-called global brightening.

 

A recent study by Paul et al. (2011) revealed that in 2003 glacier cover in the entire Alps was about 2,100 Km² , which is about 30% less than in the 1970s.

Edited January 25, 2015 by knocker

[Gray-Wolf]

I wonder at the local impacts of the Indo-china 'dimming'? I seem to recall that we ended up with some of the east coast pollution ( and when the wind was easterly the Rhine pollution) so did the N.Pacific show any behaviours, since the late 90's, that highlight 'dimming' impacts? I know there were studies across the Indian ocean looking at the impacts of particulate pollution  there ( showing a reduction in cloud droplet size and so a 'brightening' of the cloud tops) but know of nothing looking 'down wind' of the Chinese mainland?

[Gray-Wolf]

Maybe an unfortunate collaboration could be the swing to PDO positive. Low ice over the Pacific sector leads to the triple R setting up (ridiculously resilient ridge) at the same time rapid reductions in China's emissions (due to clean air initiatives) lessens dimming under the high pressure leading to elevated sst's so PDO swings positive.

[iapennell]

Since the pollution of the atmosphere with sulphates and aerosols through industrial activity has had a cooling effect that negates some of the impact of rising CO2 levels; might it not be a good idea to actually ALLOW industries across the World to pump as much sulphur and aerosols into the atmosphere as possible?  It would delay the arrival of the point of dangerous levels of global warming when mean global temperatures are more than 2C above pre-industrial mean temperatures and (in so doing) it would buy more time- maybe 10 to 15 years- for countries to switch to very low/zero-carbon economies.  People in cities could be issued with pollution masks (and/ or we could invest in huge long pipes that lead up to the stratosphere and held aloft by helium balloons that could suck the aerosol/sulphate pollution into the stratosphere where it has more effect on keeping the Earth cooler).

[Gray-Wolf]

I do not know that such pollutants travel across the equator like CO2 does? Could we not end up with the southern hemisphere suffering a bigger hit from the forcing ? With so much ocean down there we could just end up speeding up warming via ocean transport?

[Gray-Wolf]

http://www.nature.com.sci-hub.io/ngeo/journal/vaop/ncurrent/full/ngeo2673.html

Here's a paper looking st the impacts reducing our ( Europe) dirty emissions have impacted Arctic Amplification. with the first signs of China also racing to 'clean up', and stop the deaths from poor air quality, I have to wonder just how much warming has their near instant brown coal addiction, and its high pollution levels, has  offset of the impacts of their hike in global CO2? I would be looking downwind of China to see if we begin to notice positive temp anoms cropping up over land and Sea surfaces over the coming years? Maybe 'the blob' was our first sight of what a cleaner pacific atmosphere can produce?

[Gray-Wolf]

http://www.csmonitor.com/World/Asia-Pacific/2017/0303/China-s-coal-consumption-drops-again-boosting-its-leadership-on-climate-change

So this will be the third year they claim to have reduced amounts and the cancelling of the 103 coal fired plants is to be applauded! With their needs being purely to bring energy to their people if renewables are proving to be a good option? China is a world leader in solar now to the point that we slap a massive tax on their solar panels. Maybe an out of EU UK could drop that levy and flood our shores with cheap solar?

Talking with one of our posters I discovered the AQI in Beijing the other weekend was low to moderate and not what they have been seeing over recent winters so these measure that China is taking do seem to be having real impacts?

If major cities are seeing impact then surely the regions that were 'dimmed' are also now recovering? 3 years of reductions and 3 really hot years with the PDO and IPO both flipped positive........

[Snowyowl9]

Behemoths Of Emission: How A Container Ship Can Out-Pollute 50 Million Cars.

http://www.enfos.com/blog/2015/06/23/behemoths-of-emission-how-a-container-ship-can-out-pollute-50-million-cars/