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Harbin is a north-eastern Chinese city famous for its toxic smog. The smog has been caused by a combination of the weather, stubble being burnt in fields, coal being burnt for the municipal heating system, and other sources of smoke. In 2013, the smog forced the closure of schools and airports for several days.

Nor is Harbin unique - similar problems are seen in many cities in China, and around the world.

What is needed to fix this problem sustainably?

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This has become too long for a comment.

One can imagine a similar question like this: "Heffingbourne has a problem with all sorts of rubbish being disposed in lakes, forests and the town centre. How can we solve this problem sustainably?" I think the question has very little to do with sustainability. Answers to this hypothetical question are of course "Make sure all rubbish is disposed of sustainably" and "Make sure that no unsustainable rubbish is produced in the first place".

The solutions for Harbin is similar in nature:

  • Make sure that no field stubble is burnt.
  • Make sure that everything producing smoke (cars, factories, fossil-fuel power stations) has up-to-scratch filters installed.
  • Get rid of as many cars/factories/power stations as possible.
    • Replace cars by an affordable and reliable transport system (safe bicycle paths, bus/train network with special offers for commuters).
    • Make factories produce products that last and don't depend on consuming energy.
    • Replace fossil-fuel power stations by (sustainable) wind/water/biogas/whatever power stations.
  • Plant as much forest as possible (and make sure it isn't cut down) to help filter the air.

All of this can be encouraged/enforced by taxing unsustainable behaviour (providing tax relief for sustainable solutions), marketing campaigns, etc.

Anyone can solve this problem theoretically, but in practice it is much harder to achieve.

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Unfortunately, the real answers are rarely as easy as one might think. Let's discuss a couple of major sources of smog in Harbin in turn and why they are hard to address.

Burnt Field Stubble

Being from a rural area myself, for the most part, I tend to wince when people decide that burnt field stubble is the root of all the problems. This tends to be (usually) at most a seasonable problem and rarely something which is a major, ongoing source of smog.

Now the way this is dealt with in Eastern Washington is to require farmers to coordinate field burns with local authorities. The idea is that burning stubble isn't necessarily bad and it can in fact be important for certain kinds of crops, but that when combined with certain weather patterns it can be a bad thing. Therefore, wait for good weather, let the authorities help coordinate when this can be done (i.e. not during an inversion) and this makes a difference.

Coal in Steel Production

Coal in Harbin is used in two things: electrical production and steel smelting. Now, the former has renewable possibilities, but the latter does not at scale. While one can recycle steel in a relatively lossy way using just electricity, smelting and new steel production requires a carbon-rich reducing agent, which generally leaves you with the choice of coal or charcoal.

Currently 12% of worldwide coal production is used for steel production and there is no real substitute. Now, the obvious answer here would be to move the steel mills so that they are well downwind of the city. That helps solve the city's smog problem, but mostly by just moving the problem somewhere else. Moreover in terms of toxic smog, metal smelting is particularly bad and this does include iron smelting. This is due to the fact that all kinds of other stuff from the ore often ends up in the exhaust as well.

Consequently it is simply not true that burning coal has no real purpose. We don't have a way to supply world demand for metals like copper or steel without burning coal and there's no reason to expect that this will change in the reasonably foreseeable future.

So unfortunately for the worst part, it seems unlikely that there is a simple, sustainable solution here. The best answer here is to move the steel production plants downwind of the city far enough that this issue is resolved locally and shifted to someone else.

Transportation

Transportation is one of the major contributing factors to air pollution in just about every city I have been in, from Jakarta to Seattle. The worst offenders are large, commercial diesel vehicles, which often burn cheap fuel in poorly tuned engines (particularly in developing countries).

The answer here is somewhat complex but you have to pay attention to a couple of factors, including:

  1. Diesel quality

  2. Engine maintenance

  3. Commercial vehicle costs and where these cascade to.

Just improving the diesel quality by itself can significantly reduce tailpipe particulate emissions, at least based on my experience. Also see http://www.ncbi.nlm.nih.gov/pubmed/15180069 for an abstract of a paper discussing the impact of fuel formula on particulate emissions.

I would say that my experience seeing Jakarta's air quality improve significantly in the last decade has been mostly due to improved diesel fuel.

So the answer is

  1. Move the steel plants downwind of town

  2. Look for energy reduction strategies and/or changing the coal-fired plant to something better.

  3. Ensure higher grade diesel fuel is used in and around the city

  4. If possible don't allow field stubble to be burned on days when there is an inversion weather-wise.

Now these don't solve many of the problems globally and often amount to pushing problems around. However, unless we stop using steel in industrial quantities, it seems hard to see how the worst offenders (steel production) are going to be addressed globally.

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the problem

Smog is a combination of smoke and fog. So some might think that a solution might be to address the fog, rather than the smoke. But the fog is just making visible the pollution that's around all the time. There will be many incidents of toxic levels of pollution, even when there's no smog. So addressing the smoke is fundamental.

Smoke comes about from burning complex hydrocarbons. In the case of Harbin, and in many similar cases around the world, that's coming from burning coal, and from burning stubble.


technicals

There are two ways to drastically reduce particulate emissions: stop burning the things that release particulates, or trap the particulates straight after combustion. The latter is more expensive, and only addresses part of the problem: particulates are just one of the pollutants: SOx, NOx, CO and CO2 are associated pollutants also released by combustion that will not be caught by a particulate trap.

Stubble-burning used to be common in lots of the world, but has been stopped in many places because of the pollution impact. Ploughing stubble back in prevents the loss of trace nutrients, and can reduce soil erosion. See this pdf report from the US DoE for more about this.. Changing this behaviour will need education for the farmers - there is a common belief that burning kills all pathogens (it doesn't). The Saskatchewan government proposes several alternatives to burning, including chaff spreading, chaff collection, post-harvesting harrowing, and turning surplus straw into an economically useful commodity, selling it as forage.

Coal-burning is also in decline in most of the world, as a nineteenth-century relic that has long past its useful life. It's a major source of greenhouse gases, as well as of particulate pollution. The good news for Harbin, is that because a lot of its heating is provided through the municipal heating system, it's relatively easy to clean up the heating supply for the city. Much easier than it would be for a city such as London, in Europe, where almost of the heating systems are in the individual buildings of the users of the heat, so cleaning up London's heating would mean gaining access to millions of buildings to replace millions of boilers. There are several options for Harbin, and the right answer will be a combination of these:

  • a very large thermal store (a gigantic hot-water tank)
  • electric ground-source heat-pumps with a large area of exposed ground to collect from: note that this is effectively harvesting solar power stored as ground heat, so the rate of extraction of heat mustn't exceed the average annual rate of insolation onto the ground.
  • electric resistance heating for meeting peak demands, and for helping to provide balancing services to the electricity grid.
  • solar thermal collectors
  • possibly biomass boilers with particulate traps
  • geothermal power may be an option, depending on the local geology.

economics

Coal is a cheap fuel, because the buyer of the coal doesn't have to pay for the pollution caused. Burning stubble is a cheap way to clear fields after harvest. One way to tackle this is to change relative prices, so that a cleaner alternative is cheaper: this has had very mixed results around the world. It can be done through a combination of subsidising cleaner options (less public objections, but then energy-efficiency measures no long look as attractive) and through the polluter-pays principle, whereby a tax is added to the polluting process, to internalise the damage costs.


politics

Prices are not the only way to change behaviour. Regulation is another route: enforced regulations to drastically reduce or prevent the destructive choice. This has historically had much higher success in tackling pollution than price mechanisms, but in cultures where belief in the efficiency of markets dominates, it may be more difficult to establish. A change in relative prices can help establish an environment of support for subsequent regulation.

First, you have to identify who the agents of change are: who is it who can change what's happening now. These will often be people with economic and/or political power. Then you have to work out how to motivate them to bring the change about. What do they want, and can you find a way to link the change you are seeking, with the thing they want. Alternatively, what do they want to avoid, and can you find a way to link the status-quo, with the thing they want to avoid?

Harbin does have advantages, and making the most of those advantages could be crucial to success. The municipal power plant makes technology-switch faster and easier. There is money available, including a 10 billion yuan fund to reward efforts to curb air pollution.

And there are national policy initiatives happening right now to curb particulates emission, as part of the Airborne Pollution Prevention and Control Action Plan.


next steps for Harbin

Engage the people. Engage the Party. Engage Academia: this sort of problem will need the input of engineers and social scientists - just the sort of thing that multi-disciplinary university energy departments do. (disclosure - that's what I do)

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This seems to be a good start: Chinese man becomes first to sue government over smog.

To demonstrate how outside-the-box I am thinking, here are some of the options I come up with:

  1. Overthrow the communist government;
  2. Elect Ban Ki-moon for Chinese president;
  3. Secede Manchuria to South Korea;
  4. Declare independence;
  5. Elect Lien Chan for Chinese president;
  6. Secede Manchuria to Russia; (This step will make things worse, because the Chinese is a blight of the earth and Manchuria contains more than 100 million of us. Seceding Manchuria to Russia would devastate Siberia.)
  7. Divert atmospheric rivers to create precipitation;

I speculate that any retired software engineer would have the brains to solve this problem.

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    How is your "outside-the-box" thinking going to help you fix the smog problem? – Earthliŋ Mar 1 '14 at 12:49

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