A clearer path to clean air in China

October 18, 2018, Harvard John A. Paulson School of Engineering and Applied Sciences
Beijing with haze and without haze. Credit: Jonathan M. Moch/Harvard SEAS

For more than 15 years, the Chinese government has invested billions of dollars to clean up its deadly air pollution, focusing intensely on reducing emissions of sulfur dioxide from coal-burning power plants.

These efforts have succeeded in reducing , but extreme pollution events are still a regular wintertime occurrence and experts estimate that more than 1 million people die per year in China from particulate air pollution.

New research from Harvard may explain why. It shows that a key to reducing extreme wintertime air pollution may be reducing formaldehyde emissions rather than sulfur dioxide.

The research is published in Geophysical Research Letters.

"We show that policies aimed at reducing formaldehyde emissions may be much more effective at reducing extreme wintertime haze than policies aimed at reducing only sulfur dioxide," said Jonathan M. Moch, a graduate student at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and first author of the paper. "Our research points towards ways that can more quickly clean up air pollution. It could help save millions of lives and guide billions of dollars of investment in air pollution reductions."

Moch is also an affiliate of Harvard's Department of Earth and Planetary Sciences.

This research was a collaboration between Harvard University, Tsinghua University, and the Harbin Institute of Technology.

Measurements in Beijing from days with especially high particulate air pollution, known as PM2.5, have shown a large enhancement in sulfur compounds, which have been typically interpreted as sulfate. Based on these measurements, the Chinese government has focused on reducing sulfur dioxide (SO2 ), the source of sulfate, as a means to reduce air pollution. As a result of these efforts, SO2 over eastern China has decreased significantly since 2005. The problem is, particulate air pollution hasn't followed the same path.

Moch collaborated with SEAS graduate student Eleni Dovrou and Frank Keutsch, Stonington Professor of Engineering and Atmospheric Science and Professor of Chemistry and Chemical Biology. They found that the instruments used to analyze haze particles can easily misinterpret sulfur compounds as sulfate when they are, in fact, a molecule called hydroxymethane sulfonate (HMS). HMS is formed by the reaction of SO2 with formaldehyde in clouds or fog droplets.

Using a computer simulation, the researchers demonstrated that HMS molecules may constitute a large portion of the observed in PM2.5 in winter haze, which would help explain the persistence of extreme events despite the reduction of SO2.

"By including this overlooked chemistry in air quality models, we can explain why the number of wintertime extremely polluted days in Beijing did not improve between 2013 and January 2017 despite major success in reducing ," said Moch. "The sulfur-formaldehyde mechanism can also explain why polices seemed to suddenly reduce extreme pollution last winter. During that winter, significant restrictions on SO2 emissions brought concentrations below levels of formaldehyde for the first time, and made SO2 the limiting factor for HMS production."

The primary sources of formaldehyde emissions in eastern China are vehicles and major industrial facilities such as chemical and oil refineries. The researchers recommend that policymakers focus efforts on reducing emissions from these sources to reduce extreme haze in the Beijing area.

Next, the team aims to directly measure and quantify HMS in Beijing haze using modified observation systems. The team will also implement the sulfur-formaldehyde chemistry within an atmospheric chemistry model to quantify the potential importance of the -formaldehyde chemistry that creates HMS across all of China.

"Our work suggests a key role for this overlooked chemical pathway during episodes of extreme pollution in Beijing," said Loretta J. Mickley, Senior Research Fellow in SEAS.

Explore further: Study shows why eastern U.S. air pollution levels are more stagnant in winter

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Eikka
not rated yet Oct 18, 2018
The primary sources of formaldehyde emissions in eastern China are vehicles


Formaldehyde and acetaldehyde are a result of incomplete combustion of methanol and ethanol added to vehicle fuels.

https://www.eia.g...id=30072
China's use of methanol in liquid fuels has grown rapidly since 2000

About two-thirds of China's methanol feedstock is produced from coal and the remainder from coking gas (a by-product of steel production) and natural gas.

Methanol is a clean-burning, high-octane fuel component, as the oxygen present in methanol aids in more complete fuel combustion. Blending methanol with gasoline allows refiners to extend China's gasoline supply
Eikka
not rated yet Oct 18, 2018
The challenge of communism is that the communist leadership is rarely an expert of anything except political sciences and sociology, so they lack the actual means to understand any of the decisions they make, and become highly dependent on experts in the field.

But then they become paranoid about the experts and stop listening to any advice in order to not become politically dependent on their advisors and therefore easy to corrupt, which leads back to point one: the communist/socialist leadership that is supposed to think for everyone's behalf and considers itself the brains of the society, is actually dumb, deaf, and blind.

This is true for all forms of government: the more power you invest in a small group of doers and thinkers, the more responsibility you put on a group that simply does not have access to the distributed knowledge of the society. If this group of people were actually wise, they'd simply lift their hands up and tell everyone to mind their own business.
greenonions1
5 / 5 (1) Oct 19, 2018
If this group of people were actually wise, they'd simply lift their hands up and tell everyone to mind their own business
So are you saying that modern societies should not have any clean air regulations? Acid rain in the U.S. (just for example) - would have been taken care of by the wisdom of the group? Same thing for lead in gasoline?
kcaldwel42
5 / 5 (2) Oct 19, 2018
The challenge of communism is that the communist leadership is rarely an expert of anything except political sciences and sociology, ...


Actually, China's leadership are largely scientists and engineers:

https://gineersno...ngineers

Chinese leadership at least seem to be responding somewhat rationally to the environmental challenges of a rapidly industrializing country, unlike a large country that seems to think it is the world's leading democracy run almost entirely by career politicians and millionaires with no scientific background at all.
Eikka
not rated yet Oct 19, 2018
If this group of people were actually wise, they'd simply lift their hands up and tell everyone to mind their own business
So are you saying that modern societies should not have any clean air regulations? Acid rain in the U.S. (just for example) - would have been taken care of by the wisdom of the group? Same thing for lead in gasoline?


No. Standards can be had. It's just that relying on a small group of politically motivated people who are really experts of nothing to come up with the standards is a losing bet, because they're most likely to get it wrong, or get corrupted by the industry simply dictating them standards that let the industry off the hook in terms of pollution etc.

Chinese leadership at least seem to be responding somewhat rationally


It seems that they're rather putting the industry ahead of the environment, because it earns them more money - exactly what western leftist commentators are blaming the capitalists for.
Eikka
1 / 5 (1) Oct 19, 2018
and millionaires with no scientific background at all.


Millionaires are dependent on their business ventures actually turning up with profit. They can't just build ghost cities in the middle of nowhere to pay their buddies in the construction industry, because they're not at the power to tax the entire US population for the money.

The Chinese "rationality" in government is rather more about reacting to their previous mistakes in management, and trying to make the best of a worse situation. They're forced to make some pretty irrational decisions like turning coal into methanol to supplement gasoline, to keep the prices down, which in turn results in formaldehyde pollution and heavy smog.

greenonions1
5 / 5 (1) Oct 20, 2018
exactly what western leftist commentators are blaming the capitalists for
It is interesting to me that the debate always becomes so binary. Look at your use of the word 'leftist.' It is clearly being used as a smear. Using this kind of smear - is a clear tactic to shut down more complex thinking - and default to childish debate. One must be either 'leftist,' or 'rightist.' I live in the U.S. There are clearly benefits to me to living in a relatively free and open society. I am privileged, and I know it. But the wealth divide here is staggering, and the poor people that I work with - live lives of despair. It is complex. No - centralized government does not provide a solution - and history shows us that authoritarianism is not a good way to go (left or right). That does not negate the problems of unchecked capitalism. Selfishness and greed are not good foundations for a fair society either.
Eikka
not rated yet Oct 27, 2018
It is clearly being used as a smear. Using this kind of smear - is a clear tactic to shut down more complex thinking - and default to childish debate


https://en.wikipe...policing
Tone policing (also tone trolling, tone argument and tone fallacy) is an ad hominem and antidebate appeal based on genetic fallacy. It attempts to detract from the validity of a statement by attacking the tone in which it was presented rather than the message itself.


One must be either 'leftist,' or 'rightist.'


That's your strawman. Interestingly coming from a person who has been trying to paint me "anti-progressive" for years.

Reality is complex, but that doesn't mean there aren't some irritatingly simple people living in it. That's what I'm referring to with "leftist" - the people who unquestioningly support any left wing ideas. I'm sure you can find an analog with "rightists", like Objectivist, but that's just making the same point.
Eikka
not rated yet Oct 27, 2018
That does not negate the problems of unchecked capitalism.


What leftists like to blame on unchecked capitalism is 99% of the time actually the result from the collusion of the state and the capitalists, either through direct corruption, or by neoliberalism - essentially crony capitalism.

The issue isn't that capitalism is left unchecked, but that the governments themselves check selectively to benefit certain companies over others. In part, they can't help it because the state isn't omnipresent, omniscient and omnipotent.

How else? The system eventually runs into these sort of closed loops where equal and opposite forces balance out, for example: redistribution of wealth keeps the government in power, and the government keeps policies which maintain the inequality that demands redistribution of wealth. If you disturb the paradigm by saying the "good guys" are actually causing the bad thing, you get called a capitalist pig.
Eikka
not rated yet Oct 27, 2018
The issue in question is about what the role of the state in society really is: should the state be a rulegiver, a leader, a vanguard of sort (progressivism), or an arbiter, judge, an upholder of the common law (conservatism). Then there's all sorts of Machiavellian compromises in between with varying tendencies to either end.

Leftist, socialist, ideas hinge on progressivism - and there lies their fallacies as well. By appointing the state the role of the thinker and leader, and then appointing a government consisting of a handful of individual people, you get elitism and corruption. In trying to do any real progress, you must first secure your rule, which means you have to create a society that cannot remove you from power, which creates an auto-corrupting system that runs from disaster to disaster, as its main priority is maintaining itself. That's what happened in China.

Eikka
not rated yet Oct 27, 2018
As for the Chinese leaders being scientists and engineers,

Trofim Lysenko was a biologist and an agronomist. He became the director of Genetics for the Academy of Sciences in the Soviet Union. You know the rest of the story, like how Lysenko claimed cuckoos are born by their parent birds feeding them hairy catepillars instead of worms. He was mostly responsible for setting Soviet sciences in biology back 50 years compared to the rest of the world, and partially responsible for the same ideas being applied in Mao's great leap forward which resulted in the deaths of tens of millions of people.

Scientists and engineers can be made politically just as well as academically, and in communist countries the two are usually inseparable as you have to be loyal to the party and repeat their ideas to be allowed to study in the first place.

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