September 02, 2023

On Average, Is Western Washington Air Quality Getting Better or Worse?

 Several folks have complained to me about the bouts of wildfire smoke during recent summers.  They note that we have had more smokey summer days during the past five years than previously.

All very true. Summers have brought more wildfire smoke incidents lately (although still far less than 100 years ago)


But now let's ask perhaps a more important question:  for the entire year has the exposure to poor air quality gotten better or worse?

And the answer to this question may surprise:

Overall air quality, averaged over the year, has gotten better.

How can this be?   Because air quality during the winter has substantially improved.

Want to know something even stranger?   Much of that air quality improvement has occurred because we have replaced a renewable heat source (wood) with a fossil fuel (natural gas).

Since I know these results are perhaps controversial to some, let me note that I have confirmed them with a local professor specializing in local air quality and with folks in the Puget Sound Clean Air Agency

Let me begin by showing you a plot of the annual average of PM2.5--small particles smaller than 2.5 microns.  Such small particles can move deep into our lungs.  There was a significant decline in the concentration of such nasty particles between 2000 and 2010 and then they held relatively steady, with some ups and downs.


Black carbon is another nasty airborne substance (see below for some Puget Sound sites).  Substantially down over time.


To get an idea of how things have changed over the past two decades, let me show you two- year plots of PM2.5 at the Seattle Duwamish observing site.  For the last two years, the biggest peaks--which were generally short-lived --were in summer.  Wildfire smoke events.

But in 2000-2002,  there were extensive and persistent periods of degradation during the winter.    It would have been even worse in the 1980s during the winter.
The trend towards more summer smoke has to do with the wildfires, which have become more active for a  number of reasons (discussed in previous blogs at length).

The winter improvement has mainly occurred from a substantial drop in the use of wood stoves.  If you read the Seattle Times during the 80s, you would see whole pages dedicated to advertising wood stoves.   People would proudly store cords of wood near their homes.   Such wood stoves were very inefficient and dirty, putting a pale of smoke over many neighborhoods.   Excellent work by local air quality agencies, such as Puget Sound Clean Air Agency, has also been important, including call burn bans when air quality is worsening.

Wood fireplaces were also popular.   Fortunately, burning wood has declined precipitously, with many switching to natural gas, which burns cleanly and is MUCH less of a hassle (no lugging in wood, no cleaning ashes.)


Another major change was the switch from oil to gas furnaces, with the latter being much cleaner.  Obviously burning wood and oil were mainly wintertime activities, and thus that is when the air quality degraded. 

Bottom Line

Overall, we are breathing better air in western Washington, with cleaner winter air outweighing the increased numbers of wildfire smoke intrusions mainly during late summer.  If our region would take the necessary steps to reduce large wildfires (e.g., thinning forecasts, prescribed burns, de-energizing powerlines during dangerous situations), our air quality could be even better.

21 comments:

  1. Replies
    1. heat pumps are an excellent technology. But they are expensive and some folks like to watch the magic of dancing flames. And then there is the issue of securing enough power for them. As you know, in the middle of winter there is little solar and wind in our region. That is why we need more nuclear power if we are serious about moving away from fossil fuels. And then there is the issue of finding the electricity to charge EV vehicles!

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    2. There has plenty of grid capacity, no need to limit your thinking to small sub sections of the interconnect. We need our narratives to be as broad as the actual grid is. The time to electrify everything is now. Natural gas infrastructure is sticking our heads in the sand.

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    3. Last year over half of the electricity generated in the US came from fossil fuels. Until we fix that there's no point in mass electrification. We're burning fossil fuels to create heat, converting that into kinetic energy, converting that into electricity, transmitting it hundreds of miles, and then converting it BACK into heat (talking about electric heaters and stoves). Every time the energy is converted to a different form there is waste. Much more efficient to just burn the fuel where the heat is needed. Once we can generate more electricity without burning fossil fuels that will be the time to electrify.

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    4. And when the environmentalists rip.out dams, then what? Erik, what's your specific plan besides trolling?

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    5. Sorry kids, we didn't deal with the whole climate change thing because "some folks like to watch the magic of dancing flames"

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    6. Heat pumps = noise pollution. Yes, noise pollution is an important problem.

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    7. Hey Dr. Mass, please comment on the Burning Man Fiasco in a future post. Thank you.

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  2. We just built a new house. No fireplace, but a propane furnace (no natural gas service here). We bought an electric fireplace for those times when we want to sit in front of a "fire." We'll eventually add a propane fire pit instead of a wood fire pit.

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  3. I've had more than one discussion with friends and relatives over wood stoves. They insist that since they are modern stoves built to federal standards they "don't pollute". Of course, their real reason for burning wood for heat is that they don't want to pay for natural gas or electricity. What they don't understand is that wood, by its very nature is dirty fuel and all of the other things in wood besides the hydrocarbons just get atomized and distributed in the atmosphere. Natural gas has much fewer impurities in it and burning it produces a much less potent greenhouse gas than the natural gas itself so it is better to burn natural gas than to let it disperse into the atmosphere.

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    Replies
    1. It's best left in the ground! Nothing natural about it.

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  4. Once again you bring up the question of cognitive dissonance among our so - called "elites." They don't want to cut down more trees (and also use them for fuel) because of AGW, but in the same token think natural gas extraction is somehow even worse. The enviro NGO's used to extol the benefits of natural gas instead of coal and nuclear but here we are, stuck in the middle with them (h/t to Gerry Rafferty). They simply want us all (except them, of course) to go back to living in caves and subsisting on grubs.

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    Replies
    1. Cavemen had heat pumps EVs and iPhones!?

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    2. We'll strike that post as non - responsive...just like your other posts in this thread.

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  5. With the CCA juicing natural gas rates, (despite Bob Ferguson pushing PSE to not itemize the compliance cost on ratepayers' bills) some customers are going to turn down their thermostats in favor of lighting their wood stoves more often.

    Thanks to the ruling political machine for helping us to go backward, trading the best heating fuel ever discovered for an older one that launches carcinogenic particulate matter into the air.

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  6. I have an all-electric house with a heat pump; AC + heating.
    Heat Pumps (HPs) require electricity. In a climate where winter
    temperatures can go to -20°F an emergency source of heat is necessary. (The HP has resistors for heating below the efficient limit of compression.) Piped gas is not an option. A wood stove with a catalytic burner works for emergency or supplemental heat. You can heat water or food (stew), and if desired a battery powered fan can move the heat into other rooms.
    These wood stoves, like Blaze King from Walla Walla (and others), are much better than the old iron-box type. I think ours was called an Earth Stove. WA DOE gave us $$ to turn it in. Those $$ paid the sales tax on the new one.
    The WA DOE program was about 8 years ago. It would be interesting to know how successful that was.
    Some improvement in air quality would occur as the old iron-box stoves were removed from homes. Old ones produced 5x the pollution, deposit more creosote, and use about 1/3rd more wood.
    It is illegal to sell, install or give away a wood heating appliance or factory-built fireplace that is not certified to meet Washington state air emission standards.
    I think I saw where old stoves must be removed before a house can be sold. At the moment, I can't find this rule.

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    Replies
    1. In the milder climate of Western Washington, my Blaze King is sufficient to heat my 1000SF house throughout the winter.

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  7. Prof. Mass, I can't tell you how much I enjoy your ability and of course expertise at using actual and transparent data to reveal truth about climate and meteorology of our region and beyond. You provide facts and evidence to explain and teach what too many in higher education institutions and media, especially Seattle-metro, try to obfuscate and ignore/cancel. Thank you.

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  8. Thanks for addressing OUTSIDE air quality, Cliff. Of course, INDOOR air quality is not in scope of "weather", but it is of equally important; most of us spend much more time indoors than out. Remember the days of rampant cigarette smoke and blue rooms. And airplanes full of cigarette smoke. When the outside air quality gets bad, we are told to stay indoors, but is that really better? The inside air all comes from outside. Hopefully modern HVAC systems filter the air, but that, too, takes energy.

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  10. At both our houses, we have top-of-the-line high-efficiency heat pumps and yet still, we burn cords of wood all winter long, day and night. I will always burn wood as a primary heat source; it is cheap and easily accessible to me, is fun and pleasant, and in my opinion makes the house much more enjoyable. For the cost of our heat pump, I can get nine-hundred and twenty cords of wood, divided by six, and that's a hundred and fifty-three years! Long live wood heat.

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