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> Small engine-based tools are a surprisingly large source of carbon emissions and air pollution... just one hour of gas leaf blower use is the equivalent of driving 1,100 miles

Perhaps this is true for certain types of air pollution, but there's no way it's true for carbon emissions. CO2 emitted has to be proportional to gasoline burned. And there's no way a leaf blower is consuming 25 gallons of gas per hour.

I’m not an expert in the chemistry at all but how does the 2-cycle oil added to the fuel contribute to carbon density of the fuel?

It's denser than octane but doesn't meaningfully close the gap.

To drive 1100 miles, the commenter above gave an extremely generous 25 gallons of gas (likely closer to 40 for a non-Prius).

One gallon of gas produces about 20 pounds of CO2, which is about 73% oxygen (from the atmosphere) by weight. The remaining 27% of the weight comes from carbon.

So, one gallon of gasoline provides 20*0.27=5.4lbs of carbon to the CO2 produced. Multiply by 25, and you're looking at over 135lbs of carbon alone coming from your source when 25 gallons of gas are burned.

Considering that the amount of weight carried around by the user of a leaf blower is on the low tens of pounds, and not hundreds, it seems ludicrous to presume that a leaf blower produces anywhere near the amount of CO2 in an hour as does a car driving 1100 miles.

It doesn't. This is about particulate pollution and other directly toxic nasties, not CO2 or climate.

It basically doesn't.

Even without the oil - 2-stroke engines will run on straight petrol, albeit briefly - they still emit an obscene amount of unburnt fuel.

I found a 2001 study that says 1 hour of lawn mowing is equivalent to 100 miles. either a mistype, wicked game of telephone or nefarious act has taken place. https://www.sciencedaily.com/releases/2001/05/010529234907.h...

No catalytic converter and it makes sense. It is talking about traditional pollution and not CO2.

Fixed link: https://www.sciencedaily.com/releases/2001/05/010529234907.h...

Yeah I am assuming that they are talking about the pollutants that are normally burned up in a catalytic converter. Still confusingly worded.

The source might be "A REPORT TO THE CALIFORNIA LEGISLATURE ON THE POTENTIAL HEALTH AND ENVIRONMENTAL IMPACTS OF LEAF BLOWERS" found here: https://ww2.arb.ca.gov/sites/default/files/2018-11/Health%20...

This is the table in the source:

  +--------------------+-------------------+-------------+---------------+
  |                    | Exhaust Emissions | New vehicle | Older vehicle |
  +--------------------+-------------------+-------------+---------------+
  | Hydrocarbons       | 199.26            | 0.39        | 201.9         |
  | Carbon Monoxide    | 423.53            | 15.97       | 1310          |
  | Particulate Matter | 6.43              | 0.13        | 0.78          |
  | Fugitive Dust      | 48.6-1031         | N/A         | N/A           |
  +--------------------+-------------------+-------------+---------------+

and the accompanying text:

> Another way to visualize the data is to compare emissions for a given amount of leaf blower operation to miles traveled by car. The Air Resources Board regularly publishes such emissions benchmarks. Thus, for the average 1999 leaf blower and car data presented in Table 9, we calculate that hydrocarbon emissions from one-half hour of leaf blower operation equal about 7,700 miles of driving, at 30 miles per hour average speed. The carbon monoxide emission benchmark is signficantly different. For carbon monoxide, one-half hour of leaf blower useage would be equivalent to about 440 miles of automobile travel at 30 miles per hour average speed.

For those not reading closely note that Hydrocarbons != Carbon. A New vehicle will burn fairly completely (if you include the cat as part of the process), leaving a miniscule amount of hydrocarbons (incompletely burned fuel) and a small amount of CO. The catalytic converter will oxidize hydrocarbons, CO and NO2 leaving almost entirely N2 CO2 and H2O (and in fuels with significant sulfer, hydrogen sulfide which has its own issues).

> New vehicle will burn fairly completely (if you include the cat as part of the process), leaving a miniscule amount of hydrocarbons (incompletely burned fuel) and a small amount of CO

So will old ones, if you run them on the right fuel.

My 25-year-old Range Rover has a 4.6 litre engine adapted to run on propane which is - under the right circumstances - a *negative* emission vehicle. It can have measurably less CO and HC in the exhaust than in the intake air (city air heavily contaminated with CO and HC for example from bus engines).

I've found in general people and even regulatory agencies play fast and loose with comparing GHGs and pollutants. In this case, including CO in "carbon emissions" makes the statement technically true but pretty misleading since most people see "carbon emissions" as an equivalent or shorthand to "GHG ermissions"

The person you are replying to did not mention gas (just lead blowers in general) but your post seems to only focus on gas leaf blowers. California did not ban electric leaf blowers did they?

Electric leaf blowers are annoying, but not burning fuel with zero emissions controls such that gas landscaping appliances are, hence bans on the gas versions causing wild amounts of pollution for the amount of fuel burned.

There is a reason combustion vehicles are mandated to have a catalytic converter, and why diesel vehicles must filter particulates.

What’s the difference between electric and gas leaf blowers with regard to particulate matter in the air?

The gas leaf blower also is also burning gas, and hence adding that particulate matter in addition to what gets stirred up.

It's not just burning gas; as a 2-stroke engine, it's burning a gas/oil mixture that is even dirtier than burning just gasoline.

That makes sense. I am curious as to how big the difference the power source makes for a machine that’s purpose-made to kick up particulate matter up into the air from the ground.

2-stroke engines in general are awful for air quality.

https://phys.org/news/2014-05-two-stroke-scooters-super-poll...

I believe that! I am curious as to how big the difference the power source makes for a machine that’s purpose-made to kick up particulate matter up into the air from the ground though.

Did anyone imply there was a difference (besides electric ones possibly being less powerful)?

If you scroll up this thread you will see where the discussion began.

Edit: For example, you’ll see where I asked my initial question here

https://news.ycombinator.com/item?id=36501689

Purely anecdote, but my neighbor uses a gas leaf blower and we use an electric one, and our yards are broadly similar. The difference is notable.

How?

The electric blower yard probably still has leaves on it.

I'm all for electrifying yard tools, but electric blowers still aren't anywhere near a high end Stihl or Husqvarna in performance.

We both kick up a fair amount of fines, but there's also a noticeable amount of fairly dirty output from the gas blower.

It's in that CARB report posted above: https://ww2.arb.ca.gov/sites/default/files/2018-11/Health%20...

Compare Table 3 to Table 5. PM emissions from exhaust are on the order of 1 gram per hour. Whereas fugitive dust emissions, depending on the surface, are 100s or 1000s of grams per hour.

I found a CARB report[1] that addresses this. TL;DR: nobody's directly measured the particulates ("fugitive dust") kicked up, but the estimates made from back-calculating measurements of dust present on road services suggest that the majority of PM10 and PM2.5 from a leaf blower are due to fugitive dust, and therefore will still be present in electric leaf blowers.

There isn't a lot of data on how much the chemical makeup of particulates affects health, nor on what the makeup of particulates likely to be kicked up by a leaf-blower are. At least some of the particulates from two-stroke engine emissions are known to be really bad (e.g. partially combusted lubricants). So the jury is out on if the particulate related health risks are dominated by the engine or the dust. If you think "all PM2.5 is bad" then it's almost certainly dominated by the dust though.

1: https://ww2.arb.ca.gov/sites/default/files/2018-11/Health%20...

Thanks!

a bunch of nitrogen oxides that are pretty bad for people, a bunch of Co2, and a bunch more noise.

Even if gas leaf blowers weren't terrible as far as emissions they are a weekly menance for apartment dwellers so I am hoping they will be banned where I live eventually. Electric is somewhat annoying but tolerable.

A complex pays for regular landscaping services which turns into hours of painfully disruptive noise pollution often in the early hours for residents.

Electric blowers are still very loud and high pitched. My dream is an electric backpack blower with a giant squirrel cage blower powered by a low rpm brushless motor, instead of the high rpm blade fan blower like in my current handheld tool.

Ego commercial blower: 170mph 600cfm (only during turbo boost, unclear how long that can last)

Stihl gas blower: 239mph 912cfm

Not even getting into weight, cost, or refuel times - that's extremely far from parity.

> electric landscaping tools are at parity

For most homeowners. Not for commercial usage. There's that battery charge issue still. There are workarounds that can help though.