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Comment by credit_guy | Hacker News Reader

> which I was told was a bad thing, but now it actually doesn't really matter.

The average car in the US emits 350 g CO2 per mile [1]. The average American commute is 40 miles [2]. That's 14 kg of CO2 per commuter, or 14 million kilograms per 1 million commuters. So, about 14000 tons of CO2 per day, or about 5 million tons per year. 5 MT.

Every year the US emits about 5 GT of CO2 equivalent [3]. If a million people stop commuting right now, the US will reduce its emissions by 0.1%.

[1] https://www.energy.gov/eere/vehicles/articles/fotw-1223-janu...

[2] https://www.zippia.com/advice/average-commute-time-statistic...

[3] https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas...

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How about the reduction in emissions for all of the office spaces for every office in the US?

Office buildings tend to be much more efficient than homes. People who are not in the office work from home, where they use heating, air conditioning, lights, you name it. They don't just disappear from the face of the Earth.

What? Tons of people leave their HVAC on when they're at work, so that it's comfortable when they return. Now they're at home using it instead.

So the climate argument for working from home is "let me work from home, otherwise I'll live my home HVAC on when I'm at work, and that's bad for climate"?

Look, some people want to work from home, and it's good for a lot of reasons, but climate has nothing to do with that.

It does: transportation is about twice as large a source of emissions as all non-industrial commercial and residential activity. There's just no way not to be wasting a lot of energy when you're moving multiple tons of metal to move one person.

https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emis...

Since car commuting also correlates with other negatives, that seems like a good thing to try to reduce since there are very few downsides — someone giving up their commute is _happy_ about it, unlike a business being asked to stop using an industrial furnace or a farm being told they shouldn't truck in feed. Every bit we save in one area gives us more time to work on the others.

I'm not threatening anything, these are actual human behaviors that your cost analysis has to take into account when you say things like WFH has no meaningful impact on emissions. Running HVAC on every office in the US + daily commutes has a big impact, one that would completely vanish if office workers WFH.

> has a big impact

Big relative to what?

Let's run the numbers.

For a 2000 sqf home the AC consumes about 3-4 kW of electricity [1]. The vast majority of electricity in the US is produced with natural gas, where 1 kWh of electricity results in about 0.5 kg of CO2 [2]. Let's say 1 million people run the AC for 10 hours per day during the hot season, which is roughly 100 business days per year. That's 40 kWh per day, or 20 kg per person, or 20000 tons per one million people. Multiplying with 100 we get 2 MT of CO2.

Heating is probably similar. Obviously heating does not happen at the same time as AC, and people in the Southern states use more AC, and those in the Northern ones use more heating. Anyway, let's say heating adds another 3 MT of CO2, so overall the commute and the AC and the heating come to 10 MT of CO2 or 0.2% of the emissions.

[1] https://itlandes.com/how-many-watts-does-an-air-conditioner-...

[2] https://www.eia.gov/tools/faqs/faq.php?id=74&t=11

The savings would be on office heating and cooling, not home heating and cooling. You're calculating the wrong thing.

Also, I thought of another thing you should factor in: restaurants. They're incredibly wasteful with food. With no office workers, many restaurants (especially around offices) have drastically fewer customers. You'll need to include the carbon savings from some percentage of the food that goes to waste.

> You're calculating the wrong thing.

Yes, I was just being conservative. The savings on the office side would be much lower, because as I said, offices are more efficient than homes. Plus, most offices would not close if people work from home.

As for restaurants, you are going into second and third order impacts. Why not calculate the savings from all the dry-cleaning that doesn't happen because people can work in their sweat pants at home?

>As for restaurants, you are going into second and third order impacts.

Yes, that's what systemic change is, and you appear to be presuming (with your mocking jab about sweat pants, give me a break) that it's irrelevant to study second and third order effects of large social changes. That's not a very credible perspective to have.

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