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Comment by phnofive | Hacker News Reader

The headline claim as laid out in the article:

> we found that emissions from cycling can be more than 30 times lower for each trip than driving a fossil fuel car, and about ten times lower than driving an electric one

Assuming we’re comparing single occupant passenger vehicles to bicycles (incl. e-bikes), this seems fairly self-evident and hardly actionable.

> We observed around 4,000 people living in London, Antwerp, Barcelona, Vienna, Orebro, Rome and Zurich.

> [...]people who walk or cycle have lower carbon footprints from daily travel, including in cities where lots of people are already doing this.

Okay, again, big surprise. Where that infrastructure exists to support such a move in dense cities, abolishing private car ownership would surely have some climate impact, but can we quantify it any better than .03x of ‘?’?

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Why isn't this actionable? We are currently making significant public and private investments into electric cars based on their reduced emissions. Why not also invest in cycling infrastructure (beyond the very limited capacity that most US cities are currently doing)?

There is no evidence to suggest millions of bicycle commuters are waiting in the wings for more green paint.

I am. Cycling in the city is dangerous.

Aren't there studies that show the health benefits out weigh the dangers? I think the problem is more that it feels more dangerous and is, as a result, is often quite stressful.

That's the sort of comparison you can only make over the entire population. Looking at it from the perspective of an individual, it's a raw deal if my general fitness is improved but then two years later I get hit by a car and walk with a limp for the rest of my life.

I do bike commute and lived in Seattle for 7.5 years without a car.

There is plenty of evidence from many cities around the world. Copenhagen is a rather famous example, their turnaround from being very car-centric to being very bike-friendly started in the 70s IIRC, and the transit patterns followed as planned.

There actually is pretty significant evidence:

https://www.nytimes.com/2021/04/01/climate/bikes-climate-cha...

https://www.pnas.org/content/118/15/e2024399118

https://www.nctr.usf.edu/wp-content/uploads/2013/12/jpt16.4_...

https://www.sciencedirect.com/science/article/abs/pii/S22136...

https://www.nar.realtor/blogs/spaces-to-places/bike-lanes-bu...

https://tfl.gov.uk/info-for/media/press-releases/2011/januar...

(although you might be correct about green paint, thats fake infrastructure and paint won't protect people from getting hit by cars)

When it comes to transportation infrastructure, you certainly don't want to plan the future based on apparent present demand. Los Angeles vs Copenhagen is a great comparison of the results of continually building for what people seem to want "now" (in the former case) versus building to create a better future.

LA actually has decent public transportation now, and it's getting better. it's also the perfect city for biking, with lower temperature variances, elevation variances, and precipitation rates than most cities. we just need to convert on-street parking into bike lanes everywhere, and we'd be all set (with protected lanes built out over time).

LA may have been the poster child of poor planning in the 80's, but i'd suggest cities like phoenix, houston and atlanta have surpassed it in that regard.

Agreed, the city has made a lot of progress. I was indeed thinking of its planning for most of the 20th century!

As they say, the power is in the marginal consumer. There are people who, given more bicycle infrastructure, will be helped over the threshold to riding a bicycle for more trips (I'm one of them; I will commute by bicycle, but the roads around me don't make riding home from a store with a trailer a safe decision).

Also, painting more lines on a road is usually more of a half-hearted municipal response to requests for bicycle infrastructure; the changes that are established to improve ridership are physically separated bicycle lanes, the network effect of more cyclists, and holding drivers responsible when their behaviors kill or maim more vulnerable road users.

Not green paint, but safe cycling infrastructure would absolutely convert my girlfriend to a cyclist.

The amount of people who call me insane for cycling on London roads is no joke.

Because most US cities are not compact and flat as Copenhagen

ebikes, though a bit more expensive, make getting over the hills in even SF doable

SF is a very compact city (7 miles across)

I'm not willing to spend thousands on an ebike while living in a city where I expect my bike to be stolen at least once a year.

(and all of my bikes that were stolen, were stolen out of locked garages!)

Even 1 bike per year isn't that bad if you have insurance, car maintenance + depreciation is probably more. Not to mention when your catalytic converter gets stolen.

eBikes definitely help with the topography issues ( Seattle , Pittsburgh ). You still have the sprawl and separated land use patterns in a lot of cities though.

Of course summer commuting in Houston or Phoenix is going to suck no matter what your bike is

Don't ebikes bring in a lot of the enviromental concerns as an electric car? Less for sure, but it probably starts to close that 10x number.

The cycling rate in Århus Denmark is almost as good as Copenhagen and it's quite a hilly city.

Today, they aren't. But we could and should alter zoning laws to encourage density.

Millions numbers of people live in urbanized flat valleys in California (Oakland, San Jose, Redding, Sacramento, Fresno, Bakersfield, parts of LA/SGV/Inland Empire/OC).

I have a multi-city dedicated completely separate from traffic bike path that would take up 90% of my bicycle commute distance but I still drive to work because the last 2 miles to get into the office involves mingling with high speed traffic, broken glass, trash, illegally parked cars and my favorite: "SHARE THE ROAD" signs.

Doesn't this suggest that cities should continue to build out their bike infrastructure? You can't get high bike use without protected lanes / etc.

I don’t get it where is the emission coming from bicycle trips?

I would assume from the manufacture of the bicycle.

Really? Manufacturing a bicycle has only 10x lower carbon footprint than manufacturing an electric car? Doesn’t sound logical to me.

I guess you have to eat a bit more if you ride more, I certainly notice when I bike to work (5mi each way, 300ft climb) that I need to eat a bit more food. Certainly no where near the energy of a car though but its not zero. Assuming you want to maintain your weight.

That’s a strong assumption. I for one wouldn’t eat less if I stopped biking. I commute to work, do shopping and go everywhere by bike throughout the year. I don’t own a car.

Just my experience. I stopped biking to work due to COVID and I eat less than before. I tried to just go for a 5mi ride in the morning but I'm not motivated w/o the commute and just take the dog for a walk instead.

Are you saying you have a mythical body that burns no calories when biking? Or are you saying you'd be willing to gain more weight because you'll never change your diet?

It's interesting because the food you eat makes a big difference then on your commute. A diet high in beef or fresh fruit could actually make your commute WORSE than an electric car.

Biomass is not a particularly low emissions energy source.

The bike does need energy to move.

True, but adults need around 30 mins exercise per day anyway so we can take the carbon budget from that.

> vehicle life cycle emissions considered emissions from the manufacture of vehicles, with aggregate carbon values per vehicle type (cars, motorcycles, bikes and public transport vehicles) derived assuming typical lifetime mileages, mass body weights, material composition and material-specific emissions and energy use factors.

and

> The observed e-bike share was 4.5%; therefore, average emissions include 4.5% e-bike, 95.5% normal bike.

It’s not totally clear to me if the emissions required to produce the energy the human burned to power the bicycle are included—it would certainly vary quite a bit based on the food.

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