
Climate Impacts of Biking vs. Driving - JonSchneider
http://keith.seas.harvard.edu/blog/climate-impacts-biking-vs-driving
======
alephnil
You can't turn off the body, and you need exercise to stay healthy. Thus it
does not really make sense to compare cycling to driving like the article
does. If you are driving to the gym, and then using the energy you would have
used biking at the gym, you will cause the combined emissions of both cycling
and driving. The only way to get away from that is to be more passive, so that
you would require less food, and thus cause less emissions. That is hardly an
attractive option.

It is better to start with the most avoidable emissions first. Driving is
obviously more avoidable than respiration, and coal fired electricity
generation is likely even more avoidable. After that the next step will be to
reduce the CO2 footprint of food production as well as changing to a diet with
lower CO2 footprint.

Comparisons like the one in the article only give the message that it is
really nothing you can effectively do about climate change, so why not
continue as usual.

~~~
ysea
Precisely, I either bike or bus to work every day. If I take the bus I do some
other form of exercise instead. And I certainly don't eat less on the days I
ride the bus. I would imagine most people that get around by bike maintain a
steady level of exercise during times when they are biking less.

Whether or not the author's intent was to discourage biking and encourage
driving they have done exactly that.

~~~
sonthonax
I run 8 miles to work a few times a week. I still shock my colleagues with how
much I eat those days.

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timthelion
Things the author failed to include in the study:

1) Road land use, a bike lane is narrower than a car lane.

2) The energy invested in building the car. Aluminium parts, which cars are
made of, have very significant energy investments.

3) CO2 emissions of asphalt used to pave the roads that cars drive on.

4) CO2 emissions of the cars tires vs the bikes tires

5) Calorie consumption of the person driving/riding in the car!!!!!!!

6) Parking land use.

7) Land use associated with mining the materials used to build a car vs bike.

8) Land use of pollution barriers to protect residential areas from car
intensive ones.

9) CO2 emissions associated with heavy raised roadways made of concrete and
steel, such as highway overpasses.

Basically, this analysis is laughably absurd and is an insult to the Harvard
name.

~~~
maxerickson
The recent Ford F-150s with aluminum bodies were huge news. The frame is still
steel.

Personal vehicles are mostly made of steel.

~~~
timthelion
And steel actually produces even more CO2 to cast. Carbon steel, melting point
1500C vs aluminium, just 600C. [http://www.engineeringtoolbox.com/melting-
temperature-metals...](http://www.engineeringtoolbox.com/melting-temperature-
metals-d_860.html)

~~~
maxerickson
The specific heat is also important, not just temperature.

You also have to look at refining (it takes a huge amount of energy to produce
raw aluminum) and recycling (steel is really, really recyclable).

~~~
timthelion
Well they both take more energy to cast than my average bowl of mashed
potatoes and peas that's for sure!

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d--b
It doesn't count what the impact of extracting gasoline is, or the effect of
transporting it on a supertanker. And what about feeding all those people
working in the oil industry? and the energy used by lobbyists to convince
people to drill in Alaska. And aren't they eating meat themselves? And the BP
leak? How much km of cycling did that cost? This kind of study is completely
bogus.

~~~
gbrown
Not to mention whether exercise is substituted. What about a driver who runs
on a treadmill, or does some equivalent amount of exercise without getting
transportation in return?

Plus, did I miss something, or was food not counted as a renewable resource?
While agriculture is not carbon neutral, it's also not a 100% carbon source.

~~~
jogjayr
Not to mention that all the additional biking will improve people's health,
thereby reducing the costs (and emissions) of healthcare and medication.

~~~
InitialLastName
Last I heard, the jury was still out on costs of obesity care vs old age care.
Anyone have an update?

~~~
jogjayr
There's an argument to be made that people who are healthier throughout their
lives will be able to have a higher quality of life, and need less care, well
into old age. So even if they live longer it might not cost as much in old age
care. But you're right that that's more of a gut-feeling/heuristic kind of
thing. We'd need actual numbers to know for sure.

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ABCLAW
The Keith Group, responsible for the article, are an academic group advocating
the use of solar geoengineering (aka, putting aerosols and solar shades up to
stop global warming, rather than focus on carbon sequestration).

This weak attempt to indicate that transport choices do not substantially
change carbon emissions is in line with their pre-existing position.

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lyle_nel
Emissions of CO2 on its own does not necessarily imply that there is a carbon
footprint.

Besides the carbon footprint of transporting food, the food we consume is
carbon neutral since the carbon in the food comes from the atmosphere.
Therefore the CO2 gas we expel is mostly carbon neutral.

Cars are a different story since their carbon originates from ancient
reserves(oil and coal) that has long since been removed from the carbon cycle.
This carbon is now reintroduced to the carbon cycle, thus leading to a
positive carbon footprint.

Put differently, if our food we eat consisted of carbon extracted from oil or
coal, then we would be adding CO2 to the current carbon cycle, thus leading to
a positive carbon footprint. However this is not true.

~~~
wlesieutre
Oh but there's so much more energy in your food. There's the energy that went
into producing fertilizer, energy to make pesticides, energy burned to run
tractors, energy to process the harvest into what you get in the grocery
store, potentially more energy involved in packaging. For plastic packaging,
there's the oil used to make the carbon-rich polymers. Etc.

Just like cars, all of that energy comes from burning fossil fuels. The only
way you'll find carbon neutral foods is if you walk out in the woods, pick it
off a wild plant, and eat it right there.

Generally, the total energy that goes into producing and transporting
something is called "embodied energy." It's not necessarily 1:1 related with
carbon footprint since it can hypothetically come from renewable energy
instead of fossil fuels, but it's a very related concept.

[https://en.wikipedia.org/wiki/Embodied_energy](https://en.wikipedia.org/wiki/Embodied_energy)

~~~
jbmorgado
Most of what you just said would actually reflect pretty badly on vegan diet
values and improve paleo diet values.

Vegan diets are the product of intensive agriculture basically anywhere in the
world. Paleo, depending on country, can be pretty low intensity, for instance,
in Argentina where cattle roams free in the grassland.

While I easily concede that in places like most of the USA - where cattle is a
product of intensive livestock exploitation - a paleo diet will produce a lot
of CO2 compared to a vegan diet, that is actually not true in places like
Argentina, or, to a lesser degree, in places like southern Europe.

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techman9
Can't I just bike to school and feel good about it? Is nothing sacred?

~~~
heydenberk
You can and you should! Carpooling in a very gas efficient car compares
favorably to biking with the most CO2 intensive diet. Biking wins in all other
cases. Also, if you don't eat an additional calorie for every one you burn
while biking — I know I tend to burn off winter weight when biking around in
the summer — these calculations are less applicable.

~~~
wapz
The article didn't mention a _lot_ of other factors. If you drive to work you
might go to the gym after work to burn the same calories the cyclist burned.
Then you'd consume the same extra calories he did. Not only that, but the
cyclist wouldn't have to go to the gym so they wouldn't even put in those
miles.

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squidfood
In my city, they've just taken some two lane roads down to one lane and
eliminated car turning lanes, to add bike lanes. Those bike lanes see maybe 1
bike every 15 minutes, while the cars are now significantly more backed up
(I've noted an extra 5-10 minutes of idling to travel a mile during busy
times, no idea how many cars total in a day).

Without denigrating the need for bike safety and separated lanes, I really
wonder about the numbers on the carbon trade-off there!

~~~
Analemma_
To some extent, that's working as intended. If bike lanes reduce throughput
for cars and decrease their utility, that pushes people towards using means
other than cars, even if that doesn't mean biking.

~~~
squidfood
Except: I don't see any evidence that it has worked at all - at least not in
the 2 years the lanes have been there. Nice idea, but data would be nicer.
(aside: always nice to see downvotes for wanting observations and data - if
the data belies my observations, I'm all for that).

~~~
timthelion
This really comes down to a "moral health of the citizenry". In Germany and
the Netherlands these programs work. In the US, less so. If you were to take a
%100 data based approach, and not take into account the choices of people, you
would no longer be studying sociology but rather mind control. If you have a
way, that actually is effective at changing peoples behavior, regardless of
what the people want then that is mind control. Do you think that mind control
is what we need in order to fight global warming, or do we just need to become
better people?

~~~
squidfood
In this city's case, they've dragged their heels on public transport - nothing
near what I found in Amsterdam, for example. Slowing down car drivers by 5
minutes will not get them to switch to the public transport that would add 30+
minutes. Include better public transport, and more people would switch. But
throwing up obstacles without providing alternatives doesn't do the job (and
based on my city, there would have to be some mind-control to get more public
transport funded, unfortunately).

~~~
timthelion
This is a difficult one. The selfish behavior of Americans does seem to be
causing a real world crisis. Per capita, a few countries (the middle east and
the US) produce significantly more CO2 emissions per capita than the rest of
the world [1]. This is expected to cause everyone significant problems and is
already taking a major toll on the forestry and fishing industries. Theres not
a lot that the rest of the world can do to put pressure on the US. A war would
only create more polution and wars suck. Trade embargos are difficult given
the US's geopolitical possition. This may well be, in the end, a tragedy
situation of game theory in which everyone loses and there is no way out.
There is no real way to privatise the atmosphere to get rid of the tragedy of
the commons going on there.

It actually kind of reminds me of the old "nuclear deterent" theory. The idea
that if you attack me, I'll create nuclear armagedon. If there was a way for
Germany to produce so much CO2 that everyone would die, then maybe Germany
could tell the US, "if you don't stop producing CO2, we'll produce a lot of it
ourselves". Really, I don't know though. So far, I'm not optimistic.

[1]
[https://en.wikipedia.org/wiki/List_of_countries_by_carbon_di...](https://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions_per_capita)

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laughfactory
Actually, recent research shows that a vegetarian diet has higher impact on
the environment than eating meat. It's obvious too when you think about it.
Consider how much lettuce you'd have to eat to replace the caloric content of
one pound of beef. And there's a lot of resources which go into farming
vegetables.

On the whole it's clear to me that of we could get the vast majority of
commuting traffic to turn into cycling traffic, or non-traffic (get more
people working remotely) then we'd vastly lower our environmental footprint
and increase air quality. Plus we'd all get more exercise. But, of course, the
automakers are hugely invested in keeping us buying new cars and driving them.

~~~
wapz
You can't compare caloric content of lettuce to that of beef. Vegetarians
don't stock up on lettuce to get calories. That being said, if every single
person was vegetarian, I would bet we could get the efficiency of vegetable
farming to beat the current efficiency of cattle through indoor farming.

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VLM
I think the author is interpreting paleo as "high protein" whereas most people
doing paleo are "low/no grain". Some people focused primarily on trendiness
seem to insist their low carb diet is paleo no matter how heavily processed
and weird it is (like those weird soy bar things)

I pretty much don't eat grains but almost certainly vegetables are more energy
intensive than grains so maybe my paleo salads are killing the planet almost
as well as the vegans eating processed soy products and baked wheat products
all day.

Then again no matter how thinly you slice it theres not a lot of calories in a
carrot so even if volumetric intake looks near vegan most of my calories might
be coming from meat/fish/oil sources.

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millettjon
This completely ignores the fact that grain fed factory cows are a problem but
pastured cows actually store carbon in the grass roots and also reduce
emissions by not tilling, and using less fossil fuels, fertilizers, and
herbicides.

Protein doesn't directly fuel exercise. Most people on paleo type diets target
a specific number of grams of protein for muscle maintenance and use carbs or
fat to fuel the exercise. So biking more distance would mean eating more rice
or potatoes or coconut oil for fuel. So the CO2 impact of the biking calories
would be similar to the vegan levels.

~~~
thinkmilitant
As someone who has been shifting their diet over to vegetarian for
environmental reasons, I am interested in this. Can you provide any support
for your claim that pasture cattle are less damaging then factory cattle?

I know that pasture raised cattle are not sustainable to feed the masses, but
at this point I would just be glad to enjoy a guilt free steak every now and
again. ;-)

~~~
dakrootie
I don't know if this answers your question, but do read The Vegetarian Myth
when you get a chance. It is one of the most profound and wonderful books I've
ever read about the subject of sustainability/ethics for vegetarianism vs.
omivoreism. Lierre Keith, while rather radical, makes a beautiful argument as
to why meat (in moderation and humanely raised) is preferable to a veg-only
diet. This is one of the top five books that's changed the way I see the
world. Cheers!

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anon_d
While the article is clearly setting up the calculation in a very slanted way,
I think the point they are making is still interesting.

I definitely don't think this is (or even an attempt to be) an effective
criticism of the environmental value of biking.

However, _even with_ a biased setup like this, the fact that the numbers can
be massaged into the same ballpark really shatters my intuition here. I think
my take-away is that I've clearly been underestimating the climate impact of
meat consumption, and that's interesting.

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Animats
An electric scooter should beat all of those.

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sixstringtheory
I'd bet that most people eating fast food meat probably aren't commuting by
bike. You can do both at the same time with a car, though, and burn fuel
waiting in line at the drive thru to boot!

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antisthenes
As always, the practical, dirty, coal-using, environment neglecting China is
way ahead in practice than the Boston PhD theorists funded by billions of old
US money.

This is a solved problem: you generate electricity via Solar and commute via
electric bike, lowering kcal consumption and increasing average speed and
range at the same time.

The problems are cultural and infrastructural - it needs a critical mass of
cyclists to become safe to ride electric bikes in the US, otherwise you risk
being run off the road by the majority of drivers who are distracted using
their phone.

~~~
sonthonax
Phone use while driving needs to be cracked down on though draconian measures
like roadside flogging.

~~~
InitialLastName
I'm almost convinced that if I see a driver looking at their phone while
moving (the absolute lowest standard of "don't use your phone and drive"), I
should be able to put my U-lock through their window. It's only fair to add to
their cost enough to offset the extra risk they cause me.

~~~
sonthonax
If you enjoy occasionally bullying idiots who drive with their phones, do it.
The police won't care, and there would not be enough evidence to prosecute you
anyway if you obscure your face with.

The person in the car won't understand why you've done it, and will get all
uppity and defensive, but will probably be jarred enough by the assault on his
or her personal space to make stupid mistakes throughout the day.

