Climate Impacts of Biking vs. Driving

You can&#x27;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.<p>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.<p>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.

Things the author failed to include in the study:<p>1) Road land use, a bike lane is narrower than a car lane.<p>2) The energy invested in building the car. Aluminium parts, which cars are made of, have very significant energy investments.<p>3) CO2 emissions of asphalt used to pave the roads that cars drive on.<p>4) CO2 emissions of the cars tires vs the bikes tires<p>5) Calorie consumption of the person driving&#x2F;riding in the car!!!!!!!<p>6) Parking land use.<p>7) Land use associated with mining the materials used to build a car vs bike.<p>8) Land use of pollution barriers to protect residential areas from car intensive ones.<p>9) CO2 emissions associated with heavy raised roadways made of concrete and steel, such as highway overpasses.<p>Basically, this analysis is laughably absurd and is an insult to the Harvard name.

It doesn&#x27;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&#x27;t they eating meat themselves? And the BP leak? How much km of cycling did that cost? This kind of study is completely bogus.

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

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

Can&#x27;t I just bike to school and feel good about it? Is nothing sacred?

In my city, they&#x27;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&#x27;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).<p>Without denigrating the need for bike safety and separated lanes, I really wonder about the numbers on the carbon trade-off there!

Actually, recent research shows that a vegetarian diet has higher impact on the environment than eating meat. It&#x27;s obvious too when you think about it. Consider how much lettuce you&#x27;d have to eat to replace the caloric content of one pound of beef. And there&#x27;s a lot of resources which go into farming vegetables.<p>On the whole it&#x27;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&#x27;d vastly lower our environmental footprint and increase air quality. Plus we&#x27;d all get more exercise. But, of course, the automakers are hugely invested in keeping us buying new cars and driving them.

I think the author is interpreting paleo as &quot;high protein&quot; whereas most people doing paleo are &quot;low&#x2F;no grain&quot;. 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)<p>I pretty much don&#x27;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.<p>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&#x2F;fish&#x2F;oil sources.

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.<p>Protein doesn&#x27;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.

While the article is clearly setting up the calculation in a very slanted way, I think the point they are making is still interesting.<p>I definitely don&#x27;t think this is (or even an attempt to be) an effective criticism of the environmental value of biking.<p>However, <i>even with</i> 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&#x27;ve clearly been underestimating the climate impact of meat consumption, and that&#x27;s interesting.

An electric scooter should beat all of those.

I&#x27;d bet that most people eating fast food meat probably aren&#x27;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!

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.<p>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.<p>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.