[radicaledward]

I think a lot more goes into making urban life better for the environment than just cars. Off the top of my head I would expect the following to contribute:

Suburban heating and cooling involves larger spaces for less people (houses being bigger in the suburbs),

In an urban environment, there is a lower environmental cost for transportation and processing of food/water/other goods (fewer locations to deliver to).

In an urban environment, I would expect fewer materials are needed to maintain infrastructure (power lines, water pipes, roads, etc). Manufacturing all of these parts involves an environmental cost.

Suburban living currently almost certainly means a big lawn. Traditional green lawns are bad for the environment.

Urban communities can also centralize waste disposal and (I suspect) more easily implement recycling programs.

Finally, don't forget that an electric car is only actually better for the environment if the electricity is produced sustainably (this is mostly not the case in the US). I suspect that electric cars may actually be worse for the environment if powered by most US power plants.

[toomuchtodo]

> Suburban heating and cooling involves larger spaces for less people (houses being bigger in the suburbs),

Shouldn't matter as long as your dwelling is properly insulated.

> In an urban environment, there is a lower environmental cost for transportation and processing of food/water/other goods (fewer locations to deliver to).

I concede this point, although moving trucks to cleaner fuels will resolve this.

> In an urban environment, I would expect fewer materials are needed to maintain infrastructure (power lines, water pipes, roads, etc). Manufacturing all of these parts involves an environmental cost.

This is mostly a sunk cost with existing suburban and rural infrastructure.

> Suburban living currently almost certainly means a big lawn. Traditional green lawns are bad for the environment.

No disagreement, although you're not required to have a lawn. You can cover the whole area with rock or a garden (I know several people who do either).

> Urban communities can also centralize waste disposal and (I suspect) more easily implement recycling programs.

My local suburban trash service uses methane from the local landfill to power its vehicles, and in due time will switch to electric vehicles.

> Finally, don't forget that an electric car is only actually better for the environment if the electricity is produced sustainably (this is mostly not the case in the US). I suspect that electric cars may actually be worse for the environment if powered by most US power plants.

This was the point I was most interested in responding to. In all cases, electric vehicles are better than petroleum vehicles, even if powered by fossil fuel generation sources. Its much simpler to maintain emissions controls on one coal plant than 100K cars. Also, your fleet gets "cleaner" as renewables and other clean energies come online, whereas your petroleum-powered vehicles will always burn petrol for the life of the vehicle.

[radicaledward]

> Shouldn't matter as long as your dwelling is properly insulated.

I realize that neither of us are citing sources, but I'm pretty sure you are wrong about this. I don't want to spend too much more time on this response (I wrote the other bits first). So I'll leave it at that.

> I concede this point, although moving trucks to cleaner fuels will resolve this.

It could mitigate some of this, but definitely not all of it. Resources will still be spent on replacing worn parts or entire trucks in the fleet. Expending resources will always have some negative effect on the environment.

> This is mostly a sunk cost with existing suburban and rural infrastructure.

I said maintenance not construction. Infrastructure decays incredibly quickly. We are constantly replacing and upgrading our infrastructure. Power lines go down in storms. Water pipes get broken as the earth settles. Roads are repaved or rebuilt constantly.

> No disagreement, although you're not required to have a lawn. You can cover the whole area with rock or a garden (I know several people who do either).

Fair enough.

> My local suburban trash service uses methane from the local landfill to power its vehicles, and in due time will switch to electric vehicles.

Ok, but that doesn't mean it wouldn't be easier (cheaper and less resource intensive) to ramp up such services for the same number of people if those people are living at a higher population density.

> This was the point I was most interested in responding to. In all cases, electric vehicles are better than petroleum vehicles, even if powered by fossil fuel generation sources. Its much simpler to maintain emissions controls on one coal plant than 100K cars. Also, your fleet gets "cleaner" as renewables and other clean energies come online, whereas your petroleum-powered vehicles will always burn petrol for the life of the vehicle.

I seem to be thinking about completely different sources of environmental damage from you. My understanding is that 1) the majority of the environmental costs from cars actually comes from new car production, not from fuel consumption. 2) Electricity distribution is inefficient enough that it requires a disproportionately large amount of coal to power a car when compared to the petrol used to drive the car the same distance. 3) Electric car batteries are composed of materials that must be mined, which carries its own environmental costs.

For the record, I didn't downvote you. I don't downvote people just because they disagree with me. I also don't have downvote privileges on this site anyway. I'm enjoying the discussion and I hope that you are too!