[dwaltrip]

Electric vehicles can run off carbon neutral sources. They can take advantage of any future improvements in electrical power generation and storage. It is literally impossible for ICE vehicles to be carbon neutral.

Solar and wind are already becoming more profitable than running existing coal plants in some areas. Market forces in tandem with continued technological development will accelerate these shifts. It would also be prudent for government to nudge this process along.

[dragonwriter]

> It is literally impossible for ICE vehicles to be carbon neutral.

No, it's not. ICE doesn't care if the fuel is manufactured from fossil sources (which isn't carbon neutral) or from biomass by thermal depolymerization or other means, which can be carbon neutral.

[AstralStorm]

Growing biomass is carbon neutral, burning fuel derived from it never is.

Thus even bioethanol is not carbon neutral unless used in chemistry where it's not burnt.

[dragonwriter]

> Growing biomass is carbon neutral,

No, growing biomass sequesters carbon.

> burning fuel derived from it never is.

Burning fuel derived from biomass releases the carbon sequestered in growing it. So, the whole process is carbon neutral.

(Yes, that means fossil fuels are carbon neutral viewed over the entire time window from when the biomass from which they were derived was grown. They aren't carbon neutral over the timescales we care about, but anything derived from recent and sustainable biomass production is.)

[DuskStar]

Growing biomass is carbon negative, burning biomass is carbon positive. If you combine the two, and your biomass production process doesn't itself require carbon releases (fertilizer, diesel for farm equipment, etc) then the entire process can be carbon neutral.

[tonyedgecombe]

We are a long way from making our energy carbon neutral. The UK is often cited as being ahead yet all we have done is pick the low hanging fruit. Dealing with the rest is going to get increasingly difficult and expensive.

If you are really serious about lowering your carbon impact then you will be visiting the bike shop rather than car showroom.

[londons_explore]

Bicycling isn't as low-carbon as you expect. 10 bikes ~= 1 car as far as CO2 per km is concerned. Running on foot is about the same CO2 per mile as a car with one passenger, and obviously a car with more than 1 passenger works out much better than running.

It's all down to the fact that if you exert yourself, you'll need to eat more food, and food production is very CO2 heavy.

[njb311]

While it is absolutely true that cycling and running produce CO2 emissions, the figures I found for running "at a very challenging pace" equate to 54g per mile above normal respiration [1], so even with two people in a car (especially driving in urban areas) running would still produce less than most cars on the road today. Of course, there are other factors involved.

Stated tailpipe/windpipe emissions don't include the carbon cost of production for either fuel or food. That will depend on your diet, where in the world you live, where food or fuels are grown/extracted, where/how they are processed and transported, and so on. The environmental impact of production can also cause CO2 emissions long after production through land use change, land remediation, etc most of which is not accounted for when making these comparisons even if a "full" LCA is undertaken.

The carbon cost of manufacturing a car is rarely quantified but I remember one maker estimated it was the equivalent emissions of driving 40-50,000 miles. A bicycle is far less and lasts far longer (I've had my bike for 23 years and it's fine). And of course, that's just the manufacture. Car maintenance also has a much greater carbon impact than a bicycle or replacing the soles for your shoes.

We also have a fairly crazy situation where people drive to work or other places, but then go for a run or go to the gym to burn calories and 'get fit' – perhaps even running on a treadmill which itself consumes energy. Just the idea that you have excess calories that you need to undertake an activity specifically to burn them is a counter to the argument that walking or cycling more would lead to increased food intake. Of course, I know that some people go to the gym to do resistance training targeting physiological benefits.

But then again, the obesity epidemic also demonstrates that excess calories (exacerbated by shifts in the make-up of diet) is an existing problem.

[1] https://www.livestrong.com/article/524672-what-effect-does-e...

[poiuyt098]

> It is literally impossible for ICE vehicles to be carbon neutral.

Biodiesel and [m]ethanol fuels are a real thing.

[AstralStorm]

These are not carbon neutral, a vehicle emits CO2 when burning them and that is not captured even in half by the growing plants.+

And you have to fertilize them for this efficiency, and those either require non-neutral manufacturing process, or composting which releases methane (in itself a biofuel that could be used but isn't). Plants also release some methane on their own when growing.

That's not even counting loss of biodiversity or replacing carbon-negative fields, farming grasslands and forests.

You could make a biofuel carbon neutral but we're not even close. Bioethanol for example has a CO2 producing fermentation step. Going biohydrogen and burying the plants could work. (Even methane is not clean enough to offset planting, unfortunately.)

And we do not want to go neutral but to reduce emissions.

-- +) The number is 37% according to in-depth study: http://theconversation.com/biofuels-turn-out-to-be-a-climate...

[poiuyt098]

I'm not here to pettifog about various definitions, studies and calculation methodologies. "Literally impossible" was claimed but now requires, uh, interpretations.

https://en.wikipedia.org/wiki/Carbon-neutral_fuel

[dwaltrip]

Fair point, that slipped my mind.

Electric vehicles are far more promising and compelling as a large scale solution to replace most existing consumer ICE transportation, but there are probably some roles for ICE vehicles using carbon neutral fuels.

[_Microft]

The problem with ICEs is not that they emit carbon dioxide but that the fuel they use is from fossil sources. This adds additional carbon into the carbon cycle which was 'locked away' for millions of years but is now re-introduced into the shorter term carbon cycle with all the effects that has.

So theoretically one could have carbon neutral ICEs by not using fossil fuels, which could be sourced by converting carbon dioxide into fuel:

https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_proces...

I don't think that this is a reasonable thing to do though. Go electric instead. Producing and transmitting electricity is easier and also more flexible as different sources (solar, wind, hydro, nuclear...) can be used.