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36

I’ve already touched on this topic on the sister SE site once or twice. To summarize what is told there (check for more detail), there would be several considerations as related to energy use and sustainability: Idling in itself wastes fuel for no good reason, and that adds up. In US (country whose residents drive probably more than anyone else on Earth, to ...


25

This is a really big question, and @EnergyNumbers' answer addresses some of it. I'll try to address some more. Battery End-of-Life Your question is obviously referring to standard car batteries, which are used to power the car's starter motor. These are generally lead-acid batteries. A true Electric Vehicle (EV) may have a small battery just like this ...


21

This question is addressed in a paper by Shibahara et al, 2013. They don't discuss walking, but they do discuss bicycling, which I suppose is a more realistic method for commuting (for example, I bike the 8 miles to work but I've never walked it). The authors analyzed taxi, gas cars (GV), electric cars (EV), bus rapid transit (BRT), light rail (LRT), city-...


20

EVs offer some definite advantages, and lots of advantages that depend on the specifics. short answer: yes, it's better than driving a fossil-fuel car. Long answer: it may seem to make less sense if you only consider a very small range of impacts, where all of the costs are visible, but only some of the benefits. Only when you zoom out to the long-term ...


19

Long question, short answer: No. There is nothing like an universal database on carbon footprints or similar. Of course there are a lot of websites which allow you to calculate the impact of - for example - travelling by plane or by car. But the actual calculation of such values is very complex and always comes along with a lot of research. You mentioned ...


18

So the short answer is to look at 'life-cycle assessment' studies (LCA). The longer answer is to ask what you mean by 'better', and then look at a bunch of LCAs and figure out what impact categories you care about most. In either case, the goal of LCA is to collect all the different inputs and outputs for a product for all stages - not just use, but ...


15

Several factors come to mind Air-conditioning Probably one of the bigger factors for saving fuel. At low speeds, open the windows instead (if it's hot); close the windows & wear a jacket (when it's cold). For high speed, close the windows, even when it's hot. At higher speeds the drag created by open windows uses more fuel than the air-conditioning. (...


14

TLDR: in this particular case, where the buyer lives very close to the shop, it's likely that buying in a brick-and-mortar shop has a lower carbon footprint compared to buying online. Online shopping may become greener when the distance to the shop is more than 14 - 50km (depending on your shopping behavior and on which scientific study you consult). I ...


13

Let's assume that the use of fuel is the key factor to contribute to global warming and identify four ways that an individual can choose to cross the Atlantic ocean: Large passenger ships, small passenger ships (sailing boats), large cargo vessels and airplane. Fuel use per transport mode Here are the km a given transport mode delivers per one litre of ...


12

If we diverge slightly from the request for CO_2 per passenger km, and look at energy use per passenger km, then David MacKay's book "Without Hot Air" has a rather good chart. Pulling from that the methods by which one might plausibly cross the atlantic (figures are approximate, as I'm reading them off the vertical scale): A Boeing 747: 52 kWh per 100 ...


12

Not sustainable at all because they use helium for lift. Currently we can't manufacture helium in meaningful quantities, so the helium we get comes from fossil fuel extraction "natural gas" as it comes out of the ground contains all sorts of gases including helium. The US government has long funded some gas extraction/purification plants collect and purify ...


11

While this doesn't fully answer the question in terms of ecological impact, David MacKay provides a good chart of the energy use of various modes of transport, here. I'll extract some figures from it (they're approximate, from me reading off the vertical axis). They refer to typical occupancy unless otherwise stated. Note that, as pointed out by a ...


11

It's hard to assume how much ecological footprint does one extra passenger add to a freighter. I'd guess it's near zero, since it's a cargo ship which needs some basic facilities for the crew anyway, so one person doesn't mean a difference. The twelve passengers limit for cruisers without a doctor means freighter travel isn't likely to be mass used, but for ...


11

Driving Strategies I did some research and personal experimentation on the topic, and here are some findings (more information in attached links). To achieve better mileage I would advocate the appropriate driving. The term defensive driving relates to proactive risk management of on-road hazards, and can be done regardless of speed and acceleration. ...


10

It depends on your definition of sustainable. Your question doesn't have an absolute answer as stated. Sustainable can refer to an individual, a community, a region, a country, or civilization as a whole. It is also used to make reference to the effect on the environment (which can become very controversial). If you make your money from the local community ...


9

From the first search I tried the first result says: According to the Second IMO GHG Study 2009, which is the most comprehensive and authoritative assessment of the level of GHG emitted by ships, international shipping was estimated to have emitted 870 million tonnes, or about 2.7% of the global man-made emissions of CO2 in 2007. Exhaust gases are the ...


8

Air is much more energy intensive. Gucwa and Schaefer looked at the impact of scale on energy intensity in freight transportation, and the chart below is taken from that paper. They looked at varying loads, across four modes - the line in the lower left is trucks, the cluster above it is air, the long spread-out light grey dots in the bottom-right is ships, ...


7

I think that you can assume, worst case, that your car will be no worse than the 10-15 seconds break-even given in the linked answer. Since your car is engineered for start-stop, if there are easy improvements to be made to minimize the cost of restarting then the manufacturer may have made them, but in any case it should be no worse than average. The ...


7

The existing answer is excellent but before you do any of that, measure your fuel usage. If you don't measure what you're doing, you don't know if you're even making an improvement. Some cars have a fuel efficiency gauge on the dash but I don't recommend watching this as you drive. The times at which the greatest gains can be made (i.e. accelerating) are ...


7

Each has pros and cons. Trolleybuses require less infrastructure (no steel tracks), and don't need the road dug up. Light rail typically (with few exceptions - Curitiba being the notable counter-example) offers much higher capacity for a given land-take: it requires a narrower corridor and it carries more people per metre lane width per minute; and has ...


7

To encourage people to not use of purchase cars develop a public transportation system that is easily accessible by the to public and caters to the needs of the public so that people will use it. Additionally, the energy source for the public transport system must be electricity. Anything that is combustible, even bio fuels, will maintain a certain level of ...


6

One of the core practices most hypermilers use that hasn't been mentioned yet is DWB - Driving Without Brakes. At least with accelerating, you are increasing your kinetic energy so can use it. Every time you hit the brakes you dissipate energy as heat and cannot recover it (unless you have a kinetic energy recovery system...) From hypermiler.co.uk (and ...


6

I have been using this method for years, on both my Toyota and my Ford Explorer. I save lots of gas, nothing has ever happened to my batteries, and have never had a mechanical problem. You need to use common sense. I typically shut it off when it's a long light and I'm in a long line, railroad crossings, and any other situation where it's going to be at ...


6

Yes, there are such databases. These are Lifecycle Cost Assessment (LCA) databases. They are very difficult and expensive to build, and expensive to maintain. And they exist. You'll need to do a web search for LCA database and your region, but they are out there. The EU has several, for different purposes. Here's the LCA database from the EU Joint Research ...


6

Looking through some of your sources and thinking about the problem, it sounds like there isn't necessarily a definite answer, but a set of tradeoffs. NOx is associated with smog and acidification, particulates are related to respiratory health, and fuel efficiency is related to global warming (among other things like cost). This problem would seem to be ...


6

According to this answer over on mechanics.SE, below a certain engine RPM, your vehicle automatically disengages the torque converter. That is to say, when stopped, there isn't a fundamental difference between having the transmission in drive or neutral. On the other hand, shifting back and forth each time you're at a stop light does cause a bit of wear, ...


6

I am not able to find any studies comparing the energy consumption. But if we look at a paper investigating emissions directly, which one could argue is an even better proxy for sustainability than energy, it seems that although the emissions from construction for railways is more than twice as large as that from the construction of airports, on a passenger-...


5

Ignoring the aspect of how effective a person works at home compared to their working place your question essentially boils down to: Are the conditions at my working place (basically all facilities you use there; including work and non work related actions) plus the transport to get there more environmentally harmful than the conditions at home? There are ...


5

Unfortunately--and I realize this is not very helpful--the best choice in terms of carbon footprint is almost certainly not to go. It's a good point that freighters are likely to be much more efficient per passenger than cruise ships, but when comparing them to airplanes, you have to keep in mind what's being brought along to accommodate the passenger, not ...


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