Cargo ships also burn a lot of very nasty bunker fuel. The ships going through the panama canal have carbon emissions per year that rival those of all motored vehicles in the US combined (800 metric tons vs 1100 metric tons). Each ship burns 200 to 400 tonnes of fuel per day (worth $40K-$80K)
Cargo ships are also the most carbon efficient means of transporting goods. Better than trucks, trains, and planes.
I just find it funny how politicians in my country try to save carbon emissions by enforcing a speed limit on highways or only let newer cars into the city areas...it just doesnt make no difference at all on a global scale.
The fact that transporting things by sea is ORDERS OF MAGNITUDE more efficient means that it is the last thing to improve-replace.
"I just find it funny how politicians in my country try to save carbon emissions by enforcing a speed limit on highways or only let newer cars into the city areas...it just doesnt make no difference at all on a global scale."
Politicians use to be ignorant of science. Having said that, cars and trucks are the biggest polluter in the world.
I couldn't care less about "carbon emissions", but combustion particles, specially diesel from big truck, are really nasty for the environment.
Only due to their scale, there seem to be very little 'carbon reducing' technologies employed in the shipping trade.
I don't know why some sort of modern Sail power hasn't been looked at. If you're sailing with the wind why would you not save "$40 - $80k" a day?
Of wind turbines for that matter, as far as I know, most ships still derive electricity from diesel generators. Why not wind or solar?
The size of the sails / solar / wind turbine to replace this would be...? You get the idea.
As for carbon reduction, the engines already run at ~50% efficiency so there is little waste. The amount of carbon produced is the reality of pushing such a huge weight through the water.
I should have made it clearer in my post but I wasn't suggesting replacing diesel engines with Sail power, just augmenting it in the same manner as the SkySails (see response from jk4930 and markdown).
I also don't see why covering the deck in solar panels, or installing some form of wind turbine, wouldn't go some way to reducing the demand from diesel power generators.
In either case, I don't think you understand just how brutal the maritime environment is. A typical oceangoing ship has steel panels at main deck level dented in from the impact of the sea. I don't think solar panels are going to hold up so well.
Unless you can find a way for that wind turbine to both generate electricity and work as a "sail" so it propels the ship, it is just going to add drag that is counterproductive to the problem you're trying to solve.
Oceangoing cargo ships maintain speeds of up to about 25 knots. In recent years, many have practiced "slow steaming", cutting their speed in half to save 30% of their fuel needs (and doubling transit times).
By contrast, sailing ships averaged around 8 knots -- though one of the characteristics of sail is that your speed is much less predictable (and hence, shipping schedules). The ships were also much smaller than today's freighters, for various reasons. While it's possible that we could build larger sail-powered or hybrid ships today, they'd probably still be much smaller than fossil-fuel driven ships. Other alternatives include biofuels (most likely pelletized wood and/or cellulose).
I wrote about this a few months back on G+: Is solar-powered ocean freight in your future? Wait for it .... https://plus.google.com/104092656004159577193/posts/eRygnNMp...
Not true. Take a look at what Maersk does: http://www.maersk.com/sustainability/environmentclimate/page...
A lot of cargo companies have been running the ships at half speed to conserve fuel. With margins so slim and some cargos not on a tight schedule, it works fairly well. This also reduces emissions.
The US motor vehicle fleet consumed 174,930 million gallons of fuel in 2006 according to http://www.infoplease.com/ipa/A0004727.html
There are 308 gallons of fuel to the ton, in crude oil (somewhat different from gasoline, but not sufficiently different to care about)
That's 567 million tons of fuel consumed by the US motor vehicle fleet per year.
There are 370 million tons of bunker fuel consumed by the entire global shipping industry per year according to http://www.futuresmag.com/2012/10/15/cleartrade-exchange-to-...
Only a tiny fraction of that industry is presently passing through the Panama Canal.
Headlines: "Global Merchant Shipping Tonnage to Reach 12.4 Billion Metric Tons by 2015, According to New Report by Global Industry Analysts, Inc. "
"...canal traffic in 2009 reached 299.1 million tons of shipping."
The canal is much, much shorter than an average oceanic merchant shipping route, so an even lower fraction of ton-miles is spent on shipping through the canal. Transit times are on the order of 1 day (compare with a typical trip on a vessel slow steaming at 18 knots), so even if you assume they're running their engines full-blast inside the canal (they're not), this is still a tiny fraction of the above sum.
Carbon emissions, in case you weren't paying attention in chemistry class, are normally about 85% of the mass of complex hydrocarbons (nC=12n, n2H=2n, +2H=2), so these quantities are almost directly comparable. Bunker fuel is indeed nasty stuff, but their carbon emissions are not particularly unique (nor are any hydrocarbon fuel's) - they do have more subtle sulfur and particulate air pollution.
US carbon emissions from 2008 for Motor Gasoline: 1.135 BMT[1]
Total worldwide shipping emissions: 1.12 BMT [2]
And yes, its some nasty stuff they burn [3]
[1] http://www.eia.gov/oiaf/1605/ggrpt/carbon.html#transportatio... [2]http://www.theguardian.com/environment/2008/feb/13/climatech... [3]http://www.dailymail.co.uk/sciencetech/article-1229857/How-1...
Carbon is easier here because it's a lot closer to 'tons of fuel burned'.
2) Aside from that, 'motor gasoline' does not count diesel fuel, which contributes to motor vehicle emissions through our well-developed trucking industry.
3) In re: [3], they're speaking of some very specific types of pollution. Pollution we systematically eliminated in automobiles decades ago and in trucks recently by improving the refinery process & selecting cleaner oil deposits to produce low-sulfur fuel, implementing catalytic converters and combustion feedback sensors, and just generally getting smart about how we burn things. Low-hanging fruit. We could have fixed this in bunker fuel if we'd wanted to by now.
"Carbon pollution" is not like the other types of pollution. It's not a health issue, and it's not at all avoidable if you're using fossil fuels. If thermal efficiency is already up there, there is no reasonable way to reduce it in any sense, other than 'burning less'. It is also basically the same amount of carbon emissions per thermal output from coal to bunker fuel to gasoline (with slight improvements for natural gas). There's no 'cleaning things up'.
4) So... What on Earth were your original numbers supposed to indicate? Where did they come from?