Does anyone know how much a CO2 pollution a big?

Question

I trying to figure out how much pollution a cruise ship puts out.

I heard that them ships burns a lot of diesel fuel and are a major contribution adding a lot

Carbon Dioxide (CO2) to our atmosphere.

I trying to figure out how much CO2 they could be adding to or atmosphere.

I like to compare a big boat to the cars. It would be interesting if we could learn more about

the levels of CO2 a cruise ship or big ship leaves behind and adds to or atmosphere.

If we knew how many cars where running and could compare the CO2 level to a boat running them we have a idea how much CO2 level between them and compared to each other the levels of CO2 they put out.

For instance I have no idea how much CO2 a big boat like the largest Cruise ship puts out when traveling or just running.

And I have no idea how much CO2 a car puts puts out traveling or just running.

But it be nice to know how many cars running will it take to reach or make the same levels of CO2 as a Big Cruise ship running.

Answer 1

78% more than if they ran on biodiesel.

Answer 2

According to the link below a typical large cruise ship consumes about 30 gallons of fuel per mile traveled, or to put in the terms cars used that would be about 1/30th of a mile per gallon. That compares to the average car driving in the US today which gets about 23.1 miles per gallon. There is another factor for cruise ships. They use a lot of electricity and they use on-board generators to make that electricity. According to the third link only 40% of a ship's fuel consumption goes to propulsion. Sixty percent is used to generate electricity so that will drop the mileage from 1/30 mpg to 1/75 mpg.

So a cruise ship uses about the same amount of fuel as 1,733 cars on a per mile basis. However a typical cruise ship will run about 300 miles per day which is about 10 times more than a typical car and so one cruise ship will use about as much fuel as 17,500 cars per day.

According to Wikipedia there are about 1200 cruise ships and ocean liners currently operating so means that world wide all cruise ships use about as much fuel as 21,000,000 cars. In the United States alone there are about 243,000,000 passenger vehicles so that means that all cruise ships equal about 1/10 th of all passenger vehicles in the United States. That means cruise ships area a small but significant source of CO2 world wide.

Update:

Rodney R. The emission figures you are quoting are for things other than CO2. The higher pollution figures for ship engines are for byproducts like VOC's (unburned fuel), NOx, SO2 etc. Those are the things that pollution controls on cars reduce. The amount of CO2 produced is a direct result of burning a fuel that contains carbon and is therefore strictly a function of the amount of fuel burned and therefore the figures I gave are more or less correct. The 40X factor you added is not correct.

bkc99xx: You make an excellent point, but I think your calculation assumes that each car has only one person in it. Since cruise ships are almost always used for vacationing rather than say commuting I think the more accurate comparison would be to compare a family on vacation in a single car and a family on vacation on a cruise ship. If you assume a family of even just two people the car has the fuel per person mile advantage over the cruise ship.

Answer 3

So, using the math that Engineer provided, for a large cruise ship using 75 gallons per mile, for a 7 day trip at 300 miles a day, the ship would use 157,500 gallons.

Also, for that large size ship, there would probably be 2500 passengers or more.

Therefore, at 2500, each passenger's share would be 63 gallons. Using the average gas mileage of 23.1 that Engineer did, that would be the equivalent of dring 1455 miles, not counting variations in gasoline to diesel. But, you just traveled 2100 miles on the boat versus the equivalent of 1455 by car.

Also, the fairly large portion of the gas used to create electricity is partially offset by the electricity that you would have used anyway if you stayed at home, heating and cooling your house, cooking meals, etc.

So, the actual energy usage for a week's trip per person is really not as high as you might think, due to the large number of people that the usage is spread out over. What would be bad is for ships at low occupancy rates. That would increase it a lot per person. Kind of like when certain politicans or celebrities insist on chartering private jets to carry them around.

Good luck.

BTW, each gallon of fuel burned creates approximately 20 pounds of CO2.  So, with this answer and Engineer's answer above, you can convert the usage into pounds of CO2.

ADDED:

True, Engineer.  And there are certainly many ways to look at this problem.  I looked at it from the emissions per person perspective to show that even though it would put a lot of CO2 into the air, 1 person going on a trip would not be equivalent to adding thousands of cars per year on the road.  Maybe a better way to look at this would be to calculate an average person's carbon emissions for a normal week, for a week of vacation (say 500 miles one way drive), and for a typical family of 4.  Thanks for your input.