Which produces more carbon dioxide....?

Question

....the average family compact car doing average annual mileage OR the average family (2 adults + 2 children) just breathing for a year? (We can leave digestive gases out of the equations!) I have seen a calculation showing that they produce about the same...2.5 tonnes. Is this right? (..and pretty scary when you look at the impact of global population growth, irrespective of what we do to reduce industrial emissions!) The carbon emissions of cars is easy because all new cars have it as part of their specifications...so many g/km and the 2.5 tonnes is about right. I get stuck in the bio-medical-mathematics for the breathing though! Thanks for you help.

Perhaps you guys did not quite understand my question. I wanted help on the calculation of: How much CO2 does the average family exhale in a year? I am not arguing either side of the GW question, just after facts.

I think it is more a philosophical question as to whether human breath is natural. Is 1 million or 6 billion people exhaling more or less "natural"? Humans are just a blip on the geological time scale. The only reason there is all this oxygen around is because first blue-green algae in the Cambrian then global forestation through the Carboniferous, to say nothing of the Jurrassic grasslands ALL EXCRETED IT and left it lying around for oxygen hungry and mobile animals to use!

Thanks for your lengthy replies. My actual question STILL is...how much CO2 does a human produce? I have yet to find an internet source with the straight answer to that. I cannnot believe that the calculation is beyond us all!

I fully understand the delicate balance of the CO2 cycle and what is scrubbing it from the atmosphere. What I don't understand is how the oceans and forests absorbing CO2 can tell the difference between us burning more hydrocarbons and us doubling our exhaling human populations?

As a point of interest, the TV show Myth Busters did a test on which used more fuel, driving with the window open or using the aircon. They found that the extra drag produced by spoiling the aerodynamics of the car by having the windows opened, actually used MORE fuel.

OK!...I thought I understood the problem ...but now I REALLY understand. I am (an old) graduate scientist and it has taken a while to get through to me. So I can understand why the "general population" might have a problem with the amount of contradictory "evidence" floating around in the public domain. Thanks for your patience.

Answer 1

Surprisingly, scientists have proven that it makes a big difference where the CO2 comes from. I know some people find that hard to understand, but let me try.

There is a natural "carbon cycle" that recycles CO2. But it's a delicate balance and we're messing it up.

Look at this graph.

http://scrippsco2.ucsd.edu/graphics_gallery/mauna_loa_record/mlo_record.html

The little squiggles are nature doing its' thing. CO2 falls a bit during summer when plants are active, and rises during the winter. The huge increase is us, burning fossil fuels. The scientists can actually show that the increased CO2 in the air comes from burning fossil fuels by using "isotopic ratios" to identify that CO2. The natural carbon cycle buried carbon in fossil fuels over a very long time, little bit by little bit. We dig them up and burn them, real fast. That's a problem. More here:

http://environment.newscientist.com/channel/earth/climate-change/dn11638

Man is upsetting the balance of nature. We need to fix that.

EDIT - Here's how nature knows the difference. The CO2 you exhale recently came from plants taking it out of the atmosphere, either because you ate the plants or ate animals that ate the plants. Putting that back is not a problem. It's the stuff that made fossil fuels thousands of years ago that's the problem.

Answer 2

The big difference is that the CO2 we exhale is part of the natural carbon cycle. The carbon in our breath comes from the food we eat and is then quickly absorbed again to nature by green plants when emitted. The carbon from oil and coal has been buried for millions of years. When we burn them, we therefore add on to the natural carbon cycle in a speed that nature cannot deal with.

Hope this answered your question.

EDIT:
After your additional notes: From my research it looks like humans exhale about 1 kg of CO2 a day but this is relative to the amount of carbon hydrates a person burn each day so it varies a lot in both directions. Still 2.5 ton a year seems to be a bit high for your 4 person family.
Here's a source: http://www.gcrio.org/doctorgc/index.php/drweblog/C48/

Answer 3

Imagine people think there's such a thing as "natural" and "unnatural" carbon dioxide. CO2 is a gas, not a pollutant. It is just 1/2500 of the total make up of the air we breathe. Man as added 0.001% to the total of all co2 in the air.

And when we add it to the air, plants and trees take it out. Nothing man can do whether it is to drive a car, or to breathe has any effect on the climate.

In total, neither produces any measurable difference.

Answer 4

the point we'd like to make is NOT, my dear, that CO2 emitted by a car is worse in itself than the CO2 emitted by humans... You don't seem to understand the impact of the emissions of all these cars on nature. just think about it: animals also emit CO2, just like humans do. And even though there are more humans now than than 200 yrs ago, we're still part of this natural cycle. of course it's not exactly great for the environment that our numbers are shooting up and that we breed vast quantities of farm animals, but adding the cars, (which burn oil and do NOT breathe... oil which is a product of millions of years of evolution taking place and animal excrements and - carcasses and plants turning into oil over a veery long period of time) it's really just too much for the natural balance to take. add the fact that we're killing all the big forests of the world (the "lungs" of the world, as they are often called, cause they actually clean the air), well, we're really ruining the environment.
the good news is you can do something against it:
-try using a bicycle or public transport as often as possible
-try to take the train instead of the aeroplane when going on holiday (here in europe that's usually no problem, i guess it's different in the states)
-try to save energy by shutting lights, unplugging electronic facilities instead of leaving them on standby
-dont eat fishsticks or any fish that comes from the ocean, because thanks to new methods in fishing and the use of illegal fishnets the numbers are decreasing incredibly fast and the whole ecosystem of the ocean is being ruined (because fishingnets don't only catch the fish that lands on your plate, in fact most of the fish they catch is thrown back in the ocean (by then it's dead, of course) because it's inedible (turtles, dolphins, sea birds and all sorts of inedible fish fall prey to these nets, plus corals get destroyed by certain nets that even scrape the ocean floor "clean")
you can eat fish from organic farms, though
-try to eat organic food as often as your budget allows you to . i know it's expensive, but organic farms are much less of a burden on the environment
-you can even buy organic make-up (which is just as good and often easier on the skin than the common version) brands such as Aveda, Logona or Dr.Hauschka are great quality
-when going on holiday, try to give ecolodges or other environmentally conscious places preference
-when in your car (if you can't avoid using one) open your window whilst driving instead of using the air-conditioning as often as possible
-also when you're stuck in a traffic jam, remember to switch off your motor.


there's really lots you can do to help build a safe environment for the coming generations!
and if it seems like a big effort, remember we only have this one world... many species have already been made extinct by man- let's not let it get worse!
Greenpeace or WWF (world wide fund for nature) offer more information, if you'd like to know more!
good luck!

Answer 5

Stop smoking cigarettes, stop using car which using gas Fueln n Coral Train, why don;t we use horse once more like in wild wild west :)

Answer 6

C+02=Co2.

two molecules of oxygen with one molecule of carbon gives carbon dioxide.

More C with double o2 gives more carbon di oxide.

:)

Answer 7

"Trees cause more pollution than automobiles do" -- Ronald Reagan in 1981