thousand metric tons

[Hayden]

As a layman trying to understand quantities of CO2 emissions, I am trying to relate "thousand metric tons" to something familiar.
Should I be considering a cubic area of some dimension, a combined area and weight?
In 2003 the world total of CO2 was estimated at 5,136,928 thousand metric tons. Can that be compared to the surface area of a small town, a city, a state?
The world population is estimated at 6.5 billion, if the above total were converted to cigarettes, how many cigarettes would each person consume?
If anyone has suggestions for other comparisons for thousand metric tons, I would be grateful.
Thanks

[Guest]

A metric ton is a unit of weight. The volume occupied by a given weight of a gas depends on temperature and pressure. You'd have to use the ideal gas law, but atmospheric temperature and pressure vary, so I think it is pointless.

One metric ton = 1000 kilograms or about 2204.6 pounds, vs a US (short) ton of 2000 pounds.

You might want to search for the total weight of the atmosphere, and compare the accumulated CO2, but it is around 380 ppm or 0.038% CO2. ALso plants use CO2 in photosynthesis to grow more plant, so you really need to consider how much the biosphere removes in plant growth, too. But CO2 concentration is increasing, so total emissions exceed total takeup by plants.

[Guest]

In 2003 the world total of CO2 was estimated at 5,136,928 thousand metric tons.

Lets use proper scientific notation and recognize you don't ESTIMATE to 7 significant figures. That's 5.14 x 10^6 thousand metric tons, or 5.14 x 10^9 metric tons or 5.14 x 10^12 kg of CO2. Per a Wikipedia article, the weight of the earth's atmosphere (less water vapor) is 5.1352 (plus or minus 0.0013) x 10^18 kg, so this is barely 1 part per million per year. I actually thought it was supposed to be more like emissions 6 ppm less offsets/takeups of 3 ppm, for a net increase of about 3 ppm per year.

[Hayden]

Dear GUEST,
I appreciate your willingness to even answer the question.
The figure I quoted for metric tons was from EarthTrends.com

The direction I need to take this topic is how can these numbers be made relevant to say a 10 year old. It needs to be Pollution for Dummies.
I like the idea of working from the estimated total weight of the atmosphere.
Could 1 metric ton be compared to the weight of a SUV? And then consider 5 million units in a line to stretch so many miles?
Hayden

[Guest]

I think you need a different word than "pollution" which is reserved for emissions which are a direct threat to health (ie, poisonous).

The allowable industrial CO2 exposure per OSHA is 4% or 40,000 ppm. We are less than 1/100 of that. CO2 is vital to plants. If there were none in the atmosphere, all plant life would die. The main reason OSHA has a CO2 limit is that it is pumped into greenhouses to speed up plant growth

So the question is what is the "right" amount to balance the needs of plants, which want more, and animals, which have upper limits, as well as the climate, which may be impacted by greenhouse gas (and should the earth be warmer or cooler to please everybody). It is too complex to reduce to "pollution for dummies."

As for vehicles, 1 metric ton would be an extremely light weight vehicle, most are closer to 2-3 metric tons.

[Guest]

We in the citizenry DO need metrics to be able to understand, press for action, and know if we are making progress. The access that monied interests unwilling to change have to media is going to lead to an avalanche of claims on progress in 2008--none of which we are going to be able to evaluate for authenticity. I sometimes wonder if scientists are in love with their own versions of complexity, and if this contributes to the delay in action on behalf of the common good. I am not asking that the topic be stupified but clarified. We need common terms, common context, to act for the common good. Can the need for simplification be taken seriously? The public is persuaded. We want to put our weight behind the problem.

[MRL80]

maybe this webpage might help it has a page directed for kids.

ww.eia.doe.gov
hope it helps