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say, net photosynthesis rate of xxx trees equals to consumption of as much CO2 per some time as one car produces during the same time, ok?.

if you could please do the calculation and give me also the data, the figures u used in the calculation- i am asking this question so that i can have some variation of the figures, some interval. and also so that we can all see how much CO2 is being added to the air...

thank you very much for your effort

my igures, just at random - CO2 emission of a car 120g/km, net fotosynthesis production of a temperate forest - 300kg dry matter per year, so it is around or above 200hectars of forest for one car.

2006-07-25 01:17:56 · 4 answers · asked by iva 4 in Environment

to campbel - dont you think that soon you will run out of place where to put the trees and the trees dont live forever but die and produce C02 as they decompose or the wood is used

2006-07-25 03:14:57 · update #1

4 answers

I can't calculate a photosynthesis rate but I can say that the end result of the process is to take carbon from the air and make it into wood. So all you need to know is how much wood needs to be grown to take up the amount of carbon you want taken up. Wood is mostly made of cellulose, which is about 44% carbon by weight. So for every kg of carbon you want to remove from the air you need to grow about 2.3 kg of cellulose. Since wood is usually wet, that is containing lots of water, I am sure that you need much more than 2.3 kg of wood to trap 1 kg of carbon. I'll just guess that you need 4 kg of wood to trap 1 kg of carbon. So you would need to know how fast a given kind of tree grows and how heavy its wood is to calculate the number of trees needed.

The important point here is that the carbon is only kept out of the air as long as the wood is preserved. If the tree dies and the wood decays, then the carbon will be released back into the air. So you may plant X number of trees to take up the carbon from your car, but unless you can guarantee that your decedents will prevent the dead wood from decaying forever in the future, then eventually, maybe hundreds or thousands of years in the future, all the carbon you though you removed from the air will be right back there. So growing trees is no favor to future generations. Better to make methanol from the wood to run your car. That way, every kg of CO2 you add to the air was first created by taking it out of the air. This solution is a favor to future generations, since it causes no net increase in CO2 in the air.

The bottom line here is, it is not how many trees you plant; it is what you do with those trees in the future. And it is not only trees. There are many kinds of plants than can be used to make methanol and ethanol fuel. For example, sugar cane is used in Brazil to make ethanol. Any fuel made from plants is taking CO2 out of the air. It is OK to put CO2 that came from the air back into the air. The bad thing to do is dig up of coal, oil and natural gas and burn it to take underground carbon and put it into the air as CO2.

2006-07-25 03:07:54 · answer #1 · answered by campbelp2002 7 · 0 0

Gasoline is almost completely hydrocarbons (give or take a little ethanol or other oxygenates). Dry wood is almost completely hydrocabrons. The C-H ratio varies a bit, but not much.

So dry wood = gasoline/diesel to within 5% or so.

My Prius uses 300 gallons = 1800 pounds of gasoline to go 15,000 miles per year. A Hummer would use more.

A board-foot of dry wood is about 2 pounds (1" x 12" x 12", density = 0.40). So 900 board feet/year of driving. 10 average sized mature trees.

From the URL below, forests are about 7000 board feet per acre. So 1/8 acre per year. 0.05 hectares. Times the number of years. More for that Hummer.

2006-07-25 05:34:28 · answer #2 · answered by David in Kenai 6 · 0 0

a million. There are a lot less timber and foliage. 1/2 the rainforests interior the international were destroyed to sparkling floor to graze farm animals to make pink meat burgers. The burning of the forests contributes 20% of all eco-friendly-homestead gases. more effective or less a million,000 species a twelve months develop into extinct by using destruction of the rainforests. 2. There are more effective carbon emissions than ever earlier by using a inhabitants improve of mankind and the upward push in animals raised for human intake. Animal waste (feces) generates double the quantity of carbon emissions than motor vehicle use.

2016-11-25 22:52:46 · answer #3 · answered by Anonymous · 0 0

the question is irrelavent. there is still co2 from the first model T floating around in our atmosphere

2006-07-31 12:09:13 · answer #4 · answered by #1Hippi 1 · 0 0

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