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In one year, a single tree can absorb as much carbon as is produced by a car driven 26, 000 miles

I actually thought it was more trees than that.

Given current concerns with global warming, what are the members thoughts on this fact?

It may or not be 'true' but that factoid is certainly a little misleading - you can't arrange that the tree you plant will suck up all the extra carbon you produce by doing a lot of driving and it won't take into account all the other side effects of motoring culture either.

However, I'm sure it wouldn't hurt to have a lot more trees growing round the place and might well do something to soak up high CO2 levels, even if we still also have to change other aspects of how we live.

Wulf

I don't know anything about science but I have just planted my very first tree, a Liquidambar.

I've been doing a bit of surfing:

The process whereby trees absord CO2 is part of the process of photosynthesis. After absorbing the carbon dioxide, they hold onto and use the carbon part of it, and release the oxygen part back into the atmosphere.

This explains why, in prehistoric times, when CO2 levels were higher than they are today, terrestrial vegetation was prolific enough, along with low forms of marine animals, to result in huge stores of 'fossil fuels'. The result of all that carbon absorption was a reduced level of atmospheric CO2, an increased level of oxygen, and large stores of locked up carbon. The altered levels of atmospheric carbon dioxide and oxygen made it more suitable for life forms such as ourselves to prosper.

But by burning all that fossil fuel, now in the form of oil, gas and coal, we are putting back into the atmoshere all the carbon that was removed from it aeons ago. Not only that, but we are doing it in a much shorter time than it took to remove it - fossile fuel burning has really only been going on for a couple of hundred years. It probably took hundreds of thousands of years to remove it, so we stand to face a serious imbalance in any natural carbon cycle.

Figures for the amount of carbon a tree can absorb seem quite hard to find on the web, and I suspect it's the sort of thing where figures are bandied about to suit the argument being put forward.

For example, a single tree (type unspecified) can absorb 13 pounds of CO2 a year, or it can absord 50 lbs a year - take your pick. It also seems there are several other factors to consider. A fast growing tree will absorb more CO2 per year than a slow growing one, but will usually have a shorter lifespan. A young tree will absorb more than a mature tree. The process of planting trees can cause the soil to release its stored CO2 (though this will only be a short term effect). The carbon that a tree stores (apparently about 20% of its living weight) will be released again if the tree is cut down and burnt or dies and decays (although the process of decay would seem to be a whole other carbon cycle, because other plants and animals will be taking on some of the carbon that is being lost by the dead tree).

The amount of carbon a car emits is a bit easier to find, because in the UK cars are now taxed according to CO2 emissions. For example, a basic Ford Mondeo is rated at 186 grams of CO2 per kilometer. Doing some arithmetic (and converting it into units I understand), it seems that this car would emit 17,158 pounds (over 7½ tons) of CO2 in 26,000 miles. A tree absorbing CO2 at the higher rate that I found (50 lbs a year), would only be good for 75 miles a year - so around 350 trees needed for that annual mileage.

Another site suggests that a forest can absorb carbon dioxide at a rate of 22 tons per hectare (about 9 tons per acre) per year, which means that a little less than an acre would be able to deal with the 26,000 miles. If this equates with the above example, it means trees planted at a density of one every ten feet, which is probably possible in a dense conifer plantation.

Extrapolating further, an average driver, doing an average of 10,000 miles a year, will account for a third of an acre, or 135 trees. There are about 28 million cars in Britain, so this will need over 9 million acres of densly planted trees - about one sixth of the land mass.

Of course, if a tree only absorbs 13 lbs of CO2 a year, then multiply all this by 4.

And if I plant fruit trees in my garden, thereby reducing the need to drive shopping and buy fruit that has been transported by some kind of vehicle to the shop, I'll "absorb" even more CO2!

Mandy, what's a Liquidambar?

Ina

Stew, that 'bit of surfing' gives you an A level in Environmental Studies!!!

I think you must be right if the figures really differ that much - pick an amount to suit your argument! It all smacks of finding ways that we can drive loads and not feel guilty.

I suppose the point is that any tree planted will eventually die and give up it's carbon, the fossil fuels we are burning are releasing carbon dioxide into our system that has been locked up for millions of years and it is difficult to predict what that will do to our atmosphere and the living things depending on it (us).

To confound things further, based on the amount of fossil fuels burnt, the co2 levels are not going up as fast as would be expected, there seems to be some form of sink that is absorbing around half of the carbon released. Many calculations made by scientists assume that this will continue but there is evidence that the effect is starting to wane - so who knows what will happen, but it probably won't be good!

Nev

Nev, a few weeks ago new research was published here showing that CO2 was released at a much faster rate than had been thought - so I think whatever you want to prove, you find a scientist with the right kind of paper! Who ever said that science was exact!?

Ina

Ina, a Liquidambar is a tree which has pretty red colours in autumn. That's why I bought it because my outlook is too green! I love interesting autumn colours.

Extrapolating further, an average driver, doing an average of 10,000 miles a year, will account for a third of an acre, or 135 trees. There are about 28 million cars in Britain, so this will need over 9 million acres of densly planted trees - about one sixth of the land mass.

Does anyone know the area of the actual forest cover in UK? I'll do a google on it, but in the meantime....

My Googling suggests a figure of around 10 - 12% for the whole UK.

Millymollymandy wrote:Ina, a Liquidambar is a tree which has pretty red colours in autumn. That's why I bought it because my outlook is too green! I love interesting autumn colours.

That really looks very pretty, Mandy! And those prickly things are the fruits, I suppose? Spray them golden and you can start a sideline in Christmas decorations...

The total woodland in the UK is about 11.5% (Forestry facts and figures 2005, Forestry Commission); in Scotland around 17%, so England would be quite a bit less... Seeing that the population density and, I suppose, the CO2 emission is less up here, could it be that we have better air quality? At least with the current north winds everything will be blown down south, too!

Does anybody know how far from the point of emission the absorption still "works" effectively?

Ina

ina wrote:

Millymollymandy wrote:Ina, a Liquidambar is a tree which has pretty red colours in autumn. That's why I bought it because my outlook is too green! I love interesting autumn colours.

That really looks very pretty, Mandy! And those prickly things are the fruits, I suppose? Spray them golden and you can start a sideline in Christmas decorations...

Ina

Sounds like a good idea, though it may be a year or ten before I start getting any of them!

So there is justification then for acting and doing something. (Obviously)

In the new year, I am going to start developing and promoting an environmental campaign, because, through my business of Emagazines, I want to focus on the necessity to live a bit greener, keep it green and read your news on the screen, as well as reminding vehicle users that trees need to be planted. I am even prepared to donate a % of my profits into tree planting projects. I can do this both in UK and in Malawi.

I am very grateful for all the information above from you all and if any of you would like to contribute further, especially in the campaign I mention above, please contact me at mail@fridayteam.com

As I have always thought, (and in the past have done) more trees in the ground is only a good thing. (As long as they are the right trees and have a benefit to the community other than firewood. This last comment - relative in particular to Malawi)

Just found this handy calculator at:

http://www.carbonneutral.com

It says a flight to Malawi emits 2.5 tonnes of carbon and I need to plant 4 trees to balance it.