Math! How much can the tree or forest sequester CO2?

Yes, I am intrigued by such question: how much really a tree or forest can capture or sequester the CO2 released anthropogenically (fossil fuel and natural gas being the primary target)?

Thus, I set out to search for the calculations, and awared that a lot of people are using tree/plant for CO2 sequesteration program, like in the carbon offset bussiness. This whole bussiness thing is a complex one, and my question is relatively a simple or crude one: how much CO2 is absorbed or sequestered by tree/plant or forest in a quantitative way?

Few values or data related to this field are found. Let’s start with the number from established organization like Environmental Protection Agency, US:

Claim#1: Afforestation: 0.6 to 2.6 metric tons of C per acre per year.
             Reforestation: 0.3 – 2.1 metric tons of C per acre per year.

Next, in this report, it is claimed that:

Claim#2 (a): … 1 m3 of growth in forest biomass (stem, roots, branches, etc.) absorbs 0.26 tCe (Brown et al., 1986), … the average rate of growth is 15 m3/ha/year. And,

Claim#2 (b): This is equivalent to 815 million (m^3) bone-dry tonnes of wood, which in turn corresponds to 0.41 GtCe.

Claim#2 (c): Assuming a yield for hardwoods of 35 m3/ha/year, this would mean sequestering about 9 tCe of CO2 /ha/year.

According this paper:

Claim#3: In addition, the rate of C sequestration based on biomass change in vegetation was recorded to assess the optimum land use that can absorb the carbon dioxide emitted by the power project. These are as follows: (a) tree plantations (10.09 tC/ha/yr) >coconut (4.78 tC/ha/yr) >brushland (4.29 tC/ha/yr) > (b) natural forest (0.92 tC/ha/yr).

Ok, now it is time to make all these data comparable, if possible:

Thus, let’s say if I need to plant the tree to capture or sequester the CO2 which spewed by my car, as calculated here, with a daily mileage of 25km and emitted roughly 1104.1 kg CO2, or 301.1 kg of Carbon equivalent (1 tonne Carbon equivalent = 3.667 tonnes CO2) per year, I would need:

Claim#1 (a): Afforestation area = 0.301 ÷ 3.633 = 0.0828 ha = 828 m^2.

Claim#1 (b): Afforestation area = 0.301 ÷ 15.873 = 0.0190 ha = 190 m^2.

Claim#2 (c): Hardwood plant area = 0.301 ÷ 9.00 = 0.0334 ha = 334 m^2 .

Claim#3 (a): Tree plantation area = 0.301 ÷ 10.09 = 0.030 ha = 300 m^2.

Claim#3 (b): Natural forest area = 0.301 ÷ 0.920 = 0.327 ha = 3270 m^2.

Claim#2 (a): Biomass volume required = 0.301 ÷ 0.260 = 1.157 m^3.

Claim#2 (b): Biomass volume of bone-dry woods required = 0.301 ÷ 0.503 = 0.598 m^3.

So, an area ranging from 190 m^2 to 3270 m^2, depending on the efficiency of carbon sequesteration rate (which in turn a lot of factors are playing in) is required to absorb/capture the amount of CO2 emitted via my car. I wonder how much do I have to spend if I bought the land in Malaysia in order to do this? And if 26 millions of Malaysians need to do this, how much land area is required, per year? Hmmmm….

12 Comments

  1. Gerald Van Bommel said,

    August 13, 2007 at 5:15 pm

    You need to factor in the fact that when the tree decays it will release carbon in the form of methane which is a far worse greenhouse gas than carbon dioxide.

  2. mich said,

    August 13, 2007 at 11:58 pm

    Well, the tree will grow and live for at least few tens years, and hardwood type tree do not decay easily, so I do not factor in the release of C yet…

  3. dinesh said,

    October 12, 2008 at 11:17 pm

    Dear Sir:
    I want to know the name of the trees absorbe more Co2. I will appreciate your help. I know about the algae they do this job well

  4. Al said,

    August 10, 2009 at 2:10 pm

    I do not buy into the whole CO2 global warming thing. Yes, we need to do something to protect the planet, but Carbon Offset… Really…? How much CO2 is actually released each year? How much will a plant/tree actually absorb? How much new growth is there each year? None of these can be answered without guessing. Not to mention that the actual level of CO2 in the atmosphere so little. 380 PPM or .038%… There is to much that does not add up… G.Warming is a hoax… A fund raising, policy making scam…

  5. Sophia said,

    August 13, 2009 at 3:49 am

    Hi, its a good question. One answer is that a tree planted in the tropics absorbs 50lbs of CO2 annually. That’s according to Trees for the Future.

    Trees for the Future is planting 100 trees for every t-shirt or pair of shoes sold by this clothing brand called treeality, which I’m involved with. Treeality sponsors the planting of 100 trees for each product they sell such as Womens shoes and mens, womens and unisex t-shirts including EDUN LIVE African made, sustainable manufactured t-shirts and American Apparel organic cotton t-shirts. So 100 trees planted would absorb 5,000 lbs of CO2 annually. That’s why they’re called the greenest black t-shirts ever! http://www.zazzle.com/treeality*

  6. Sam Watkins said,

    August 25, 2010 at 8:07 am

    I wrote a small informal paper on this topic: http://sam.ai.ki/co2-and-forests.html

    My conclusion was that historical deforestation is a more significant cause of global warming compared to human CO2 emissions.

    I would greatly appreciate any review and feedback, as I am not a climate scientist and I’m am not sure that my reasoning and math is correct.

  7. Samantha Atchison said,

    August 30, 2011 at 7:22 am

    Hi there,
    I was wondering if you knew about specific trees that absorb more carbon than others. It’s for a science competition, and I can’t seem to find any specific trees than collect and store more carbon than others.

    Any advice or ideas would be much appreciated,
    Samantha

  8. sswam said,

    August 31, 2011 at 5:05 am

    @Samantha, I suppose trees that grow more quickly absorb more Carbon while growing. You could search for fast growing trees, perhaps. It would depend also on the density of Carbon within the tree. I suppose some woods have more or less Carbon, water, etc. compared to others.

  9. October 2, 2012 at 1:26 pm

    Expert and tree production and tree planting with several community in West Africa specially Ghana and Togo like contact you for more information .
    thank

  10. October 2, 2012 at 1:35 pm

    I like to continue this project to help the human for alleviate climate change damage , poverty in our country in this world and have enougth CO2 emissions .

  11. Paul Teleg said,

    August 19, 2013 at 3:16 am

    do you know any reference where I can get the volume of CO2 absorbed by different shrubs? I would appreciate a response. Thank you

  12. ismail said,

    October 6, 2015 at 10:39 am

    This site is quite educational! Pls may I know jow much co2 footprint is released by wood, kerosene, gas and charcoal burning


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