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….