Net-Zero-Attic Carbon Manifesto and Carbon Calculation Methodology
A word of caution about carbon calculations. We are not highly resourced or sophisticated. We are simply a team of individuals that deeply care about environmental conservation. As such we have developed our in-house scientific methodology for quantifying the CO2 captured and the carbon that will remain sequestered by our green initiatives on behalf of our customers. The carbon credits market although legal per the Kyoto Protocol, it is complex and largely unregulated. Used ethically it can be virtuous, but it is also exploited viciously. Therefore, we have sought out practical ways within our means to offset the greenhouse gas (GHG) emissions of our customers. See, combating climate change cannot be left to national governments alone; the private sector, particularly businesses have a critical role to play as well. We at Net-Zero-Attic have prioritized green initiatives that have an immediate impact on human development where it’s most needed. We decided on Uganda; and with our understanding of local culture in those communities we are confident our estimates of GHG emissions removed from the environment are plausible. As we continue to grow, we are always on the lookout for other green initiatives that are more beneficial and easier to quantify. Now that we have that out of the way, let’s get into the fun part 😊 – the numbers:
According to local sources in Uganda, it takes about 300 kg of freshly cut wood (trees) to produce a sack of charcoal, which sack of charcoal weighs about 100 kg, which sack sells for about 80,000 Ugandan shillings. The average family in Uganda, that is a family of 5, uses about 10 sacks of charcoal a year. This translates to 3000 kg of trees felled and burnt annually. So, in essence, to meet cooking needs, the average family of 5 in Uganda cuts and burns 3000 kg of trees a year.
The consensus from several evidence-based and peer reviewed sources, is that a typical 1000 kg tree removes from the atmosphere anywhere from 10 kg to 40 kg of CO2 annually. The trees analysed in these studies are several decades old. The amount of CO2 absorbed per year is determined, first by calculating the amount of CO2 absorbed over the tree’s life which is then divided by the age of the tree (more on this in a minute). Many studies put the average at about 25 kg of CO2 annually for a typical 1000 kg tree. Looked at another way, the carbon stored in a tree weighing 1000 kg, when released through combustion, it would pollute the environment with CO2 in the amount that is directly proportional to the carbon burnt (more on that in a minute thanks to molar ratios).
When we insulate your attic, we buy an eco-stove for a woman-headed household in Uganda and plant enough trees to cancel out the remainder of your GHG emissions.
We have settled on planting eucalyptus trees on your behalf. These trees grow at an astoundingly rapid rate! In 4 years, they grow to about 20 meters in height with a radius at breast height of about 10 centimetres or 0.1 meters. This is equivalent to about 0.63 cubic meters (3.14 x 0.1 x 0.1 x 20) because the trees are fairly cylindrical. This translates to 1.26 cubic meters for 2 trees. We will conservatively lower the 2 trees to 1 cubic meter in volume or 0.5 cubic meter per tree. A eucalyptus tree with 100% moisture capacity can weigh upwards of 1500 kg per cubic meter. We will very conservatively lower this to just 1000 kg per cubic meter. The more conservative we are in our calculations the more plausible our calculations are. There are some facts that don’t vary much from tree to tree (Thank goodness!):
The chemical composition of wood is one of them. Cellulose (C6H10O5) n makes up most of the cell walls of trees (where n is the number of glucose molecules in a given cellulose molecule). Cellulose is essentially a polymer of glucose (C6H12O6) molecules produced during photosynthesis.
In its simplest form, the equation for the chemical reaction of photosynthesis is:
We also know that typically 50% of a tree’s weight is water. So, for our 1000 kg of eucalyptus trees, 500 kg is water and 500 kg is dry mass of wood. We also know that of the dry mass of wood, 47.5% is carbon. Therefore for 1000 kg of tree 47.5% (1000 kg) = 237.5 kg of carbon.
The molar mass of CO2 is 44; that of carbon is 12 and that of oxygen is 16. Therefore, it takes (44/12) = 3.67 kg of CO2 to create 1 kg of carbon.
Therefore, for our 1000 kg of eucalyptus (237.5 x 3.67) = 871.63 kg of CO2 is absorbed.
As alluded to earlier, if we want to know how much a 1000 kg tree absorbed per year, we need to know the age. This is even as we keep in mind that in their youth, generally trees absorb CO2 quite quickly for their rapid growth but also in their old age, their density is much greater so they can absorb quite great amounts of CO2 then too. It is still debatable for the scientific community as to when trees absorb CO2 the most, as shown in this study. Hence any rates of CO2 absorption are simply an average. One study had their trees achieving 1000 kg a tree in 35 years putting the absorption rate at 24.9 kg of CO2 per tree per year.
Our trees reach at least 500 kg a tree in 4 years. That is 1000 kg of tree weight for 2 trees in 4 years. So, using the same conclusion as the consensus, our 500 kg tree absorbs (871.63/8) = 109 kg of CO2 per year. Take for instance a client still putting out 7.7 tonnes of GHG emissions as shown by their EnerGuide label from the report provided by their Registered Energy Advisor after attic insulation, we would plant (7.7/0.109) 71 trees for such a client, to get them to net-zero for their home.
Let’s now look at what the eco-stove does in terms of environmental conservation. The wood burnt for firewood or charcoal in Uganda comes from various sources. Therefore, we can only base our estimates on the consensus of 25 kg of CO2 per year as the amount removed from the environment through photosynthesis per 1000 kg of trees (and as a simple matter of fact, at this rate, these trees would be about 35 years old). So, for our average family of 5 that receives the eco-stove, which eliminates the need to cut down 3000 kg of trees, that is just 75 kg of CO2 removed from the environment per year by the saved 3000 kg of trees. This amount is so negligible we will not even count it towards offsetting the typical remainder of GHG emissions of our customers even after they significantly lower their GHG emissions after our attic insulation.
However, what the eco-stove is very effective with in terms of environmental conservation, is the prevention of further GHG emissions into the atmosphere. From our calculations above, that is about (3 x 871.63) = 2.6 tonnes of CO2 or just under 3 tonnes of CO2 that the eco-stove prevents from being released into the atmosphere annually by an average family of 5. This amount of GHG emissions would have inevitably been released every year in producing 10 sacks of charcoal. In terms of environmental conservation therefore, we donate eco-stoves to prevent further damage to the environment.
Notice, from the simplified combustion chemical equation above, 6 moles of carbon atoms (for every repeating glucose unit) in 1 mole of a cellulose molecule yield 6 moles of carbon dioxide molecules. It is a 1:1 ratio. That is, carbon is stored as cellulose in trees but through combustion it reacts with oxygen and is released as carbon dioxide, a potent greenhouse gas, in a 1:1 ratio. You prevent this in Uganda, by your conscious buying decision for your attic insulation.
We then plant enough trees to cancel out the GHG emissions our customers are still putting out in Canada even after lowering their emissions with attic insulation.
To eliminate the remainder of your GHG emissions in Canada after attic insulation, we plant enough trees in Uganda in collaboration with the recipient of the eco-stove. We give them eucalyptus seedlings to plant, and we agree with them not cut down the trees. Culturally, Ugandans are honorable. Once they know the trees were donated, and they received an incredibly generous gift of the clean cooking stove, they will honor the agreement not to cut the trees. This is how we get to net-zero in Canada by 2050, not only by making energy saving home improvements but also by engaging other green initiatives elsewhere on the planet, because earth is our shared home.