We each have a carbon footprint from activities such as driving, flying, heating our homes, powering all of our "devices", etc. There is also a part of our footprint we have no control of - our share of national emissions for schools, hospitals, prisons and government.
This footprint is measured in tonnes of CO₂e - carbon dioxide equivalent - though we generally just refer to CO₂. Carbon dioxide is one of the three main greenhouse gases (GHGs - the other two are methane and nitrous oxide) that form a "blanket" round the earth. Without this blanket the earth would be uninhabitable. We are making this blanket thicker by emissions from our global activities - mostly the burning of fossil fuels, but food production has a big part to play. This is causing global temperatures to rise (climate change) which is having impacts around the world (unpredictable and worsening weather, floods, droughts) which are affecting the poorest amongst us the worst.
Carbon offsetting is defined as "a compensatory measure made by an individual or company for carbon emissions..." (Collins dictionary).
In practice, offsetting is the process of acknowledging our impact on the planet and doing something about it. Money from carbon offsetting is used in developing countries to fund projects that will either remove carbon dioxide from the atmosphere (e.g. tree planting) or that will help people avoid carbon emissions (e.g. cookstoves that reduce emissions from charcoal burning for cooking).
Before offsetting, the best thing we can do is reduce our own carbon emissions. Offsetting recognises that we can never reduce our footprint to zero.
FOMAWA help and advise farms and schools on commercial tree planting – this relieves pressure and demand on indigenous forests which means they are conserved and have a chance to regenerate.
Over the last couple of years, some of the schools that joined the project at its inception have been able to harvest and sell a proportion of the trees that they have grown – bringing much needed income. Each tree is worth around 3,500 Kenyan Shillings, just under £27, and each school plants, on average, 425 trees. Wood from the trees will be sold for electricity poles and timber, the rest will be either sold in the local community as firewood or used by the school as firewood. Trees are harvested at 10 years and the coppiced stumps are allowed to regrow. Plantations can be harvested two or three times.
FOMAWA is run by Richard Muir (Chairman) and Jacob Mwanduka (Executive Officer).
For every £10 that we receive:
The money that we send to FOMAWA in Kenya is sent as unrestricted funds to be used for tree planting and growing projects at local schools. FOMAWA uses this money to pay for seedlings, fencing to protect the young trees, fertilisers and other project "consumables". Travel and staff costs are also included. FOMAWA sends CHASE Africa regular reports on progress - please contact us if you would like to know more.
The paper provides an allometric equation and coefficients that, given the diameter at breast height (DBH) for Eucalyptus (multiple species), allows for the estimation of the above- and below-ground biomass. From the biomass it is possible to calculate the amount of carbon the tree contains. Kuyah et al's paper is based on data collected in the Kakamega region of western Kenya which is climatically and agriculturally similar to the Molo/Rongai area in which FOMAWA works.
Typically, FOMAWA harvest trees at 10 years. Data from FOMAWA shows that 10 year old trees in the field (i.e. current stocks) would typically have a DBH of 25cm, with sizes ranges from 22cm to 28cm. Calculating the carbon content of any tree relies on knowing its carbon fraction – the proportion of the tree that is sequestered carbon. Kuyah et al give the carbon fraction of kiln dried Eucalyptus as 47.5% based on element analysis.
Based on molecular weight, carbon dioxide weighs 3.67 times as much as carbon. So, if you know how much carbon is in the wood, you know how much carbon dioxide has been removed from the atmosphere - the O₂ part of the CO₂ is released back into the atmosphere for us to breathe.
For 425 trees planted on an acre of land we would expect that over 10 years the trees would sequester a total of 234 tonnes of CO₂ in above- and below-ground biomass (425 × 0.551). But the story doesn't end there...
In terms of carbon sequestration potential for the sale of carbon offsets we can only consider the following:
This means that of all the carbon sequestered over those 10 years, approximately 80 tonnes of carbon dioxide will ultimately be returned to the atmosphere after harvesting from being burnt as firewood, or lost during logging. In terms of biomass – 57 tonnes of harvested timber will lock up carbon long term, a further 30.9 tonnes will remain in the ground as living roots. Firewood will account for the remaining 39.7 tonnes. The leaves (6.8 tonnes) will either be burnt or used elsewhere.
In any tree growing project there is always a risk that trees will be lost for a variety of reasons. Building a buffer into the carbon sequestration potential calculations allows for the risk of any future loses to be accounted for. The size of the buffer is somewhat subjective, but a very conservative buffer for this project would be 20% of sequestered carbon. Data from FOMAWA shows that over the last 12 years the average survival rate is 93.2% (i.e. 6.8% of the trees are lost). Taken over the last five years the survival rate is 96.4% due to improved seedling stock and procedures on the ground. Thus a 20% buffer should prove to be more than adequate. The buffer covers any of the following loses:
The list is non-exhaustive.
Allowing for a 20% buffer means that, per 425 trees planted, of the 153.4 tonnes sequestered, 30.7 tonnes will not be available to sell as offsets - leaving 122.7 tonnes available that you can buy from us.