PLANT-IT 2020'S
CARBON SEQUESTRATION PROGRAM:
Background
'Global warming refers to the increase in the average temperature of the Earth's near-surface air and oceans in recent decades and its projected continuation. The Intergovernmental Panel on Climate Change (IPCC) concludes, "most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations"
1 via the greenhouse effect. Anthropogenic effects, processes, objects, or materials are those that are derived from human activities, as opposed to those occurring in natural environments without human influences. A scientific consensus holds that man-made carbon dioxide is the primary factor driving climate change
1'. This means such activities as flying, driving, eating red meat, non-sustainable forestry practices and pretty much anything that burns gasoline adds harmful carbon compounds into the atmosphere.
Solutions
Either one can slow the rate of increase of greenhouse gasses and/or one can actually focus on reducing the total amount. Slowing the increase means flying less, driving less, carpooling, eating less red meat, purchasing products produced locally, buying energy efficient compact fluorescent bulbs, lowering the thermostat and purchasing renewable power. Reducing greenhouse gasses means planting trees in a certain way. There is experimentation with adding iron particles to the oceans but this approach is not yet scientifically proven to work.
TREE-PLANTING PROGRAMS FOR CARBON SEQUESTRATION
Some companies have taken the approach towards funding reforestation as a way of 'going green' by offsetting the carbon they use. The major question businesses have is: 'What type of reforestation program maximizes carbon sequestration and overall positive publicity while minimizing potential negative backlash and cost?'
First, companies need to know that it is impossible to generically link the planting of a tree to 'x' amount of carbon sequestration. As of June, 2007, forestry science studies in carbon sequestration related to trees simply indicate the following:
- According to the US Forest Service, large diameter, long-lived, leafy trees tend to be the most beneficial in regards to carbon sequestration. This is why Atlanta's 9 million-plus (predominantly mature, broad-leafed) trees soak-up 46,345 tons of carbon each year but Calgary, Canada's nearly 12 million trees (many conifers) only sequester 21,422 tons per year 2.
- Tree species is a strong determining factor regarding
carbon sequestration. Trees vary between being fast
or slow in storing carbon... and tree species also
vary in how much they output harmful volatile organic
compounds (VOC's) such as isoprene, which produces
the greenhouse gas ozone. Therefore, one needs to
select a tree species that rapidly sequesters carbon
but which also does not have a high output of VOC's.
In the United States, American basswood, dogwood,
Eastern white pine, Eastern red cedar, gray birch,
red maple and river birch are some of the tree species
with these characteristics.
- One study indicates that generally speaking, trees planted closer to the equator sequester more carbon than those planted far to the North. It is unclear if this is because the more Southern tree species are more likely to be large diameter, long-lived, leafy trees or for other reasons.
- In another study in Hawaii, it was found that when eucalyptus was interspersed with the mimosa, it performed better at absorbing carbon. This appears to be because the mimosa added nitrogen to the soil. Thus, 'mixing' trees in some cases may increase carbon sequestration amounts as would simply planting trees in nitrogen-rich soil as it makes trees grow faster and thus more effective at storing carbon.
- Research indicates that trees growing in sunlight as opposed to shade have greater emissions of VOC's.
- The use of power tools and vehicles in maintaining certain trees increases carbon dioxide into the air.
- Long-lived trees (those that will likely live more than 50 years) are preferred by the Forest Service for carbon sequestration as dead trees rot - releasing all of the carbon that has been stored.
WHY DO SOME GROUPS ASSIGN A CARBON OFFSET VALUE PER TREE?
There have been some isolated studies of selected tree plots where total carbon sequestration due to trees and the number of trees have been calculated - leading some to come-up with an amount-per-tree. This number however is highly misleading as the amount varies by species, age, soil quality, location, atmospheric conditions and so forth.
To come-up with an exact, scientific, carbon sequestration number, on-site research is required. For a 'scientific estimate', one needs to perform research at a nearby location with the same tree species, same soil quality and the same atmospheric conditions. Researchers would have to determine the average sequestration amount over the expected lifetime of the tree, as this waxes and wanes.
Thus, companies need to ask very hard questions of any group presenting a carbon sequestration amount related to the planting of a tree.
Plant-It 2020 uses a 'scientific estimate' with the following statistics based upon the tree species, soil conditions and tree-planting methodology we use:
600 trees in the tropics fills 1 acre leading to 15 tons of CO2 annually sequestered
40 trees = 1 ton of CO
2 sequestered each year.
1 million trees = 1,666.67 acres = 25,000 tons of CO2 sequestered annually
A SMART CARBON SEQUESTRATION STRATEGY
Trees store carbon compounds during the life of the tree but release these compounds when it dies - making trees a short-term solution. It is the soil that can permanently store carbon compounds sucked from the atmosphere via trees that can provide a much longer-term solution. Thus, you need to pick the right trees for the right soil planted in the right locations in the right way. This means sustainable forests with no timber harvest (as such reduces the soil's capability for storing carbon) in equatorial latitudes. It does not mean planting evergreens in US National Forests that get cut down for timber harvest by timber companies.
Conclusion: Trees don't perform the same way in different regions, and their ability to clean-up the air varies with age, rate of growth, and many other factors. Companies desiring to engage in carbon offset programs through tree-planting would thus accomplish their goal with the minimum possibility of criticism through sponsoring the planting of large diameter, long-lived, fast-growing, leafy trees, in nitrogen-rich soil, and in non-harvest areas where there is little or no use of power tools and other equipment used during planting and maintenance. This would occur South of the United States closer to the equator being preferable.
1 Wikipedia.org
