Abstract
This
lesson uses an econometric model as a tool for the REDD inititive which
compensates developing countries for carbon sequestration. The model accounts
for socioeconomic factors, using a spatial lag regression and a set of given
parameters. A basic scenario of business as usual and a new, dramatic scenario
are tested against each other in the model. The first model simulates the deforestation
based on the econometrics for 2001-2020. The second model provides a carbon
bookkeeping account of CO2 emmissions and deforested hectares, leading to
conclusions for stakeholders in the region.
Introduction/Background
An
econometric model is a a tool used to determine future aspects of the economy.
It uses past relationships between parameters to statistically simulate the
future, changing variables to create a variety of results. An econometric model can be useful to
simulate deforestation because socioeconomic factors on a local, regional, and
international scale heavily influence the rate of deforestation. Some benefits
of this type of modeling is that it takes into account a more compex,
anthropogenic system. Economics cannot be ignored in environmental modeling,
therefore econometric models can incorporate a more diverse aray of parameters.
Some challenges are that it requires a lot more data collection, more
statistical and mathematical effort, and a specific understanding of how local
economics influence the environment.
REDD
is an initiative on Reducing Emissions from Deforestation and forest
Degradation in developing countries. The program was developed to provide
incentives to developing countries to stop deforestation. If countries could
reduce their deforestation to below a historical baseline they would be
eligible for financial compensation from the international community,
specifically from carbon credits. Modeling REDD projects would require an
econometric model because as a country initiates policies to reduce
deforestation, they are then making money that is going into projects that do
not degrade the land. This is a relationship between economics and environment
that requires complex, multi-level datasets.
A spatial lag is when
neighboring cells affect one another in the model, due to the influence on one
variable to the other. Deforestation results in more crop areas and denser
cattle herds, while precent of protected areas decreases deforestation.
Deforestation creates more roads and increases migration rates. The latter two
may have a feedback loop that will continue to increase. To summarize,
increasing protected areas will
decrease deforestation, while growth in the other variables results from and
continues due to deforestation.
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Figure 1- Simulation Model |
The spatial neighborhood
matrix incorporates the influence of the socioeconomic context of neighboring
municipalities in the prediction of deforestation rates of a certain
municipality. This means that the matrix is designed for each municipality to
respond to the changing socioeconomic patterns around them. No municipality
works in isolation, instead they react to one another. Deforestation will not
occur within a single municipality; however it is most likely to create a
spreading pattern between municipalities. The model will run for 20 iterations
to represent 2001-2020.
Results
The
final landscape has a slight increase in deforestation (light green) that fills
in a lot of the patches from 2001. There is not a huge difference, but there is
a bit of land use change occuring around the edges of where it was already
occuring. It shows there is pressure to protect the land, and pressure to
develop the land. The municipalities develop and deforest slowly, one affecting
the other resulting in a spreading pattern, like a river delta. Intermediate
years did not help show much of a trend because 2010 decreased deforestation
and then after that it increased again.
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Figure 2- 2001 Land use map (left), 2020 Land use map (right) |
The
scenario I created was “0” growth in crop expansion and “1” or 100% growth in
cattle expansion. This was so dramatic so that I could see the result of such a
drastic change; however it was too much and made it difficult to observe the
results. The new scenario results in a lot of cattle land in every
municipality. Deforestation is vast and unruley. This is unrealistic, but
demonstrates the potential for unlimited cattle expansion.
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Figure 3- Land use map for scenario of 100% cattle expansion, 2001 map (left), 2020 map (right) |
In the carbon bookkeeping
model, the model uses 85% for the biomass emmission factor and 50% for the
Biomass-Carbon conversion factor. This
model results in excel tables that display deforestation in hectares and CO2
emissions for each year.
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Figure 4- CO2 (top), Deforestation (bottom) |
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I repeated it for scenario 2. It is clear in both
examples that the CO2 emissions mirror the deforestation to some extent.
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Figure 5- CO2 (top), Deforestation (bottom) |
They
follow a similar rise and fall pattern, although the CO2 emissions continue to
rise after deforestation ends due to a lag in the ecosystem processes. Because
of the dramatic choices I made for scenario 2, the model stops at 2004. The
deforestation declines and then stops because there is nothing left to
deforest; meanwhile the CO2 emissions increase to a massive number of more then
nine million tons. I recommend stakeholders do NOT expand at a rate of 100% for
cattle or for crops. This will result in complete degradation of the land.