Transcript Adaptation to CC in African Forests

Adaptation to CC in African
Forests
UNDP Accra
Forest Model
Emission Scenario
Climate Outcome
Ecosystem Model
Timber Response
Carbon Response
Economic Outcome
Ecosystem Model
• Predicts boundaries of biomes (grassland,
forest, savannah, desert)
• Predicts fire
• Predicts NPP
• Predicts carbon storage
• Predicts how all of the above factors shift
with climate change scenario
Timber Model
Volume
Age
Shape of Volume Function
• Almost all life forms are S shaped
• Implies percentage growth rate falls over
time (with age)
• Average growth rises over time to
maximum and then falls
Percentage growth
% Growth
Interest rate
Age
Economic Model of Timber
• Maximize present value of timber, W
• W=P*V(A,T)exp(-r*A)-C/(1-exp(-rA))
• Optimal age A, maximizes W, and
depends on temperature, T, and C is cost
of plantation
Climate Change Effects
• Climate change will move boundaries of
forest (suitable land)
• Climate change will alter NPP- growth of
trees
• Climate change will alter fire frequency
Adaptation
• Harvest trees early if vulnerable to
increased chance of fire or if slow growth
• Plant new tree species if will do better
during lifetime of tree
• Plant only in land suitable for trees (adapt
to changing boundaries of biome)
• More (less) intensity (fertilizer other inputs)
if more (less) productive
Suppose CC Reduces Growth
Original
% Growth
New
Interest rate
Age
Including Carbon Storage
• Carbon is captured in body and roots of
tree
• Trees take carbon out of atmosphere
• Trees help mitigate greenhouse gas
problem
• Carbon is proportional to volume
Impact of including carbon
• If farmers are given an incentive to store
carbon, they will include this incentive into
their harvest and planting decision
• Carbon payments make forests more
profitable (expand forest area) and make
longer rotation ages more profitable
Examine case study
•
•
•
•
•
•
•
Loblolly pine
Examine timber alone
Add carbon benefit
Introduce CC on timber
Introduce CC on timber plus carbon
Assume P=$.15/bdft, C=100, R=.04
Assume carbon price=$5/ton/yr