Forests play an important role in regulating Earth's climate by absorbing carbon dioxide from the atmosphere and storing it. However, deforestation and forest degradation release this stored carbon back into the atmosphere. Studies show that half of the Amazon forest relies on deep root systems to remain active during seasonal droughts, releasing water vapor. Drought experiments revealed large canopy trees are most vulnerable, with lianas and trees more vulnerable than palms. Protecting forests provides ecosystem services to nearby areas, like increased crop yields, worth tens of thousands of dollars annually. Without changes, over half of the Amazon could be cleared or degraded by 2030, emitting 15-25 billion tons of carbon. A 20-year agenda could potentially reduce carbon emissions

1. Forests in the Balance: Forests as Providers
of Ecosystem Services vs. Emissions from
Deforestation and Forest Degradation
Daniel Nepstad
Chief Program Officer, Environmental Conservation Program
June 18, 2009

2. 2

3. 3

4. Forests inhale and exhale on an annual cycle 4

5. Forest carbon stocks leaking into the 5
atmosphere: deforestation
Houghton et al. 2007;
Page et al. 2003;
Alencar et al. 2006

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~half of Amazon forests depend upon deep root systems (>8 m) to
remain physiologically active during seasonal drought, supplying
the atmosphere with water vapor
Nepstad et al. 1994 Nature

8. A drought threshold experiment: 2000-2005 8
Nepstad, et al. 2007 Ecology

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The drought threshold:
•Large canopy trees are
most vulnerable to
drought
•Lianas and trees more
vulnerable than palms

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Nepstad et al. 2007

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13. Value of forests to nearby coffee farms 13
Coffee near forest (within 1 km):
• 2x more bee visits
$
• 5x more bee species
• 20% higher yields
$
Lowerbound value of forest:
• $60,000/year (7% of farm revenue)
• Equivalent to competing land uses
Ricketts et al. 2004. PNAS 13

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Forest dieback has begun

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Amazon 2030: 55% cleared or degraded; 15-25 B tons C emitted
Nepstad et al. 2008 Phil Trans Roy Soc

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Nepstad et al. 2006 Cons Biol

20. REDD alone is not enough. The world needs 20
more food
Area of Cattle & Sugar Cane, Brazil
200
180
160
140
Millions of Hectares
120
100
80
60
40
20
0
Cattle Pasture 2006 Sugar Cane 2006 Sugar Cane 2020

21. A 20-year land agenda 21
Could we reduce carbon emissions from land by 3 B tons per
year in two decades?
2.5
Carbon emissions from the land
2
3 B ton reduction by 2020
(Billions of Tons per Year)
1.5
1 Deforestation
New Forests
0.5
Soil Carbon
0 Net Flux
-0.5
-1
-1.5
2010 2020 2030 2040 2050
Year