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Impacts of Climate Change in
the Tropics
Mike Jones
Botany Department
School of Natural Sciences
The greenhouse effect
“Climate Change 2007”
The IPCC 4th Assessment Report
• 2,500+ scientific reviewers
• 800+ contributing authors
• 450+ lead authors from
• 130+ countries
• 6 years work
• 4 volumes
• 1 Report
Atmospheric concentrations of important
long-lived greenhouse gases.
Source: IPCC, 2007
Changes in Mt. Kilimanjaro ice cap and snow cover over time
Source: IPCC, 2007
Record of recent warming.
Source: IPCC, 2007
Examples of regional impacts as warming occurs
Source: IPCC, 2007
Relative vulnerability of coastal deltas
Source: IPCC, 2007
IPCC conclusions
• Africa is one of the most vulnerable continents to climate
change and climate variability, a situation aggravated by
the interaction of ‘multiple stresses’, occurring at various
levels, and low adaptive capacity (high confidence).
• African farmers have developed several adaptation
options to cope with current climate variability, but such
adaptations may not be sufficient for future changes of
climate (high confidence).
IPCC conclusions
• Agricultural production and food security (including
access to food) in many African countries and regions
are likely to be severely compromised by climate change
and climate variability (high confidence).
• Climate change will aggravate the water stress currently
faced by some countries, while some countries that
currently do not experience water stress will become at
risk of water stress (very high confidence).
IPCC conclusions
• Changes in a variety of ecosystems are already being
detected, particularly in southern African ecosystems, at
a faster rate than anticipated (very high confidence).
• Climate variability and change could result in low-lying
lands being inundated, with resultant impacts on coastal
settlements (high confidence).
• Human health, already compromised by a range of
factors, could be further negatively impacted by climate
change and climate variability, e.g., malaria in southern
Africa and the East African highlands (high confidence).
Mitigation
• So far most discussion on tackling climate
change has focussed on mitigation.
• Mitigation involves limiting emissions in
order the lessen the severity of climate
change.
• Even if we reduce GHG emissions now,
some degree of climate change is
inevitable and unstoppable.
• Carbon dioxide remains in the atmosphere
for around a century.
Carbon sinks in the African jungle.
Between 1968 and 2007 African forests
stored 0.63 t C ha-1 yr-1
Global tropical average is 0.49 t C ha-1 yr-1
Two explanations:
Forests recovering from disturbance
Or
Direct effects of rising CO2
WWW.afritron.com
Reducing Emissions from Deforestation
and Forest Degredation (REDD)
• Forest removal accounts for 20% of C
emissions.
• Tropical forests account for 50% of landbased sinks.
• REDD is a UN financial programme to
reduce emissions in developing countries.
Wetland Sinks -Papyrus swamp vegetation
Eddy Covariance Equipment.
•Sonic Anemometer
•Open Pathway Infra Red
Gas Analyser
•Net Radiometer
•Quantum Sensor
•Wind Speed and Direction
•Temperature and Relative
Humidity
EC Data - Diurnal CO2 Flux in Papyrus.
30
CO2 Flux umol m-2 s -1
20
10
C Release Respiration
C Release Respiration
0
0
2
4
6
8
10
12
14
-10
-20
C Uptake
Photosynthesis
-30
-40
Hour of Day
16
18
20
22
Adaptation
• Adaptation means reducing vulnerability to
changes in the climate.
• It is the adjustment of a system to moderate the
impacts of climate change, to take advantage of
new opportunities or to cope with the
consequences.
• Poverty has an impact on adaptive capacity. It
means fewer resources to make adaptations.
• Compare the ability of the Netherlands and
Bangladesh to adapt to sea level rise.
• Tackling poverty is essential if people are to have
the capacity to adapt to climate change.