Climate change signals in the Greater Horn of Africa and possible adaptation options
Christopher OludheDepartment of MeteorologyUniversity of Nairobi/ICPAC
THE 3RD CRAM (CROP ANDRANGELAND MONITORING) WORKSHOP IN NAIROBI, 26 - 30TH
September, 2011, RCMRD, Nairobi, Kenya.
• Climate – Is the average weather conditions (taken over a period not less than 30 years), including seasonal to inter-annual extremes and variations locally, regionally and across the globe.
• Weather is the day to day variations in the climate parameter.
• Climate variability – Is the year to year fluctuation or the variation in mean state of climate on all spatial and temporal scales.
• Climate Change refers to a change in the state of the climate that persists for an extended period, typically decades or longer. Climate change may be due to natural and anthropogenic processes.
Some Definitions
The climate of any given place is determined by the global climate system that includes the atmosphere, the hydrosphere (liquid water), the cryosphere (ice and snow), the lithosphere (rock and soil) and the biosphere (plant and animals, including humans).
The science of climate change
The Earth’s climate is influenced by the amount of energy coming from the sun, and also by other factors including amount of greenhouse gases and aerosols in the atmosphere, and the properties of the Earth’s surface, which determine how much of this solar energy is retained or reflected back to space.
Climate Change Concept: Change in mean, frequency and magnitude
CO2, NH4 and N2OConcentrations before Industrialization and Now
SOURCES OF GHG• Carbon dioxide (CO2): combustion of fossil fuels, solid waste,
wood, and wood products; cement manufacture. Human activities can also enhance or reduce removals of CO2 from the atmosphere by vegetation and soils (e.g., via reforestation or deforestation).
• Methane (NH4): coal mining, natural gas handling, trash decomposition in landfills, and digestion by livestock. Significant natural sources include wetlands and termite mounds.
• Nitrous oxide (N2O): nitrogen fertilizers, certain industrial manufacturing, and combustion of solid waste and fossil fuels.
• Chlorofluorocarbons (CFC), hydrochlorofluorocarbons (HCFC), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6): commercial, industrial, and household products.
;
Global air temperatures amomalies
Observed effects of Climate Change• Sea level is rising. • Arctic sea ice is melting• Glaciers and permafrost are melting. • Sea-surface temperatures are warming. • The temperatures of large lakes are warming. • Heavier rainfall cause flooding in many regions. • Crops are withering• Extreme drought is increasing. • Ecosystems are changing• Hurricanes have changed in frequency and strength. • More frequent heat waves. • Warmer temperatures affect human health. Seawater is
becoming more acidic
Courtesy: NASA
SOME REGIONAL INDICATORS OF CLIMATE CHANGE It is now evident that some climate change signals are already making themselves apparent in the GHA subregion. They include:
Temperature rises; Decreasing rainfall trendsMelting and retreat of mountain glaciers; Increasing frequency of ENSO events (extreme climate
events- Frequent occurrence of droughts and Floods);These change signals have been associated with the following
observed impacts: Sea level rises Resurgences of some diseases; Rivers becoming more seasonal or disappearing altogether; Shrinking of lake levels and sizes; and Shifts in rainfall seasons among others.
Shrinking Lake NakuruDrying of Rivers
Mt. Kilimanjaro in 1990 and 2000
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Observed Climate Change Signals in the Eastern Africa Temperature rise
1963
1965
1967
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1971
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1981
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-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
Mbeya Minimum Temperature
year
Tmin
ano
mal
y (°C
)
INDICATORS OF CLIMATE CHANGE IN KENYA: OND Rainfall Trends In Kenya
Nyahururu OND rainfall trend
y = -1.393x + 221.61
0.0
100.0
200.0
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700.0
800.0
900.0
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2003
2006
Year
Rai
nfal
l (O
ND
)
y = -1.3197x + 336.22
0.0
200.0
400.0
600.0
800.0
1000.0
1200.0
1950
1953
1956
1959
1962
1965
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1971
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2001
2004
Narok OND rainfall trend
y = - 0.2835x + 187.34
0.0
100.0
200.0
300.0
400.0
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600.0
700.0
800.0
1950
1953
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2001
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Year
Rai
nfal
l (m
m)
Marsabit
Narok
Nyahururu
Nyahururu OND rainfall trend
y = -1.393x + 221.61
0.0
100.0
200.0
300.0
400.0
500.0
600.0
700.0
800.0
900.0
1961
1964
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1982
1985
1988
1991
1994
1997
2000
2003
2006
Year
Rai
nfal
l (O
ND
)
NyahururuNyahururu OND rainfall trend
y = -1.393x + 221.61
0.0
100.0
200.0
300.0
400.0
500.0
600.0
700.0
800.0
900.0
1961
1964
1967
1970
1973
1976
1979
1982
1985
1988
1991
1994
1997
2000
2003
2006
Year
Rai
nfal
l (O
ND
)
Rainfall Trends
0
500
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2000
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Year
Kenya and Tanzania
19801983
19861989
19921995
19982001
20042007
300.0
400.0
500.0
600.0
700.0
800.0
900.0
1000.0MSABAHA
YEARS
SEAS
ON
AL T
OTA
LS
Trends of Maximum and Minimum Temperature over Mandera
Rainfall Trends in Moyale
Rainfall Trends in the GHA
Vulnerability of the African Continent
Climate Projections• The future climate will be determined
partly by the amount of the greenhouse gases that will be emitted, which in turn is determined by future developments in the economy, technology, and population growth. • Population size, affluence, fossil fuel
consumption, and energy efficiency all have tremendous influence on the overall global emissions.
Family of Scenarios
A1FI (fossil fuel intensive), A1B (balanced), and A1T (predominantly non-fossil fuel)
Future Climate Projections• By 2100, temperature will rise 1.8 – 4 ˚C. • Sea level will rise: 18 - 59 cm. • Oceans will become more acidic.• Hot extremes, heat waves and heavy precipitation
events will become more frequent. • There will be more precipitation at high latitudes
and less precipitation in most subtropical regions.• Tropical cyclones (typhoons and hurricanes) will
become more intense.
Temperature and Precipitation Changes over Africa
Temperature and precipitation changes over Africa. Differences between 1980-1999 and 2080-2099, averaged over 21 GCMs
Projected Impacts of Climate Change• Climate variability and climate
change are already a threat to food security.
• Frequent droughts mean famines as a result of loss in livelihoods.
• Temperature rises have been accompanied by an increase in vector-borne diseases such as highland malaria, typhoid and cholera.
• Decrease in length of growing season, and areas suitable for rain-fed agriculture. Areas with >20% loss in length of growing season by
2050
• The severe impacts associated with extreme climate events in the various sub-sectors can be reduced through good understanding of the climate patterns/events, enhanced monitoring, early warning, effective and timely dissemination of early warning products and awareness creation on the usefulness of climate information and prediction products.
Reducing Climate Impacts
• Examine, Identify and document the extreme weather and climate events that affect the various sectors.
• Develop relevant policies that will factor climate information and prediction products into disaster preparedness and management.
• Encourage closer collaboration between the producers of climate information and the users of these information.
Proposed Activities for reducing climate impacts
• Setup early warning units for disaster preparedness and management within the above sub-sectors
• Build Capacity in the usage, understandability and relevance of climate information products within each of the sectors.
• Document the potential benefits of utilizing climate information products in the sectors.
• Encourage collaborative/joint research amongst the research institutions in addressing the devastating impacts of extreme weather and climate events.
• Document the climate information repackaging needs for the various sectors.
Cont..
Adaptation strategies in the Water Sector• Management of water outflows from dams• More efficient water use• Proper management of water resources• Rain water harvesting • Catchments protection• River bank protection• Soil water conservation measures• Crop diversification• Intercropping so as to spread the risk• Adoption of drought resistant crops• Stocking of hay as well as livestock destocking prior to
drought period and restocking when the season improves• Timely, Efficient and effective early warning systems on
climate anomalies
Adaptation Technologies in Agriculture
Conclusions• Climate change impacts have the
potential to undermine and even, undo progress made in improving the socio-economic well-being of many countries in Africa.• There is need to focus on reducing the
risks associated with the current climate variability and extremes in order to be able to adapt to future changes in climate.
RECOMMENDATIONS• Need to Conduct studies to understand
of local / regional climate systems• Understand and Predict regional
variability / change• Need for mapping regional climate
hazards • Need to Address Regional climate data
gaps, Capacity building needs, Climate modelling and the use of various climate change impact tools.
END
Adapt or PerishTHANK YOU
