Transcript Climate Change_Signals_Oludhe_CRAMx

Climate change signals in the Greater Horn of Africa
and possible adaptation options
Christopher Oludhe
Department of Meteorology
University of Nairobi/ICPAC
THE 3RD CRAM (CROP AND
RANGELAND MONITORING) WORKSHOP IN NAIROBI, 26 - 30TH
September, 2011, RCMRD, Nairobi, Kenya.
Some Definitions
• 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.
The science of climate change
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 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
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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 trends
Melting 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.
Drying of Rivers
Shrinking Lake Nakuru
Mt. Kilimanjaro in 1990 and 2000
Observed Climate Change Signals in the Eastern Africa
Temperature rise
Mbeya
Minimum Temperature
2.5
2.0
1.5
1.0
Tmin anomaly (°C)
0.5
0.0
-0.5
-1.0
-1.5
-2.0
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1999
2001
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-2.5
year
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INDICATORS OF CLIMATE CHANGE IN KENYA: OND Rainfall Trends In
Kenya
Marsabit
1200.0
Nyahururu OND rainfall trend
Nyahururu OND rainfall trend
900.0
Nyahururu
800.0
900.0
1000.0
Rainfall
Rainfall
(OND)
(OND)
700.0
800.0
800.0
600.0
700.0
y = -1.3197x + 336.22
500.0
600.0
600.0
y = -1.393x + 221.61
400.0
500.0
y = -1.393x + 221.61
400.0
300.0
400.0
200.0
300.0
200.0
100.0
200.0
Year
Narok OND rainfall trend
Narok
800.0
700.0
500.0
y = - 0.2835x + 187.34
400.0
300.0
200.0
100.0
Year
2004
2001
1998
1995
1992
1989
1986
1983
1980
1977
1974
1971
1968
1965
1962
1959
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0.0
1950
Rainfall (mm)
600.0
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2001
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1995
1992
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1962
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0.0
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20062006
20032003
20002000
19971997
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Year
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0.0
19611961
0.0
100.0
Rainfall Trends
Kenya and Tanzania
2500
2000
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1000
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Year
MSABAHA
1000.0
SEASONAL TOTALS
900.0
800.0
700.0
600.0
500.0
400.0
YEARS
2007
2004
2001
1998
1995
1992
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1986
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1980
300.0
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.
Visualising Family of Scenarios
Family of Scenarios
A1FI (fossil fuel intensive), A1B (balanced), and A1T (predominantly non-fossil fuel)
Future Climate Projections
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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 rainfed agriculture.
Areas with >20% loss in length of growing season by
2050
Reducing Climate Impacts
• 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.
Proposed Activities for 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.
Cont..
• 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.
Adaptation strategies in the Water Sector
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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.
Adapt or Perish
THANK YOU
END