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CHAPTER FIVE
CLIMATE OF ETHIOPIA AND
THE HORN
Compiled by Behailu Getu.
behilu.getu@wku.edu.et
Objectives
Upon the completion of this chapter, you will be
able to:
Distinguish between weather and climate,
Explain the place to place distribution of
temperature and rainfall in Ethiopia,
❑explain the time to time patterns of temperature
and rainfall in Ethiopia,
Analyze climate and its implications on
biophysical and socioeconomic aspects,
identify the causes, consequences and response
mechanisms of climate change.
2
3
5.1 The concept of weather and climate
Both weather and climate are concepts about
atmospheric conditions. The basic difference on
them is duration and areal coverage.
➢Weather is atmospheric condition observed in a
very specific area with a short term fluctuation,
while
Climate is a prolonged(30-35years) atmospheric
condition observed in a relatively wider geographic
area.
➢Weather condition likely changed hour to hour, in
a daily base or weakly but climate is relatively
permanent.
4
Cont…
➢Climate is average on the patterns of weather
records for at least three decades and even
circumstantial to variations that may occur beyond
the average.
➢Terms in daily meteorology as windy, sunny,
rainy, cloudy… are about Weather patterns and
terms as desert, semi-desert, temperate, alpine, afro-
alpine… are expressions for climate patter.
➢We Ethiopians identify climate as Bereha, Qolla,
Dega, Woina-dega, Wurch etc
Question! to which kind of the above climate
categories your home land can be grouped?
5
5.2 Elements of Weather and Climate
Elements(components) of weather and
climate are the following variables
• Atmospheric temperature (how cold or hot is
the atmosphere)
• Precipitation (any kind of moisture falling from
the atmosphere to the ground, mostly rainfall)
• Air pressure (the weight exerted by the air)
• Humidity (the level or proportion of water vapor
within the atmosphere)
• Sunshine (the duration and intensity of solar heat
as well as light)
• Wind (horizontal motion of air)
6
5.3 Controls of Weather and Climate
The climate and even weather condition of a place
is determined by the collective effect of the
following controlling factors
• Latitude (how far is the place from the equator)
• Altitude (elevation of the place relative to the sea
level)
• Topography (for instance mountain barriers)
• Ocean currents (warming or cooling effect released
from adjacent oceans to the place)
• Wind
• Cloud
• Distance from a certain water body
• Prevalence or absence of vegetation
A. Latitude
• The earth’s rotation axis makes an angle of about 66 ½ ° with the
plane of its orbit around the sun, or about 23 ½ ° from the
perpendicular to the ecliptic plane (This determines the location of
the Tropics of Cancer, Capricorn & the Arctic & Antarctic Circles)
Angle of inclination
of the sun rays
7
8
• Due to inclination of the earths rotational axis by 23 ½ °
the perpendicular nature of solar ray is limited only to the
tropical region (between tropic of cancer and tropic of
Capricorn).
• Section of the earth out of the tropic receives an
oblique solar ray which is weak in intensity. As you
move further away from the equator towards the
poles, less powerful solar insolation is received and
the temperature become colder.
• Compared to those far from the equator, places near
the equator receives:
• High intensity of solar radiation, balanced duration of
day & night, and High level precipitation
.
Heat distribution along latitude
183
➢Ethiopia’s latitudinal
location is within the tropic
particularly between 3ºN
and 15ºN and so has;
✓Adequate access to solar
heat,
✓balanced length of day and
night as well as
✓Adequate distribution of
precipitation.
10
11
Equinoxes
• An “equinox” implies equal duration of the day time and
the night time. Such a phenomena happens when the sun
ray strikes the surface of the earth with an angle of 90º.
• An equinox regularly occurs on two particular days with a
6 months gap each year for all the specific places within
the tropics.
• e.g. 1. places along the equator (0º latitude) have an
equinox phenomena on September 23rd and March 21st .
• e.g. 2. Addis Ababa found with in the tropic at 9ºN
experience an over head sun on April 25 and August 16
Each year. In these two particular days the length of day
and night in Addis is exactly equal i.e. Equinox.
NB: your home land/town even have its own equinox!!
12
• For all the places out of the tropics equinox is
an impossible phenomena. Because the sun
never to have an overhead position out of the
tropical zone.
• As we move pole ward, the tendency to
experience unbalanced length of day and night
increase.
• March 21 marks the onset (first day) of the
spring season for northern hemisphere and it is
known as Vernal (spring) equinox. It is the day
when the point of verticality of sun’s rays
crosses the equator northward.
• Onwards from the vernal equinox for six months, the sun
stays on overhead position to the Northern Hemisphere
section of the tropical world
• September 23rd marks the onset(beginning) of
Autumn season for Northern Hemisphere and it is
known as Autumn equinox.
• It occurs when the sun crosses equator southward.
13
14
Solstice
• A “Solstice” is an event when the overhead sun
appears along the two tropic lines.
• on June 22nd, The sun appears to its highest position
in the noonday sky directly above 23 ½ ( at Tropic
of Cancer).
• This particular date known as the summer Solstice.
It is the astronomical first day of summer in the
Northern Hemisphere.
• Places in the northern hemisphere has maximum tilt
towards the sun to this date experience their longest
daylight session in the year.
• on December 22nd
, The sun appears to its highest position in
the noonday sky directly above 23 ½ºS ( at Tropic of
Capricorn).
• This particular date known as the winter Solstice. It is the
astronomical first day for the Northern Hemisphere winter.
• Places in the southern hemisphere has maximum tilt
towards the sun to this date experience their longest
daylight session in the year.
15
Length of the day on winter and summer solstices in the
northern hemisphere
Latitude 00
200
400
600
900
December 21 12h 00m 10h 48m 9h 8m 5h 33m 0
June 21 12h 13h 12m 14h 52m 18h 27m 24 hr
16
17
B. Altitude
• Altitude is the height of location from the sea
level.
• The atmosphere is directly heated by terrestrial
radiation from below. Therefore, the place near
the sea level record higher temperature than
the place situated at higher elevations.
• For this reason there is a general decrease in
temperature with an increase in elevation. The
rate of decrease of temperature with height
termed as the normal lapse rate (6.5°𝐶 per
1000m).
• The lapse rate is limited to the lower layer of
the atmosphere (the troposphere).
• Example:- if the altitude of a given
mountain is 4070m above mean sea level
and the temperature at the sea level is
20°𝐶. Rejecting the effect of all other
climate controlling factors, temperature at
the top of the mountain expected to be:
1000m = 6.50c
4070m = ?
1000m
(4070mx6.5°𝐶)=26.450 C (colder
than the temperature at sea level.
That means 20°𝑪 - (26.45) = -6.450 c
• However, altitude may not be the only
factor to determine temperature at the top
of this mountain. So you possibly have an
actual temperature below or above -
6.45°𝐶 depending on the effect of the
other factors.
-6.45° c
18
20°𝐶
19
Types of lapse rate
i. Dry adiabatic laps rate
• Dry adiabatic lapse rate is the rate at which the
temperature of an air parcel changes in response
molecular expansion associated with increase or
decrease in altitude.
• When air rises, it expands because there is less
weight of air upon it. Thus, if a mass of dry air
at sea level rises to an altitude of about 18,000ft
(5486.22 meters), the pressure upon it is
reduced by nearly half and consequently its
volume is doubled.
• As long as the air in the parcel
is unsaturated (the relative
humidity is less than 100
percent), the rate of adiabatic
cooling remains constant.
• More precisely, if the upward
movement of air does not
produce condensation, then the
energy exerted by expansion
process will cause the
temperature of the mass to fall
at the constant dry adiabatic
lapse rate i.e. 10°C for every
1000 m increase in elevation.
• This rate also applies on the
process in opposite direction as
adiabatic warming.
20
ii. Wet Adiabatic laps rate
• If the air becomes saturated
(100%
longer
humid) it
cool at
will no
the dry
adiabatic rate due to the latent
heat in the water vapor
carried by the air.
• A saturated air containing
water droplets would warm
(if it moves down ward) or
cool (if it moves upward) to a
rate of approximately 5°c per
1000meters change in
elevation. This rate is called
wet adiabatic laps rate.
21
22
iii. Environmental lapse rate or
Atmospheric lapse late
• This refers to the actual, observed change of temperature
with altitude due to the collective effect of: nearness to
the source of terrestrial emission, abundance of
greenhouse gases and dust particles.
• Atmosphere near to the earths surface contains more
water vapor and dust, which causes it to be a more
efficient absorber of terrestrial radiation to be warmer
compared to the thinner upper section.
• In this regard temperature fall at a rate of 6.5°C/1000 meters
upward and the revers is true.
• This decrease in temperature upward from the earth's
surface normally prevails throughout the lower
atmosphere.
C. Distance from the Sea
• Another factor that influences
atmospheric temperature is
the location of a place with
respect to the sea.
• Compared to the land, the sea
gets heated slowly and losses
heat slowly.
• Land heats up and cools
down quickly. Therefore, the
variation in temperature over
the sea is less compared to
land.
• places situated near the sea
come under the moderating
influence of the sea (sea
breezes) which minimize
their temperature. 197
24
D. Ocean current
➢Currents are movements of ocean water in a
continuous flow, created largely by surface winds
but also partly by temperature and salinity
gradients, Earth’s rotation, and tides.
➢Major current systems typically flow clockwise in
the northern hemisphere & counterclockwise in
the southern hemisphere, in circular patterns that
often trace the coastlines.
➢Ocean currents act much like a conveyor belt,
transporting warm water and precipitation from the
equator toward the poles and cold water from the
poles back to the tropics.
➢Thus, ocean currents regulate global climate,
helping to counteract the uneven distribution of
solar radiation reaching Earth's surface.
• Similarly, the places located on the cost where
the warm ocean currents flow record higher
temperature & rainfall than the places located on
the coast where the cold currents flow.
25
26
5.4 Spatial Distribution of Temperature in
Ethiopia
• Altitude and Latitude, are the primary determinant of
temperature in Ethiopia.
• Global winds pattern, cloud and humidity with varying
magnitude have also significant impacts on temperature
condition in Ethiopia.
• The location of Ethiopia at close proximity to equator
make every part of the country to experience overhead
sun twice a year.
• However, in Ethiopia, as it is a highland country, tropical
temperature conditions have no full spatial coverage.
Cont…
• From the peripheries(border lowlands) towards
the center of the country, the land gradually
rise in altitude considerably.
• Thus, temperature decreases towards the
interior highlands.
• This makes tropical kind of climate limited to
the border lowlands and Non-tropical (cool or
fairly cold) climate experienced all over the
highland.
• Mean annual temperature varies from over
30ºC in the tropical lowlands to less than 10ºc
at the very high altitudes. 201
28
• The Bale Mountains, choke mountain ranges,
Semien mountain ranges are among highlands
where lowest mean annual temperatures are
recorded even below 0ºC.
• While the vast plateau lands all over the
highlands (parts of Tigray, Gonder, Gojjam,
Wollo, Shewa, SW-highlands, Arsi, Bali and
Hararghe) have a moderate or mild
temperature distribution.
29
The highest mean annual temperature in the
country is recorded in the Afar Depression.
Moreover:
➢ North-western lowlands( Humera & Metema),
➢Western lowlands(Abay-Dinder & Baro-Akbo)
➢south-eastern lowlands(Ogaden, Elkerie &
Borena).
experiences mean maximum temperatures of
more than 30ºC.
Agro-ecological zone of Ethiopia
30
31
5.5 Temporal Distribution of Temperature in
Ethiopia
• The temporal(seasonal) distribution of
temperature in Ethiopian is characterized
by extremes.
▪ The major controls determining its
distributions are latitude, wind and cloud
cover.
• In the tropics, the daily range of
temperature is higher and the annual range
is small, whereas the reverse is true in the
temperate latitudes.
32
• In Ethiopia, as in all places in the
tropics, the air is frost free and changes
in solar angles are small making intense
solar radiation.
➢Ethiopia’s daily temperatures are more
extreme (very low or very high) than its
annual averages.
➢Daily maximum temperature varies
from more than 37ºC over the eastern
lowlands to lower of about 10ºC over
the northwestern and southwestern
highlands.
33
• The variation in the amount of solar
radiation received daily is small throughout
the year.
• As already explained, temperature is high
during the daytime in some places, and is
considerably reduced at night resulting
maximum difference in the daily range.
34
But in case of monthly averages, variation is
minimal and the annual range of temperature is
small. This holds true in both the highlands and
lowlands.
• In Ethiopia and elsewhere in the Horn,
temperature shows seasonal variations.
For example, months from March to June in
Ethiopia have records of highest temperatures.
Conversely, low temperatures are recorded from
November to February.
35
• It is not easy to observe distinct variation in
temperature between seasons as the sun is
always high in the tropics.
• However, there is a slight temperature increase
in summer and decline in winter.
• Southern part of Ethiopia receives highest
records of temperature in autumn and spring
following the relative shift of the sun; whereas
in the northern part of the country, summer
season is characterized by higher temperature.
It has to be noted that certain seasons should
have special considerations. For instance,
considerable part of Ethiopia experience reduced
temperature for most of the seasons due to
prevailing cloud cover.
36
5.6 Spatial and temporal Distribution of
Rainfall
• Rainfall distribution in Ethiopia is
characterized by complexities.
• It is governed by position of Inter Tropical
Convergence Zone (ITC), pressure
Trade Winds, Ethiopia's topography
cells,
and
location.
• Inter Tropical Convergence Zone(ITCZ) is
the converging zone for Northeast Trade
winds and the Equatorial westerlies.
• ITCZ is a low-pressure zone occurred at the zone of
overhead sun. 211
38
➢As the overhead position of the sun apparently
oscillates between the tropic of Cancer and tropic
of Capricorn season to season the ITCZ oscillates
parallel.
ITCZ causes variation in the Wind patterns over Ethiopia
and the Horn throughout the seasons.
➢During summer (June, July, August) (mid June –
mid September) position of the overhead sun and
ITCZ appears in the latitude North of Ethiopia as a
result Equatorial westerly's or Guinea monsoon
which are warm & moist reaches Ethiopia from
equatorial Atlantic.
➢These winds facing the western high relief of
Ethiopia drop their moisture all over the western
Ethiopian physiographic region.
39
• However, the northern rift valley and the eastern
physiographic region become rain shadow from these
winds.
➢During Autumn (September, October and
November)
• From mid September- mid December) : the ITCZ
shifts towards the equator weakening the equatorial
westerlies.
• During this season, the south easterlies from Indian
ocean showers the lowlands in southeastern part of
Ethiopia.
40
➢During winter (December, January &
February)
• From mid December - mid March
overhead position of the sun and ITCZ
shifts south of equator towards Tropic of
Capricorn. So, Northeast Trade Winds
from northern Asia (cold and dry)
Crosses all over Ethiopia towards
southern tropic. This makes dry and
relatively cold winter all over Ethiopia
exceptional to Afar and parts of Eritrean
coasts.
Note: The Northeast trade winds crossing the Red
Sea carry very little moisture and supplies rain only
to the Afar lowlands and the Red Sea coastal areas.
41
42
➢In Spring (March, April and May)
• From mid March- mid June the overhead sun
appears directly on the equator while shifting to
the north from south.
• The shift of the ITCZ, results in longer days and
more direct solar radiation providing warmer
weather for the northern world. In this season, the
effect of the northeast trade wind is very much
reduced. Conversely, the south easterlies from the
Indian Ocean provide rain to the highlands of Bale
& all the adjacent places
43
5.7 Rainfall Regions of Ethiopia
➢Summer rainfall region
The Summer rainfall region comprises almost all
parts of the country, except the southeastern and
northeastern lowlands. Ethiopia experiences most of
its rain during summer (kiremt).
➢Year-round rainfall region
southwestern part of the Ethiopia has a prolonged
rainy season than any other part of the country. The
wetness of this region is particularly due to the
prevalence of the moist equatorial Westerly winds or
Guinea Monsoons.
➢ Autumn and Spring rainfall regions
South eastern lowlands of Ethiopia receive rain during autumn and
spring seasons.
The southeastern Ethiopian highlands receive their big rain during
spring and a little rain in Autumn.
➢ Winter rainfall region
• the Red sea escarpments and some parts of the Afar region receive
their main rain.
1
44
2
3
4
1
2
3
4
5
5
45
5.8 Agro-ecological Zones of Ethiopia
The contrasting altitude and climatic conditions,
enriches Ethiopia to possesses divers agro-
climatic zones. There are five major climatic
zones traditionally identified as Bereha, Kolla,
Woina Dega, Dega and Wurch.
i.The Wurch climate Zone
➢Altitude higher than 3,200 m a.s.l,
➢Mean annual temperature of less than 10°C.
e.g. Ras Dashen, Guna, Megezez in North Shoa, Batu,
Choke, Abune Yoseph etc.
46
ii. Dega climate Zone
➢altitude is between 2300 and 3200 m.a.s.l
➢Mean annual temperature is 10-15°C
➢have relatively higher temperature and lower
altitude compared to the wurch Zones.
➢Dega-zone is well inhabited and has
human settlement patterns
➢Rainfall is reliable for agriculture
➢No vector-borne diseases such as malaria.
dense
47
iii. Weyna Dega climate Zone
➢This zone has warmer temperature and moderate
rainfall.
➢ Average annual temperature ranges between 15°C &
20°C
➢It lies between 1500-2,300 m.a.s.l
➢It covers more than 26% of the land area of
Ethiopia.
➢The temperature and rainfall of woina dega zone is
highly suitable for majority of crops grown in
Ethiopia.
➢This zone includes most of the agricultural land.
➢The Weyna Dega zone has two growing seasons.
48
iv. Kolla climate Zone
➢the geographic peripheries in south, southeast, west
and northeastern part are mainly in this category.
➢Kolla is the climate of the hot lowlands with an
altitudinal range of 500 to 1500 m.a.s.l
➢Average annual temperature ranges between 20°C
and 30°C.
➢Although mean annual rainfall is erratic, it can be as
high as 1500 mm in the wet western lowlands of
Gambella.
➢ Rainfall is highly variable from year to year.
➢The region is a transition between the hot arid
(Bereha) and the humid climates (Woina Dega).
49
v. Bereha climate Zone
➢Bereha is the hot arid climate of the desert
lowlands.
➢it largely confined to lowland areas with
altitude of lower than 500 meters.
➢Its average annual rainfall is less than 200
mm, and
➢average annual temperature is over 30°C
50
Zones Altitude (m) Mean
annual
rainfall
(mm)
Length of
growing
periods
(days)
Mean
annual
temperatur
e (0C)
Area
share
(%)
Wurch (cold to
moist)/Alpine or
Afro Alpine
>3,300 900-2,200 211–365 Below 10 0.98
Dega (cool to
humid)/Temprate
2,300 - 3,300 900-1,200 121–210 10–15 9.94
Weyna Dega (cool
sub humid)/
Subtropical
1,500 - 2300 800-1,200 91–120 15 – 20 26.75
Kola (Warm
semiarid) /Tropical
500 - 1,500 200-800 46–90 20– 30 52.94
Berha (Hot arid)
/Desert
<500 Below 200 0–45 >30 9.39
Agro Ecological Zones of Ethiopia
51
5.9 Climate Change/Global Warming: Causes,
Consequences and Response Mechanisms
What is climate change?
• Climate change refers to a change in the state of
the climate that was known and can be
identified before(e.g. using statistical tests).
• Changes in the variability of its properties that
persists for an extended period, typically
decades or longer.
• It refers to any change in climate over time, due
to either natural variability or human activities.
52
Current Trends of Climate in Ethiopia
• Besides the normal spatial and temporal
variations in different parts of the country,
Ethiopian experiences climate extremes such
as drought, flood etc.
• Ethiopia ranked 5th out of 184 countries in
terms of its vulnerability to drought.
• 12 extreme drought events were recorded between
1900 and 2010 in the country .
• Among the 12, seven of the drought events
occurred since 1980.
53
• The majority of these drought phenomena resulted
in famines. The severe drought of 2015-2016 was
exacerbated by the strongest El Nino
• that caused successive harvest failures and
widespread livestock deaths in some regions.
Trends in Temperature Variability
• Over the last decades, Ethiopia has experienced
climatic changes. Mean annual temperature has
shown 0.2°C to 0.28°C rise per decade over the
last 40-50 years.
54
• A rise in average temperature of about 1.3°C has
been observed between 1960 and 2006. The rise
has spatial and temporal variation. Higher rise in
temperature was noted in drier areas in northeast
and southeast part of the country.
• Notably the variability is higher in July-
September. The number of ‘hot days’ and ‘hot
nights’ has also shown increment. Consequently,
the country’s minimum temperature has increased
with 0.37°C to 0.4°C per decade.
55
Trends in Rainfall Variability
• Precipitation has remained fairly stable over the
last 50 years when averaged over the country.
• However, these averages do not reflect local
conditions. Rainfall variability is increasing (and
predictability is decreasing) in many parts of the
country.
• In some regions, total average rainfall is showing
decline. For instance, parts of southern,
southwestern and south-eastern regions receiving
Spring and Summer rainfall have shown decline
by 15-20%between 1975 and 2010.
56
• This has strong implications for crop production,
which becomes clear when assessing the change
in areas that receive sufficient rain to support
crop production.
• Changes in temperature and rainfall increase the
frequency and severity of extreme events. Major
floods have been a common occurrence, leading
to loss of life and property in numerous parts of
the country. Warming has exacerbated droughts,
and desertification in the lowlands of the country
is expanding.
57
5.9.1 Causes of Climate Change
The causes of climate change are generally
categorized as anthropogenic/manmade and natural
causes.
A. Natural Causes
Climate change has many natural causes, such as
➢Earth orbital changes: The earth is tilted at an
angle of 23.5° to the perpendicular plane of its
orbital path. Changes in the tilt of the earth can
lead to small but climatically important changes
in the strength of the seasons. More tilt means
warmer summers and colder winters.
58
➢The variation on global heat Energy
Budget: Although the Sun’s energy output
appears constant, small changes over an
extended period of time can lead to climate
changes. Since the Sun was born, 4.55
billion years ago, it has been very gradually
increasing its amount of radiation so that it is
now 20% to 30% more intense than it was
once.
59
eruptions: volcanic eruption
sulphur
➢Volcanic
releases
dioxide,
large
carbon
volumes of
dioxide, water vapor,
dust, and ash into the atmosphere. The
release of large volume of gases and ash
can increase planetary reflectivity causing
atmospheric cooling.
➢Continental drifts towards the pole or
towards equator
60
B. Anthropogenic Causes
The growing influence of human activities on the
environment is being increasingly recognized, and
concern over the potential for global warming
caused by such anthropogenic effects is growing.
The warming of the planet in the past 50 years is
majorly driven by human activities.
➢The industrial activities that our modern
civilization depends upon have raised
atmospheric carbon dioxide levels from 280 parts
per million to 400 parts per million in the last
150 years.
61
➢Human induced greenhouse gases such as
carbon dioxide, methane and nitrous oxide
have caused much of the observed increase in
Earth's temperatures over the past 50 years.
➢The major
greenhouse
gases that contribute to the
effect include Water
Carbon dioxide (CO2), Methane,
vapor,
Nitrous
oxide, Chlorofluorocarbons (CFCs).Although,
methane is less abundant in atmosphere, it is
by far more active greenhouse gas than carbon
dioxide.
➢The decomposition of
wastes in landfills,
agriculture,
digestion and
management,
ruminant
manure
synthetic
compounds
manufacturing, clearing
of land for agriculture,
industrial activities, and
other human activities
have increased
concentrations of
greenhouse gases.
62
63
5.9.2 Consequences of Climate Change
• In many parts of the world, climate change has
already caused loss of life, damaging property
and affecting livelihoods.
• The impact of climate change is higher in low
income countries, since they have limited
capacity to cope with the changes. Some of the
consequences of the changing climate include:
64
• Impacts on human health: The change can
cause increased heat related mortality and
morbidity, greater frequency of infectious disease
epidemics following floods and storms, and
substantial health effects following population
displacement to escape extreme weather events.
Climate change also raises the incidence malaria.
• Impact on Agriculture: changes in temperature and
rainfall patterns as well as significantly affect
agricultural production. Climate change increases
physiological stress and fodder quality and
availability.
65
• Impact on water resources: Climate change is
leading to melting of snow and glaciers that
increases rise in sea level, increase drought and
floods, distorts wind flow pattern, decreases
water table. More frequent and longer droughts
reduce the amount of run-off into rivers, streams
and lakes.
• Impact on Ecosystem: climate change affects the
success of species, population, and community
adaptation. The rate of climatic warming may
exceed the rate of shifts in certain range species,
these species could be seriously affected or even
disappear because they are unable to resist.
66
5.9.3 Response Mechanisms to Climate
change
• Climate change is one of the most complex issues
facing us today. So even if we stopped emitting
all greenhouse gases today, global warming and
climate change will continue as it has natural
source of emission.
• Hence, there has to be response mechanism to
reduce the impact of extreme events. There are
three major response mechanisms to climate
change namely mitigation, adaptation and
resilience.
67
Mitigation and its Strategies
• Mitigation measures are those actions that are
taken to reduce and control greenhouse gas
emissions changing the climate.
• Moreover, it implies reducing the flow of heat
trapping greenhouse gases into the atmosphere,
either by reducing sources of these gases or
enhancing the “sinks” that accumulate and store
these gases (such as the oceans, forests and soil)
68
➢The goal of mitigations is to avoid significant
human interference with the climate system.
There are some mitigation measures that can be
taken to avoid the increase of pollutant
emissions:-
✓Practice Energy efficiency
✓ Increase the use of renewable energy such as
solar
✓ Efficient means of transport implementation:
electric public transport, bicycle, shared cars etc.
69
Adaptation and Strategies
• Throughout history, people and societies have
adjusted to and coped with changes in climate and
extremes with varying degrees of success.
• Adaptation is simply defined as adapting to life in a
changing climate. It involves adjusting to actual or
expected future climate.
• The goal is to reduce our vulnerability to the harmful
effects of climate change such as extreme weather
events or food insecurity.
• It also encompasses making the most of any potential
beneficial opportunities associated with climate
change (for example, longer growing seasons or
increased yields in some regions).
70
❖Some of the major adaptation strategies include:
✓ building flood defenses,
✓plan for heat waves and higher temperatures,
✓ installing water-permeable pavements to better
deal with floods and storm water
✓improve water storage and use are some of
measures taken by cities and towns.
✓landscape restoration and reforestation,
✓ flexible and diverse cultivation to be prepared for
natural catastrophes
✓preventive and precautionary measures
(evacuation plans, health issues, etc.)
71

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Capter 5 Climate of Ethiopia and the Horn GeES 1011.pdf

  • 1. 1 CHAPTER FIVE CLIMATE OF ETHIOPIA AND THE HORN Compiled by Behailu Getu. behilu.getu@wku.edu.et
  • 2. Objectives Upon the completion of this chapter, you will be able to: Distinguish between weather and climate, Explain the place to place distribution of temperature and rainfall in Ethiopia, ❑explain the time to time patterns of temperature and rainfall in Ethiopia, Analyze climate and its implications on biophysical and socioeconomic aspects, identify the causes, consequences and response mechanisms of climate change. 2
  • 3. 3 5.1 The concept of weather and climate Both weather and climate are concepts about atmospheric conditions. The basic difference on them is duration and areal coverage. ➢Weather is atmospheric condition observed in a very specific area with a short term fluctuation, while Climate is a prolonged(30-35years) atmospheric condition observed in a relatively wider geographic area. ➢Weather condition likely changed hour to hour, in a daily base or weakly but climate is relatively permanent.
  • 4. 4 Cont… ➢Climate is average on the patterns of weather records for at least three decades and even circumstantial to variations that may occur beyond the average. ➢Terms in daily meteorology as windy, sunny, rainy, cloudy… are about Weather patterns and terms as desert, semi-desert, temperate, alpine, afro- alpine… are expressions for climate patter. ➢We Ethiopians identify climate as Bereha, Qolla, Dega, Woina-dega, Wurch etc Question! to which kind of the above climate categories your home land can be grouped?
  • 5. 5 5.2 Elements of Weather and Climate Elements(components) of weather and climate are the following variables • Atmospheric temperature (how cold or hot is the atmosphere) • Precipitation (any kind of moisture falling from the atmosphere to the ground, mostly rainfall) • Air pressure (the weight exerted by the air) • Humidity (the level or proportion of water vapor within the atmosphere) • Sunshine (the duration and intensity of solar heat as well as light) • Wind (horizontal motion of air)
  • 6. 6 5.3 Controls of Weather and Climate The climate and even weather condition of a place is determined by the collective effect of the following controlling factors • Latitude (how far is the place from the equator) • Altitude (elevation of the place relative to the sea level) • Topography (for instance mountain barriers) • Ocean currents (warming or cooling effect released from adjacent oceans to the place) • Wind • Cloud • Distance from a certain water body • Prevalence or absence of vegetation
  • 7. A. Latitude • The earth’s rotation axis makes an angle of about 66 ½ ° with the plane of its orbit around the sun, or about 23 ½ ° from the perpendicular to the ecliptic plane (This determines the location of the Tropics of Cancer, Capricorn & the Arctic & Antarctic Circles) Angle of inclination of the sun rays 7
  • 8. 8 • Due to inclination of the earths rotational axis by 23 ½ ° the perpendicular nature of solar ray is limited only to the tropical region (between tropic of cancer and tropic of Capricorn). • Section of the earth out of the tropic receives an oblique solar ray which is weak in intensity. As you move further away from the equator towards the poles, less powerful solar insolation is received and the temperature become colder. • Compared to those far from the equator, places near the equator receives: • High intensity of solar radiation, balanced duration of day & night, and High level precipitation
  • 10. ➢Ethiopia’s latitudinal location is within the tropic particularly between 3ºN and 15ºN and so has; ✓Adequate access to solar heat, ✓balanced length of day and night as well as ✓Adequate distribution of precipitation. 10
  • 11. 11 Equinoxes • An “equinox” implies equal duration of the day time and the night time. Such a phenomena happens when the sun ray strikes the surface of the earth with an angle of 90º. • An equinox regularly occurs on two particular days with a 6 months gap each year for all the specific places within the tropics. • e.g. 1. places along the equator (0º latitude) have an equinox phenomena on September 23rd and March 21st . • e.g. 2. Addis Ababa found with in the tropic at 9ºN experience an over head sun on April 25 and August 16 Each year. In these two particular days the length of day and night in Addis is exactly equal i.e. Equinox. NB: your home land/town even have its own equinox!!
  • 12. 12 • For all the places out of the tropics equinox is an impossible phenomena. Because the sun never to have an overhead position out of the tropical zone. • As we move pole ward, the tendency to experience unbalanced length of day and night increase. • March 21 marks the onset (first day) of the spring season for northern hemisphere and it is known as Vernal (spring) equinox. It is the day when the point of verticality of sun’s rays crosses the equator northward.
  • 13. • Onwards from the vernal equinox for six months, the sun stays on overhead position to the Northern Hemisphere section of the tropical world • September 23rd marks the onset(beginning) of Autumn season for Northern Hemisphere and it is known as Autumn equinox. • It occurs when the sun crosses equator southward. 13
  • 14. 14 Solstice • A “Solstice” is an event when the overhead sun appears along the two tropic lines. • on June 22nd, The sun appears to its highest position in the noonday sky directly above 23 ½ ( at Tropic of Cancer). • This particular date known as the summer Solstice. It is the astronomical first day of summer in the Northern Hemisphere. • Places in the northern hemisphere has maximum tilt towards the sun to this date experience their longest daylight session in the year.
  • 15. • on December 22nd , The sun appears to its highest position in the noonday sky directly above 23 ½ºS ( at Tropic of Capricorn). • This particular date known as the winter Solstice. It is the astronomical first day for the Northern Hemisphere winter. • Places in the southern hemisphere has maximum tilt towards the sun to this date experience their longest daylight session in the year. 15
  • 16. Length of the day on winter and summer solstices in the northern hemisphere Latitude 00 200 400 600 900 December 21 12h 00m 10h 48m 9h 8m 5h 33m 0 June 21 12h 13h 12m 14h 52m 18h 27m 24 hr 16
  • 17. 17 B. Altitude • Altitude is the height of location from the sea level. • The atmosphere is directly heated by terrestrial radiation from below. Therefore, the place near the sea level record higher temperature than the place situated at higher elevations. • For this reason there is a general decrease in temperature with an increase in elevation. The rate of decrease of temperature with height termed as the normal lapse rate (6.5°𝐶 per 1000m). • The lapse rate is limited to the lower layer of the atmosphere (the troposphere).
  • 18. • Example:- if the altitude of a given mountain is 4070m above mean sea level and the temperature at the sea level is 20°𝐶. Rejecting the effect of all other climate controlling factors, temperature at the top of the mountain expected to be: 1000m = 6.50c 4070m = ? 1000m (4070mx6.5°𝐶)=26.450 C (colder than the temperature at sea level. That means 20°𝑪 - (26.45) = -6.450 c • However, altitude may not be the only factor to determine temperature at the top of this mountain. So you possibly have an actual temperature below or above - 6.45°𝐶 depending on the effect of the other factors. -6.45° c 18 20°𝐶
  • 19. 19 Types of lapse rate i. Dry adiabatic laps rate • Dry adiabatic lapse rate is the rate at which the temperature of an air parcel changes in response molecular expansion associated with increase or decrease in altitude. • When air rises, it expands because there is less weight of air upon it. Thus, if a mass of dry air at sea level rises to an altitude of about 18,000ft (5486.22 meters), the pressure upon it is reduced by nearly half and consequently its volume is doubled.
  • 20. • As long as the air in the parcel is unsaturated (the relative humidity is less than 100 percent), the rate of adiabatic cooling remains constant. • More precisely, if the upward movement of air does not produce condensation, then the energy exerted by expansion process will cause the temperature of the mass to fall at the constant dry adiabatic lapse rate i.e. 10°C for every 1000 m increase in elevation. • This rate also applies on the process in opposite direction as adiabatic warming. 20
  • 21. ii. Wet Adiabatic laps rate • If the air becomes saturated (100% longer humid) it cool at will no the dry adiabatic rate due to the latent heat in the water vapor carried by the air. • A saturated air containing water droplets would warm (if it moves down ward) or cool (if it moves upward) to a rate of approximately 5°c per 1000meters change in elevation. This rate is called wet adiabatic laps rate. 21
  • 22. 22 iii. Environmental lapse rate or Atmospheric lapse late • This refers to the actual, observed change of temperature with altitude due to the collective effect of: nearness to the source of terrestrial emission, abundance of greenhouse gases and dust particles. • Atmosphere near to the earths surface contains more water vapor and dust, which causes it to be a more efficient absorber of terrestrial radiation to be warmer compared to the thinner upper section. • In this regard temperature fall at a rate of 6.5°C/1000 meters upward and the revers is true. • This decrease in temperature upward from the earth's surface normally prevails throughout the lower atmosphere.
  • 23. C. Distance from the Sea • Another factor that influences atmospheric temperature is the location of a place with respect to the sea. • Compared to the land, the sea gets heated slowly and losses heat slowly. • Land heats up and cools down quickly. Therefore, the variation in temperature over the sea is less compared to land. • places situated near the sea come under the moderating influence of the sea (sea breezes) which minimize their temperature. 197
  • 24. 24 D. Ocean current ➢Currents are movements of ocean water in a continuous flow, created largely by surface winds but also partly by temperature and salinity gradients, Earth’s rotation, and tides. ➢Major current systems typically flow clockwise in the northern hemisphere & counterclockwise in the southern hemisphere, in circular patterns that often trace the coastlines. ➢Ocean currents act much like a conveyor belt, transporting warm water and precipitation from the equator toward the poles and cold water from the poles back to the tropics. ➢Thus, ocean currents regulate global climate, helping to counteract the uneven distribution of solar radiation reaching Earth's surface.
  • 25. • Similarly, the places located on the cost where the warm ocean currents flow record higher temperature & rainfall than the places located on the coast where the cold currents flow. 25
  • 26. 26 5.4 Spatial Distribution of Temperature in Ethiopia • Altitude and Latitude, are the primary determinant of temperature in Ethiopia. • Global winds pattern, cloud and humidity with varying magnitude have also significant impacts on temperature condition in Ethiopia. • The location of Ethiopia at close proximity to equator make every part of the country to experience overhead sun twice a year. • However, in Ethiopia, as it is a highland country, tropical temperature conditions have no full spatial coverage.
  • 27. Cont… • From the peripheries(border lowlands) towards the center of the country, the land gradually rise in altitude considerably. • Thus, temperature decreases towards the interior highlands. • This makes tropical kind of climate limited to the border lowlands and Non-tropical (cool or fairly cold) climate experienced all over the highland. • Mean annual temperature varies from over 30ºC in the tropical lowlands to less than 10ºc at the very high altitudes. 201
  • 28. 28 • The Bale Mountains, choke mountain ranges, Semien mountain ranges are among highlands where lowest mean annual temperatures are recorded even below 0ºC. • While the vast plateau lands all over the highlands (parts of Tigray, Gonder, Gojjam, Wollo, Shewa, SW-highlands, Arsi, Bali and Hararghe) have a moderate or mild temperature distribution.
  • 29. 29 The highest mean annual temperature in the country is recorded in the Afar Depression. Moreover: ➢ North-western lowlands( Humera & Metema), ➢Western lowlands(Abay-Dinder & Baro-Akbo) ➢south-eastern lowlands(Ogaden, Elkerie & Borena). experiences mean maximum temperatures of more than 30ºC.
  • 30. Agro-ecological zone of Ethiopia 30
  • 31. 31 5.5 Temporal Distribution of Temperature in Ethiopia • The temporal(seasonal) distribution of temperature in Ethiopian is characterized by extremes. ▪ The major controls determining its distributions are latitude, wind and cloud cover. • In the tropics, the daily range of temperature is higher and the annual range is small, whereas the reverse is true in the temperate latitudes.
  • 32. 32 • In Ethiopia, as in all places in the tropics, the air is frost free and changes in solar angles are small making intense solar radiation. ➢Ethiopia’s daily temperatures are more extreme (very low or very high) than its annual averages. ➢Daily maximum temperature varies from more than 37ºC over the eastern lowlands to lower of about 10ºC over the northwestern and southwestern highlands.
  • 33. 33 • The variation in the amount of solar radiation received daily is small throughout the year. • As already explained, temperature is high during the daytime in some places, and is considerably reduced at night resulting maximum difference in the daily range.
  • 34. 34 But in case of monthly averages, variation is minimal and the annual range of temperature is small. This holds true in both the highlands and lowlands. • In Ethiopia and elsewhere in the Horn, temperature shows seasonal variations. For example, months from March to June in Ethiopia have records of highest temperatures. Conversely, low temperatures are recorded from November to February.
  • 35. 35 • It is not easy to observe distinct variation in temperature between seasons as the sun is always high in the tropics. • However, there is a slight temperature increase in summer and decline in winter. • Southern part of Ethiopia receives highest records of temperature in autumn and spring following the relative shift of the sun; whereas in the northern part of the country, summer season is characterized by higher temperature.
  • 36. It has to be noted that certain seasons should have special considerations. For instance, considerable part of Ethiopia experience reduced temperature for most of the seasons due to prevailing cloud cover. 36
  • 37. 5.6 Spatial and temporal Distribution of Rainfall • Rainfall distribution in Ethiopia is characterized by complexities. • It is governed by position of Inter Tropical Convergence Zone (ITC), pressure Trade Winds, Ethiopia's topography cells, and location. • Inter Tropical Convergence Zone(ITCZ) is the converging zone for Northeast Trade winds and the Equatorial westerlies. • ITCZ is a low-pressure zone occurred at the zone of overhead sun. 211
  • 38. 38 ➢As the overhead position of the sun apparently oscillates between the tropic of Cancer and tropic of Capricorn season to season the ITCZ oscillates parallel. ITCZ causes variation in the Wind patterns over Ethiopia and the Horn throughout the seasons. ➢During summer (June, July, August) (mid June – mid September) position of the overhead sun and ITCZ appears in the latitude North of Ethiopia as a result Equatorial westerly's or Guinea monsoon which are warm & moist reaches Ethiopia from equatorial Atlantic. ➢These winds facing the western high relief of Ethiopia drop their moisture all over the western Ethiopian physiographic region.
  • 39. 39 • However, the northern rift valley and the eastern physiographic region become rain shadow from these winds. ➢During Autumn (September, October and November) • From mid September- mid December) : the ITCZ shifts towards the equator weakening the equatorial westerlies. • During this season, the south easterlies from Indian ocean showers the lowlands in southeastern part of Ethiopia.
  • 40. 40 ➢During winter (December, January & February) • From mid December - mid March overhead position of the sun and ITCZ shifts south of equator towards Tropic of Capricorn. So, Northeast Trade Winds from northern Asia (cold and dry) Crosses all over Ethiopia towards southern tropic. This makes dry and relatively cold winter all over Ethiopia exceptional to Afar and parts of Eritrean coasts.
  • 41. Note: The Northeast trade winds crossing the Red Sea carry very little moisture and supplies rain only to the Afar lowlands and the Red Sea coastal areas. 41
  • 42. 42 ➢In Spring (March, April and May) • From mid March- mid June the overhead sun appears directly on the equator while shifting to the north from south. • The shift of the ITCZ, results in longer days and more direct solar radiation providing warmer weather for the northern world. In this season, the effect of the northeast trade wind is very much reduced. Conversely, the south easterlies from the Indian Ocean provide rain to the highlands of Bale & all the adjacent places
  • 43. 43 5.7 Rainfall Regions of Ethiopia ➢Summer rainfall region The Summer rainfall region comprises almost all parts of the country, except the southeastern and northeastern lowlands. Ethiopia experiences most of its rain during summer (kiremt). ➢Year-round rainfall region southwestern part of the Ethiopia has a prolonged rainy season than any other part of the country. The wetness of this region is particularly due to the prevalence of the moist equatorial Westerly winds or Guinea Monsoons.
  • 44. ➢ Autumn and Spring rainfall regions South eastern lowlands of Ethiopia receive rain during autumn and spring seasons. The southeastern Ethiopian highlands receive their big rain during spring and a little rain in Autumn. ➢ Winter rainfall region • the Red sea escarpments and some parts of the Afar region receive their main rain. 1 44 2 3 4 1 2 3 4 5 5
  • 45. 45 5.8 Agro-ecological Zones of Ethiopia The contrasting altitude and climatic conditions, enriches Ethiopia to possesses divers agro- climatic zones. There are five major climatic zones traditionally identified as Bereha, Kolla, Woina Dega, Dega and Wurch. i.The Wurch climate Zone ➢Altitude higher than 3,200 m a.s.l, ➢Mean annual temperature of less than 10°C. e.g. Ras Dashen, Guna, Megezez in North Shoa, Batu, Choke, Abune Yoseph etc.
  • 46. 46 ii. Dega climate Zone ➢altitude is between 2300 and 3200 m.a.s.l ➢Mean annual temperature is 10-15°C ➢have relatively higher temperature and lower altitude compared to the wurch Zones. ➢Dega-zone is well inhabited and has human settlement patterns ➢Rainfall is reliable for agriculture ➢No vector-borne diseases such as malaria. dense
  • 47. 47 iii. Weyna Dega climate Zone ➢This zone has warmer temperature and moderate rainfall. ➢ Average annual temperature ranges between 15°C & 20°C ➢It lies between 1500-2,300 m.a.s.l ➢It covers more than 26% of the land area of Ethiopia. ➢The temperature and rainfall of woina dega zone is highly suitable for majority of crops grown in Ethiopia. ➢This zone includes most of the agricultural land. ➢The Weyna Dega zone has two growing seasons.
  • 48. 48 iv. Kolla climate Zone ➢the geographic peripheries in south, southeast, west and northeastern part are mainly in this category. ➢Kolla is the climate of the hot lowlands with an altitudinal range of 500 to 1500 m.a.s.l ➢Average annual temperature ranges between 20°C and 30°C. ➢Although mean annual rainfall is erratic, it can be as high as 1500 mm in the wet western lowlands of Gambella. ➢ Rainfall is highly variable from year to year. ➢The region is a transition between the hot arid (Bereha) and the humid climates (Woina Dega).
  • 49. 49 v. Bereha climate Zone ➢Bereha is the hot arid climate of the desert lowlands. ➢it largely confined to lowland areas with altitude of lower than 500 meters. ➢Its average annual rainfall is less than 200 mm, and ➢average annual temperature is over 30°C
  • 50. 50 Zones Altitude (m) Mean annual rainfall (mm) Length of growing periods (days) Mean annual temperatur e (0C) Area share (%) Wurch (cold to moist)/Alpine or Afro Alpine >3,300 900-2,200 211–365 Below 10 0.98 Dega (cool to humid)/Temprate 2,300 - 3,300 900-1,200 121–210 10–15 9.94 Weyna Dega (cool sub humid)/ Subtropical 1,500 - 2300 800-1,200 91–120 15 – 20 26.75 Kola (Warm semiarid) /Tropical 500 - 1,500 200-800 46–90 20– 30 52.94 Berha (Hot arid) /Desert <500 Below 200 0–45 >30 9.39 Agro Ecological Zones of Ethiopia
  • 51. 51 5.9 Climate Change/Global Warming: Causes, Consequences and Response Mechanisms What is climate change? • Climate change refers to a change in the state of the climate that was known and can be identified before(e.g. using statistical tests). • Changes in the variability of its properties that persists for an extended period, typically decades or longer. • It refers to any change in climate over time, due to either natural variability or human activities.
  • 52. 52 Current Trends of Climate in Ethiopia • Besides the normal spatial and temporal variations in different parts of the country, Ethiopian experiences climate extremes such as drought, flood etc. • Ethiopia ranked 5th out of 184 countries in terms of its vulnerability to drought. • 12 extreme drought events were recorded between 1900 and 2010 in the country . • Among the 12, seven of the drought events occurred since 1980.
  • 53. 53 • The majority of these drought phenomena resulted in famines. The severe drought of 2015-2016 was exacerbated by the strongest El Nino • that caused successive harvest failures and widespread livestock deaths in some regions. Trends in Temperature Variability • Over the last decades, Ethiopia has experienced climatic changes. Mean annual temperature has shown 0.2°C to 0.28°C rise per decade over the last 40-50 years.
  • 54. 54 • A rise in average temperature of about 1.3°C has been observed between 1960 and 2006. The rise has spatial and temporal variation. Higher rise in temperature was noted in drier areas in northeast and southeast part of the country. • Notably the variability is higher in July- September. The number of ‘hot days’ and ‘hot nights’ has also shown increment. Consequently, the country’s minimum temperature has increased with 0.37°C to 0.4°C per decade.
  • 55. 55 Trends in Rainfall Variability • Precipitation has remained fairly stable over the last 50 years when averaged over the country. • However, these averages do not reflect local conditions. Rainfall variability is increasing (and predictability is decreasing) in many parts of the country. • In some regions, total average rainfall is showing decline. For instance, parts of southern, southwestern and south-eastern regions receiving Spring and Summer rainfall have shown decline by 15-20%between 1975 and 2010.
  • 56. 56 • This has strong implications for crop production, which becomes clear when assessing the change in areas that receive sufficient rain to support crop production. • Changes in temperature and rainfall increase the frequency and severity of extreme events. Major floods have been a common occurrence, leading to loss of life and property in numerous parts of the country. Warming has exacerbated droughts, and desertification in the lowlands of the country is expanding.
  • 57. 57 5.9.1 Causes of Climate Change The causes of climate change are generally categorized as anthropogenic/manmade and natural causes. A. Natural Causes Climate change has many natural causes, such as ➢Earth orbital changes: The earth is tilted at an angle of 23.5° to the perpendicular plane of its orbital path. Changes in the tilt of the earth can lead to small but climatically important changes in the strength of the seasons. More tilt means warmer summers and colder winters.
  • 58. 58 ➢The variation on global heat Energy Budget: Although the Sun’s energy output appears constant, small changes over an extended period of time can lead to climate changes. Since the Sun was born, 4.55 billion years ago, it has been very gradually increasing its amount of radiation so that it is now 20% to 30% more intense than it was once.
  • 59. 59 eruptions: volcanic eruption sulphur ➢Volcanic releases dioxide, large carbon volumes of dioxide, water vapor, dust, and ash into the atmosphere. The release of large volume of gases and ash can increase planetary reflectivity causing atmospheric cooling. ➢Continental drifts towards the pole or towards equator
  • 60. 60 B. Anthropogenic Causes The growing influence of human activities on the environment is being increasingly recognized, and concern over the potential for global warming caused by such anthropogenic effects is growing. The warming of the planet in the past 50 years is majorly driven by human activities. ➢The industrial activities that our modern civilization depends upon have raised atmospheric carbon dioxide levels from 280 parts per million to 400 parts per million in the last 150 years.
  • 61. 61 ➢Human induced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in Earth's temperatures over the past 50 years. ➢The major greenhouse gases that contribute to the effect include Water Carbon dioxide (CO2), Methane, vapor, Nitrous oxide, Chlorofluorocarbons (CFCs).Although, methane is less abundant in atmosphere, it is by far more active greenhouse gas than carbon dioxide.
  • 62. ➢The decomposition of wastes in landfills, agriculture, digestion and management, ruminant manure synthetic compounds manufacturing, clearing of land for agriculture, industrial activities, and other human activities have increased concentrations of greenhouse gases. 62
  • 63. 63 5.9.2 Consequences of Climate Change • In many parts of the world, climate change has already caused loss of life, damaging property and affecting livelihoods. • The impact of climate change is higher in low income countries, since they have limited capacity to cope with the changes. Some of the consequences of the changing climate include:
  • 64. 64 • Impacts on human health: The change can cause increased heat related mortality and morbidity, greater frequency of infectious disease epidemics following floods and storms, and substantial health effects following population displacement to escape extreme weather events. Climate change also raises the incidence malaria. • Impact on Agriculture: changes in temperature and rainfall patterns as well as significantly affect agricultural production. Climate change increases physiological stress and fodder quality and availability.
  • 65. 65 • Impact on water resources: Climate change is leading to melting of snow and glaciers that increases rise in sea level, increase drought and floods, distorts wind flow pattern, decreases water table. More frequent and longer droughts reduce the amount of run-off into rivers, streams and lakes. • Impact on Ecosystem: climate change affects the success of species, population, and community adaptation. The rate of climatic warming may exceed the rate of shifts in certain range species, these species could be seriously affected or even disappear because they are unable to resist.
  • 66. 66 5.9.3 Response Mechanisms to Climate change • Climate change is one of the most complex issues facing us today. So even if we stopped emitting all greenhouse gases today, global warming and climate change will continue as it has natural source of emission. • Hence, there has to be response mechanism to reduce the impact of extreme events. There are three major response mechanisms to climate change namely mitigation, adaptation and resilience.
  • 67. 67 Mitigation and its Strategies • Mitigation measures are those actions that are taken to reduce and control greenhouse gas emissions changing the climate. • Moreover, it implies reducing the flow of heat trapping greenhouse gases into the atmosphere, either by reducing sources of these gases or enhancing the “sinks” that accumulate and store these gases (such as the oceans, forests and soil)
  • 68. 68 ➢The goal of mitigations is to avoid significant human interference with the climate system. There are some mitigation measures that can be taken to avoid the increase of pollutant emissions:- ✓Practice Energy efficiency ✓ Increase the use of renewable energy such as solar ✓ Efficient means of transport implementation: electric public transport, bicycle, shared cars etc.
  • 69. 69 Adaptation and Strategies • Throughout history, people and societies have adjusted to and coped with changes in climate and extremes with varying degrees of success. • Adaptation is simply defined as adapting to life in a changing climate. It involves adjusting to actual or expected future climate. • The goal is to reduce our vulnerability to the harmful effects of climate change such as extreme weather events or food insecurity. • It also encompasses making the most of any potential beneficial opportunities associated with climate change (for example, longer growing seasons or increased yields in some regions).
  • 70. 70 ❖Some of the major adaptation strategies include: ✓ building flood defenses, ✓plan for heat waves and higher temperatures, ✓ installing water-permeable pavements to better deal with floods and storm water ✓improve water storage and use are some of measures taken by cities and towns. ✓landscape restoration and reforestation, ✓ flexible and diverse cultivation to be prepared for natural catastrophes ✓preventive and precautionary measures (evacuation plans, health issues, etc.)
  • 71. 71