climate change impacts in different agro … change impacts in different agro-ecological zones of...

Climate Change Impacts in Different Agro-ecological Zones of West Africa

– Humid Zone

Dr. Anthony C. AnuforomPermanent Representative of Nigeria with WMO

Nigerian Meteorological Agency (NIMET)33 Pope Paul II StreetMaitama District, ABUJA

Nigerian Meteorological Agency (NIMET) Nigerian Meteorological Agency (NIMET) ………… providing weather, climate and water information for sustainablproviding weather, climate and water information for sustainable e development and safety of life and propertydevelopment and safety of life and property

Paper presented at the International Workshop on Adaptation to Climate Change in West African Agriculture at Ouagadougou, Burkina Faso

from 27 – 30 April 2009

Outline of Presentation

• Introduction – Contemporary Issues on Climate Change in Africa

• Humid Zone of West Africa

• Evidence of Effects of Climate Change in the Humid Zone of West Africa.

• Challenges to Adaptation to Climate Change in the region.

• Concluding Remarks


High climate variability and drought in West Africa in the 1970s and 1980s had adverse effect on agriculture, particularly in the Sahel. And, according to IPCC 4th Assessment Report, by 2020….

(i)Between 75 and 250 million people may be exposed to increased water stress due to climate change and this will adversely affect livelihoods in the region.

(ii)The area suitable for agriculture, the length of growing seasonsand yield potential, are expected to decrease due to Climate Change.

(iii) Yields from rain-fed agriculture in some countries could be reduced by up to 50%!

(iv) Africa remains one of the most vulnerable continents to climatevariability and change because of multiple stresses and low adaptive capacity.


Introduction – Contemporary Issues on Climate Change in Africa


Introduction – Contemporary Issues on Climate Change in Africa (contd.)

For the West African sub-region...

(i)Agriculture is critical to the economy. While the world average contribution of the agriculture sector to the Gross Domestic Product (GDP) is only 4.5 %, the sector’s contribution is about 30 % in West Africa.

(ii) In addition to the above, over 65 % of the population in the region is rural, and about 90 % of the rural population directly depends on rain-fed agriculture for income and food security. Therefore reduction in rainfall as predicted by various Climate Models translates to threat to livelihood of the population and the economy of the sub-region.

(iii)The 2005 FAO Global Forest Resources Assessment showed that forest and woodland in Sub Saharan Africa presently cover about 530 million ha, compared to 710 million ha in 1975. This ongoing degradation of natural resources is reducing the resilience of the agro-ecosystems to drought, further undermining the region’s future capacity to cope with climate change.


Introduction

Time series (1941-2001) of average normalized April-October rainfall departure for 20 stations in the West

African Soudano-Sahel zone (11-18N and West of 10E); following methodology of Lamb and Peppler,1992).


Introduction


Humid Zone of West AfricaDefinition

• The zone that supports forests as the typical vegetation cover

• Zone where annual precipitation exceeds evaporation. However, this definition encompasses all areas that are not desert or semi-arid

• Other approaches to delineating the zones include those of Thornthwaite, 1931, 1948; Griffiths and Driscoft, 1982, Oliver and Hidore, 2002 as part of general climatic classifications. Thornthwaite used moisture index to define humid climate as having positive index values


Humid Zone of West Africa (contd.)

Some Characteristics of the Zone

• Consists of forests and forest-savannah transition area.

• Covers about 10% of the West African region, including Liberia and parts of Cameroon, Côte d’Ivoire, Ghana, Guinea, Nigeria, Sierra Leone, and Togo.

• Receives more than 1,500 millimeters of rainfall annually and has a growing period of 7 to 12 months.

• The soils are very acidic and easily degraded without vegetation cover.

• The long rainy season in the zone is favorable to roots crops which contribute significantly the GDP.

• The zone is less favorable for pastoral agriculture.


Humid Zone of West Africa

Is Climate Change Evident in the Humid Zone of West Africa?

SOK KAT

BRKGUS

KANDUT

ZAR

NGU

POT DAM MAI

YEL

JEB

BAU

YOL

KAD

JOSMIN

BID

ILO

LOK MKD

GOM

IBI

JLG

KON

ABU

LAFSHK

BEN ABKENUOGJ

OTU

IKM

AKUOND

ONT

ISYOSB

OWE

ABE

IKEIJB

IBA

WAR

YEN

UMU

CALPHC

2 4 6 8 10 12 14

Longitude (degrees E)

4

6

8

10

12

14

Latit

ude

(deg

rees

N)

SOK KAT

BRKGUS

KANDUT

ZAR

NGU

POT DAM MAI

YEL

JEB

BAU

YOL

KAD

JOSMIN

BID

ILO

LOK MKD

GOM

IBI

JLG

KON

ABU

LAFSHK

BEN ABKENUOGJ

OTU

IKM

AKUOND

ONT

ISYOSB

OWE

ABE

IKEIJB

IBA

WAR

YEN

UMU

CALPHC

2 4 6 8 10 12 14


4

6

8

10

12

14

Latit

ude

(deg

rees

N)

Deviation of 1941 – ’70 Mean onset date of rainy season from the 1911 – ’40 onset dates

Deviation of 1971 – 2000 Mean onset date of rainy season from the 1911 – ’40 onset dates

Late Onset now spreading to many parts of the country

Late onsets of rains in a few places

SOK KAT

BRKGUS

KANDUT

ZAR

NGU

POT DAM MAI

YEL

JEB

BAU

YOL

KAD

JOSMIN

BID

ILO

LOK MKD

GOM

IBI

JLG

KON

ABU

LAFSHK

BEN ABKENUOGJ

OTU

IKM

AKUOND

ONT

ISYOSB

OWE

ABE

IKEIJB

IBA

WAR

YEN

UMU

CALPHC

2 4 6 8 10 12 14


4

6

8

10

12

14

Latit

ude

(deg

rees

N)

SOK KAT

BRKGUS

KANDUT

ZAR

NGU

POT DAM MAI

YEL

JEB

BAU

YOL

KAD

JOSMIN

BID

ILO

LOK MKD

GOM

IBI

JLG

KON

ABU

LAFSHK

BEN ABKENUOGJ

OTU

IKM

AKUOND

ONT

ISYOSB

OWE

ABE

IKEIJB

IBA

WAR

YEN

UMU

CALPHC

2 4 6 8 10 12 14


4

6

8

10

12

14

Latit

ude

(deg

rees

N)

Deviation of 1941 – ‘70 Mean cessation date of rainy season from the 1911 – ’40 cessation dates

Early cessation of rains in and around Ondo/Ilorin

Early cessation of the rains now affect many parts of the country

Deviation of 1971-2000 cessation dates from 1911-’40

2 4 6 8 10 12 14

4

6

8

10

12

14

YE

SO

GU

KA

KT

ZA

KN

MKEB

BA

NG

PT MA

ILSH

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EN

AB

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WR

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OWCB

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JALA

BD

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-2-1.5

-1-0. 5

00.5

11.5

22.5

RAINFALL DEPARTURE ANOMALIES FROM 1991 - 2006 OVERTHE WMO REFERENCE PERIOD 1961 - 1990 IN NIGERIA

SLIGHT DEFECITS OVER AREAS SHADED RED AND SURPLUS OVER GREEN AREAS

Late onset of the rainy season spreading to more areas in the humid zone.

Early cessation of the rains Shorter rainy season Shorter cropping season Water shortages, Drought conditions Desertification conditions spreading, etc

Resulting to ... Changes/shifts in boundaries between agro-ecological

zones and

Progressive depletion of forest resources of West Africa

Threat to food production and security.

Distortion of crop calendar.

Changes in distribution of animal diseases and parasites.

Changes in bio-diversity

Climate Change Effects in the Humid Zone


Climate Change Impacts in the Humid Zone

Livestock impacts

Changes in forage resources; shifts in forests vegetation structure or boundaries; changes in forage quality and quantity; reduction in harvest forage; changes in length of growing season; reduced feed intake and changes in livestock productivity such as milk production, growth rates and weight gain, reproduction; and changes in water quality and quantity, shift in types of herbivores;

Ecological impacts

Alteration in carbon storage capacity of the ecosystem; alterations in greenhouse gas emissions; disturbances in ecosystem functions (e. g. alteration in biogeochemical cycling, incidence of wild fires etc.); changes in soil quality and productivity; changes in biodiversity and changes in habitat suitability for wildfire

Socio-economic impacts

Changes in food production and security (locally and nationally; changes to incomes derived from livestock production, wildlife, and other forest outputs; changes in land use; changes in recreational use of forests and

alteration in scenic quality


Challenges to Adaptation to Climate Change in Humid Zone of West Africa

• Although empirical data (particularly rainfall) indicate shifts in rainfall characteristics in parts of West African Humid Zone, the subject is not yet fully understood.

• NHMSs in the sub-region have key roles to play in providing meteorological information for decision-making and for planning adaptation and mitigation strategies. Unfortunately however, some of these NHMSs are relatively weak in terms of observational infrastructure and manpower.

• There is therefore need for capacity building in climate change observation and analyses with a view to identifying climate risks and generating knowledge and managing climate change risks in agriculture, health, water resources, forestry, etc.

• Meteorological services and products, such as seasonal rainfall predictions and other early warning information, are largely not understood by rural farmers who form the bulk of the workforce in agriculture.

• Although over time, local farmers have evolved indigenous adaptation and mitigation strategies, it is necessary to blend and re-enforce these with scientific knowledge.


Conclusion

• The droughts that occurred in West Africa in the 1970s and 1980s had adverse impact on agriculture and hence the economies of countries in the sub-region Africa, particularly the Sahel.

• IPCC 4th Assessment Report indicates that the area suitable for agriculture, the length of growing seasons and yield potential in Africa, are expected to decrease due to Climate Change. Africa remains one of the most vulnerable continents to climate variability and change because of multiple stresses and low adaptive capacity.

• Up to 10% of West Africa falls within the humid zone. The zone is characterized by high rainfall and forest cover is the typical vegetation.

• Empirical evidence indicates significant change in the rainfall pattern in the humid zone. However, there is inadequate understanding of how climate change will affect West Africa in the coming decades. More research is therefore required to understand how West African agro-ecosystems will respond to climate change; how livelihoods will be affected, with a view to evolving the necessary adaptation and mitigation strategies.

• Capacity-building is required to enable NHMSs in the West African sub-region play the expected role of providing meteorological products and services for climate change adaptation and mitigation.


Thank You for Listening

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