Assessing the impacts of climate variability and change on agricultural systems in Eastern Africa while enhancing the region’s capacity to undertake integrated assessment of vulnerabilities to future changes in climate
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Date
2015-02
Journal Title
Journal ISSN
Volume Title
Publisher
ICRISAT
Abstract
One
of the key messages emerging out of the recent IPCC reports is that the climate change is real,
happening and will continue to happen for the foreseeable future
,
irrespective of
what happens to future
greenhouse gas emissions
. The report also estimates wi
th high confidence that the negative impacts on
agriculture outweigh the positives which makes adaptation an urgent and pressing challenge. However,
adaptation planning requires accurate information about where, when and how the impacts are going to
be fel
t and who will be more vulnerable.
Among the regions, Africa is considered as more vulnerable due
to its high dependence on agriculture for subsistence, employment and income. In Eastern Africa,
agriculture accounts for 43% of GDP and contributes to more than 80% employment (Omano et al. 20
06).
Within Africa,
Eastern Africa is one of the most vulnerable regions due to its high dependence on
rain
-
fed
agriculture for subsistence, employment and income. The region
experiences high variability in rainfall
(Webster et al., 1999, Hastenrath et al.
, 2007)
which has a direct bearing on
the
performance of
agriculture. Generally the region experiences prolonged and highly destructive droughts covering large
areas at least once every decade and more
localized
events
even
more frequently.
The region reco
rded
severe droughts and/or famines in 1973
-
74, 1984
-
85, 1987, 1992
-
94, 1999
-
2000, 2005
-
2006 and more
recently in 2010
-
11. According to UNDP (2006), a single drought event in a 12
-
year period will lower GDP
by 7%
–
10% and increase poverty by 12%
–
14%. Extrem
e events, including floods and droughts, are
becoming increasingly frequent and severe (IPCC 2007). Based on
the
analysis of data from the
international Disaster Database (EM
-
DAT), Shongwe et al. (2009)
concluded that
there has been an
increase in the numb
er of reported disasters in the region, from an average of less than 3 events per year
in the 1980s to over 7 events per year in the 1990s and 10 events per year from 2000 to 2006. The negative
impacts of climate are not limited to the years with extreme c
limatic conditions. Even with normal rainfall,
the countries in the region do not produce enough food to meet their people’s needs. Left unmanaged,
these impacts can have far
-
reaching consequences on the local food security, economy, and poverty.
Over the
past few years,
climate research has contributed significantly to
increased
understanding
of how
the
climate
in
the region
is
var
ying
on inter
-
annual and decadal time scales and
on
how
the climate is
changing
in response to global warming and other factors
. The
impacts of this variability and changes in
climate on various sectors including agriculture have also received considerable attention
.
These studies
indicate that a
griculture, especially the one practiced under rainfed
conditions in moisture limiting
environments such as semi
-
arid tropics
,
is one of the most vulnerable sectors
since
these are relatively
warmer places and rainfall is the only source of water.
There is a rapidly growing literature on vulnerability
and adaptation to climatic variability
and change
,
but most of these
studies
are based on
assessments
made using
statistical and empirical models that fail to account
for
the
full range of complex interactions
and
their effects on agricultural systems
(Parry et al., 2004; Cline, 2007; Lobell e
t al., 2008).
Evidence
available to date
indicate
s
that w
ith 1°C of warming, roughly 65% of current maize growing areas in Africa
will experience yield losses (Lobell et al., 2011)
and the average
predicted production loss
es
by 2050 for
most crops are in t
he ra
n
ge of 10
-
25%
(Schlenker and Lobell, 2010)
.
For
developing and implementing
adaptation programs, more detailed information about
the impacts of
climate change on various components of the smallholder farming systems
such as which crops and
varieties
are more vulnerable and which management practices are unviable is
required
.
This requires
a
comprehensive
assessment using site and location specific climate and crop management information.
However, s
everal problems
constrain
such an assessment. Firstly,
downscaled local level climate change
projections
that are required to make such assessments are not readily available
.
While climate models
provide various scenarios with high levels of confidence at global and sub
-
regional level,
there are
challenges in
downscaling
them to
local level
(IPCC, 2007)
. Secondly,
lack of information on
the sensitivity
of smallholder
agricultural systems
to changes in climate
.
Though process based
crop simulation models
can serve as
important
tools to make
a
more realistic assessment of
impacts of climate variability and
change
on agricultural systems,
application of the same is limited to few location specific studies mainly
because of the intensive data requirements and practical limitations including capaci
ty to calibrate,
validate and perform detailed analyses.
Thirdly, there is scarcity of information on how the impacts of
climate change on the production and productivity
of agriculture
translate into economic impacts
including food security at household a
nd national levels.
This assessment is
aimed at developing more
accurate information on how the projected changes in
climate impact
the
productivity and profitability of agricultural systems that are widely adopted
by
smallholder farmers
in Eastern Africa
using
the
protocols and methods developed by
Agricultural Model
Intercomparision and Improvement Project (AgMIP)
(Rosenzweig et al., 2013)
.
One key aspect of this
assessment is the attention paid
to
captur
e
the
complexity and
diversity
that exists in the
s
mallholder
farm
ing systems
including
the different ways in which th
e system
is managed.
The study
is an
attempt to
make a
comprehensive assessment of climate
change on
crop
growth and performance
under conditions
that
interactions
as well as
related economic impacts
by
integrat
ing
state of the
art downscal
ed
climate
scenarios with crop and economic models.
Th
e assessment was
carried out
in contrasting
agro
-
ecological
zones
spread over the four major countries in eastern Africa
–
Ethiopia, Keny
a, Tanzania and Uganda. This
report
summarizes
the findings that include
trends and changes
in
the observed and downscaled climate
scenarios, quantified
information on
impacts of
these trends and changes
on performance of
maize
under
a range of
environment
al
and management
conditions,
implication
of
these
changes
in crop performance
on
in
come, poverty and food security of smallholder farmers
and potential adaptation strategies that can
assist smallholder farmers in
minimizing negative impacts
.
Description
Keywords
Climate change, economic impacts