Impacts of Climate Change on Agriculture - Climate Resilient Agriculture for Ensuring Food Security - page 43

Climate change has already signifi cantly
impacted agriculture (Lobell et al. 2011 ) and is
expected to further impact food production
directly and indirectly. Increase of mean temper-
ature, changes in rain patterns, increased variabil-
ity both in temperature and rain patterns, changes
in water availability, the frequency and intensity
of “extreme events,” sea-level rise and saliniza-
tion, and perturbations in ecosystems all will
have profound impacts on agriculture, forestry,
and fi sheries (Gornall et al. 2010 ). The extent of
these impacts will depend not only on the inten-
sity and timing (periodicity) of the changes but
also on their combination, which are more uncer-
tain, and on local conditions. Anticipating appro-
priately the impacts of climate change on
agriculture requires data, tools, and models at
the spatial scale of actual production areas. Since
the last IPCC report in 2007, some studies have
attempted to anticipate these impacts and pro-
vide projections at such a scale, enabling us to
have a more concrete vision of projected changes.
Climate change may lead to an increase in
both crop and livestock productivity in mid- to
high latitudes (IPCC 2007 ) and a decrease in
tropical and subtropical areas. Among the most
affected areas are economically vulnerable coun-
tries already food insecure and some important
food-exporting countries. This will induce sig-
nifi cant changes in trade, impacting prices and
the situation of net food-importing countries.
Consequently, climate change is expected to
increase the gap between developed and develop-
ing countries as a result of more severe impacts in
already vulnerable developing regions, exacer-
bated by their relatively lower technical and
economical capacity to respond to new threats
(Padgham 2009 ). Smallholders and pastoralists
will suffer complex and localized impacts (IPCC
2007 ). According to the International Food Policy
Research Institute (IFPRI), it will cause an
increase of between 8.5 and 10.3 % in the number
of malnourished children in all developing coun-
tries, relative to scenarios without climate change
(Nelson et al. 2010 ).
Crop production is increasingly vulnerable to
risks associated with new and evolving climatic
changes. These are variations in environmental

conditions that pose signifi cant challenges to
farmers, over and beyond those that are experi-
enced “normally.” The planet is facing more
extreme weather events, such as heavy precipita-
tion, higher coastal waters, geographic shifts in
storm and drought patterns, and warmer tempera-
tures (IPCC 2012 ).
Climate change is expected to cause substan-
tial crop reductions in South Africa (up to 30 %
by 2030 for maize production) and South Asia
(up to 10 % for staples, such as rice, and more
than 10 % for millet and maize) (Lobell et al.
2008 ). In mid- to high latitude, depending on the
crop, productivity may increase slightly with
increases in local mean temperatures of up to
1-3 °C. At lower latitudes, crop productivity will
decrease even with a relatively minor change in
temperature (IPCC 2007 ). Localized extreme
events and sudden pest and disease outbreaks
are already causing greater unpredictability in
production from season to season and year to
year and require rapid and adaptable management
responses (FAO-PAR 2011 ). Climate change will
have a signifi cant impact on crop production
(Table 4.1 ).

Table 4.1 Examples of projected climate change impacts
on crop production (IPCC 2007 ; FAO 2008 )
Event Potential impact

Cold periods
becoming warmer
and shorter; over most
land areas, days
and nights becoming
hotter (virtually
certain)

Increased yields in colder
environments; decreased yields
in warmer environments;
increased outbreaks of new
insect pests and pathogens;
potential impacts on crop
production

Heavy precipitation
events increasing in
frequency over most
areas (very likely)

Damage to crops; soil erosion;
inability to cultivate land
owing to water logging of soils

Drought-affected area
increases (likely)

Land degradation and soil
erosion; lower yields from
crop damage and failure; loss
of arable land

Intense tropical
cyclone activity
increases (likely)

Damage to crops

Extremely high sea
levels increase in
incidence (excludes
tsunamis) (likely)

Salinization of irrigation water,
estuaries, and fresh water
systems; loss of arable land