Climate change impacts on agriculture have been identified as potentially the
most serious in terms of numbers of people affected and the severity of impacts on
those least able to cope. Moreover, agriculture is identified as particularly vulnerable and particularly critical in terms of global impacts. Given that impacts are
already occurring, and that expected future impacts have economic costs in the
present day, adaptation is clearly necessary and inevitable. New challenges are
emerging in terms of how to interpret the impacts of warming, how farming
systems adapt or are adapted to these changes, and how near-term emissions
mitigation requirements can take place in ways that are consistent with longer term
adaptation plants (Wreford et al. 2010).
Climate factors constitute some of the main constraints on crop and livestock
production and till recently have been assumed as exogenous and unchanging.
While farming has a history of responding to changing conditions, whether they
are economic, social, political, or climate-related, the potential increase in frequency and intensity of extreme climatic events, and other challenges posed by
climate change, now gives rise to a need to reappraise the adaptive capacity of
agricultural systems (Wreford et al. 2010).
Climate change may affect agriculture and food security by altering the spatial
and temporal distribution of rainfall, and the availability of water, land, capital,
biodiversity, and terrestrial resources (Hanjra and Qureshi 2010). The major
climate factors contributing to these responses include increasing atmospheric
carbon dioxide, rising temperature, and increasing extreme events, especially
droughts and floods (Rosenzweig 2007). Climate change may influence the future
occurrence of drought. Drought can have far-reaching consequences for agriculture, ecosystems, water availability, and society. Drought impacts can include
water scarcity, crop failure, wildfires, and famines (Taylor et al. 2013). Moreover,
observations have shown an increase in the severity and duration of droughts over
larger areas since the 1970s (Parry 2007). Modeling by IIASA Fischer et al.
(2007a) shows that future socioeconomic development and climate change may
impact on regional and global irrigation requirements and thus on agricultural
water withdrawals. Net irrigation requirements may increase by 45 % by 2080.
Even with improvements in irrigation efficiency, gross water withdrawals may
increase by 20 %. Global irrigation requirements with climate change will increase
by 20 % above the reference base case scenario. The simulation shows that the
global impacts of climate change on irrigation water requirements could be as
large as the projected increase in irrigation due to socioeconomic development
(Fischer et al. 2007a; Hanjra and Qureshi 2010).
Climate change could impact on rainfall and runoff and the availability of water
for irrigation in many regions and countries in the world. A decline in rainfall
along with an increase in temperature will increase crop water requirement due to
high evapotranspiration while less rainfall will increase crop net irrigation water
requirements. As a result, the already existing water scarcity problem will exacerbate in many regions and countries, and affect food production (Hanjra and
Qureshi 2010).
20
L. Garcia-Mier et al.
most serious in terms of numbers of people affected and the severity of impacts on
those least able to cope. Moreover, agriculture is identified as particularly vulnerable and particularly critical in terms of global impacts. Given that impacts are
already occurring, and that expected future impacts have economic costs in the
present day, adaptation is clearly necessary and inevitable. New challenges are
emerging in terms of how to interpret the impacts of warming, how farming
systems adapt or are adapted to these changes, and how near-term emissions
mitigation requirements can take place in ways that are consistent with longer term
adaptation plants (Wreford et al. 2010).
Climate factors constitute some of the main constraints on crop and livestock
production and till recently have been assumed as exogenous and unchanging.
While farming has a history of responding to changing conditions, whether they
are economic, social, political, or climate-related, the potential increase in frequency and intensity of extreme climatic events, and other challenges posed by
climate change, now gives rise to a need to reappraise the adaptive capacity of
agricultural systems (Wreford et al. 2010).
Climate change may affect agriculture and food security by altering the spatial
and temporal distribution of rainfall, and the availability of water, land, capital,
biodiversity, and terrestrial resources (Hanjra and Qureshi 2010). The major
climate factors contributing to these responses include increasing atmospheric
carbon dioxide, rising temperature, and increasing extreme events, especially
droughts and floods (Rosenzweig 2007). Climate change may influence the future
occurrence of drought. Drought can have far-reaching consequences for agriculture, ecosystems, water availability, and society. Drought impacts can include
water scarcity, crop failure, wildfires, and famines (Taylor et al. 2013). Moreover,
observations have shown an increase in the severity and duration of droughts over
larger areas since the 1970s (Parry 2007). Modeling by IIASA Fischer et al.
(2007a) shows that future socioeconomic development and climate change may
impact on regional and global irrigation requirements and thus on agricultural
water withdrawals. Net irrigation requirements may increase by 45 % by 2080.
Even with improvements in irrigation efficiency, gross water withdrawals may
increase by 20 %. Global irrigation requirements with climate change will increase
by 20 % above the reference base case scenario. The simulation shows that the
global impacts of climate change on irrigation water requirements could be as
large as the projected increase in irrigation due to socioeconomic development
(Fischer et al. 2007a; Hanjra and Qureshi 2010).
Climate change could impact on rainfall and runoff and the availability of water
for irrigation in many regions and countries in the world. A decline in rainfall
along with an increase in temperature will increase crop water requirement due to
high evapotranspiration while less rainfall will increase crop net irrigation water
requirements. As a result, the already existing water scarcity problem will exacerbate in many regions and countries, and affect food production (Hanjra and
Qureshi 2010).
20
L. Garcia-Mier et al.