Agriculture Reference
In-Depth Information
It is likely that there will also be important
effects on nutrition as a result of climate change.
To date, studies mostly focus on cereals. There is
a need to better capture all the nutritional conse-
quences of the effects of climate change on live-
stock and on vegetables and wild foods, all of
which have an important role in balanced diets
and which are at risk (HLPE 2012 ; Bharucha and
Pretty 2010 ).
In the last decade, an overwhelming consensus
has emerged among scientists that the world has
entered an era of rapid global climate change, much
of which is attributable to greenhouse gas (GHG)
emissions from human activity. Rapid global cli-
mate change is expected to impact agriculture by
causing shifts in temperature, precipitation, soil
quality, pest regimes, and seasonal growth patterns.
To cope with climate change that is likely to be
both rapid and unpredictable, agricultural systems
must be resilient and able to adapt to change.
Resilient agriculture systems are those that are
more likely to maintain economic, ecological, and
social benefi ts in the face of dramatic exogenous
changes such as climate change and price swings.
In the face of uncertainty, food production systems
should be established which are diverse and rela-
tively fl exible, with integration and coordination of
livestock and crop production.
The changes in agricultural production in all
regions (globally) are consequence of changes in
some physical key factors that are expected to be
modifi ed with climate change. This includes
changes in sea level, CO 2 , atmospheric O 3 ,
extreme events, precipitation intensity, tempera-
ture, heat stress, etc. Soil erosion is a factor that is
directly affected by climate conditions and has
major consequences for agricultural productivity
(Table 4.2 ).
Table 4.2 Climate change and related factors relevant to agricultural production at the global scale (Iglesias et al.
2009 )
Climate and related
physical factors
Potential impacts on agricultural
production
Confi dence level of
the potential impact
Expected direction of change
Atmospheric CO 2
Increase from 360 ppm to
450-600 ppm (2005 levels now
at 379 ppm)
Good for crops: increased
photosynthesis; reduced water use.
Increased biomass production and
increased potential effi ciency of
physiological water use in crops
and weeds. Modifi ed hydrologic
balance of soils due to C/N ratio
modifi cation. Changed weed
ecology with potential for increased
weed competition with crops
Medium
Agroecosystems modifi cation
High
High N cycle modifi cation
High
Lower yield increase than expected
Low
Atmospheric O 3
Increase
Crop yield decrease
Low
Sea level
Rise by 10-15 cm. Increased in
south and offset in north by
natural subsistence/rebound
Loss of land, coastal erosion,
fl ooding. Sea-level intrusion in
coastal agricultural areas and
salinization of groundwater supply
High
Extreme events
Poorly known, but signifi cantly
increased temporal and spatial
variability expected. Increased
frequency of fl oods and droughts
Crop failure
High
Yield decrease
Competition for water
Storminess
Increased wind speeds,
especially in north. More intense
rainfall events
Lodging, soil erosion, reduced
infi ltration of rainfall
Very low
(continued)
 
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