Impacts of Climate Change on Agriculture - Climate Resilient Agriculture for Ensuring Food Security - page 42

4

Impacts of Climate Change
on Agriculture

Abstract
Climate change and agriculture are interrelated processes, both of which take
place on a global scale. Global warming is projected to have signifi cant
impacts on conditions affecting agriculture, including temperature, carbon
dioxide, precipitation, sea-level rise, increasing ocean acidifi cation, UV-B
radiation, extreme weather events, glacier retreat and disappearance, ENSO
effects on agriculture, and the interaction of these elements. These conditions
determine the carrying capacity of the biosphere to produce enough food for
the human population and domesticated animals. The overall effect of climate
change on agriculture will depend on the balance of these effects. Assessment
of the effects of global climate changes on agriculture might help to properly
anticipate and adapt farming to maximize agricultural production.
The effects of carbon dioxide (CO 2 ) enrichment, without associated
changes in climate, would probably be benefi cial for agriculture. However,
more severe warming, fl oods, and drought may reduce yields. Higher
temperatures, however, could increase the rate of microbial decomposition
of organic matter, adversely affecting soil fertility in the long run. An anal-
ysis of the biophysical impact of climate changes associated with global
warming shows that higher temperatures generally hasten plant maturity
in annual species, thus shortening the growth stages of crop plants. Also,
studies analyzing the effects on pests and diseases suggest that tempera-
ture increases may extend the geographic range of some insect pests
currently limited by temperature. The effects of increased ultraviolet-B
(UV-B) radiation reduce yield in certain agricultural crops. Livestock may
be at risk, both directly from heat stress and indirectly from reduced
quality of their food supply. Fisheries will be affected by changes in water
temperature that shift species ranges, make waters more hospitable to
invasive species, and change life cycle timing.

Keywords
Temperature • Carbon dioxide enrichment • Precipitation • Sea-level rise
• Increasing ocean acidifi cation • UV-B radiation • Extreme weather events
• Glacier retreat and disappearance • ENSO effects on agriculture