Geoscience Reference
In-Depth Information
an adverse effect on agricultural productivity. Furthermore, the
impact of climate change also poses a serious threat to food
security and needs to be much better understood. According to a
study, wheat yields in recent years marginally decreased in India,
France and China compared with what they probably would have
been without rising temperatures. Researchers have also claimed
that corn yields were off a few percentage points in some of the
countries from what would have been expected normally. Most
of the mechanisms and two-way interactions between agriculture
and climate are known, even though they are not always well
understood. It is evident that the relationship between climate
change and agriculture is still very much a matter of conjecture
with many uncertainties (Rosenzweig and Hillel, 1993).
5.2
Impact of climate change on crop production
Climate change has adversely affected global agriculture in
terms of productivity, economy and food security. Crop pro-
ductivity is vulnerable to decreases or increases in precipita-
tion. Small changes in temperature and rainfall could have
significant effects on the quality of cereals, fibre and bever-
age crops, fruits and some aromatic and medicinal plants with
resultant implications on their prices and trade. Agricultural
trade has risen, and is expected to increase further because of
instability in production quality and quantity due to climate
change impacts. Furthermore, not only will climate potentially
decrease the amount of land available for agricultural pro-
duction but there will also be an increase in competition for
resources with other developmental needs, such as infrastruc-
ture. Climate change will, undeniably, lead to more pressure on
an already-volatile economy. Agriculture affects all livelihoods,
occupying approximately 40% of the land globally, consuming
70% of the global water resources and affecting biodiversity
at all scales; from genetic to the ecosystem. An analysis 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. Global warming in the short term is likely to favour
agricultural production in temperate regions (largely northern
Europe, parts of North America) and negatively impact tropical
crop production (South Asia, Africa). According to Rosenzweig
and Liverman (1992), the regions differ significantly, both in
the biophysical characteristics of their climate and soil and in
the vulnerability of their agricultural systems. Tropical areas
