NATIONAL ASSEMBLY
WRITTEN REPLY
QUESTION 2063
DATE OF PUBLICATION: MONDAY 02 NOVEMBER 2009 [IQP No 26 -2009]
FIRST SESSION, FOURTH PARLIAMENT
Question 2063 for Written Reply: National Assembly, Dr LL Bosman (DA) to
ask the Minister of Agriculture, Forestry and Fisheries:
Whether she has been informed of the effect of climate change on (a) food
security, (b) the availability of water for irrigation and (c)(i) small-
scale farms and (ii) farms on marginal lands; if not, what is the position
in this regards; if this is so, what are the relevant details. NW2717E
REPLY
YES
a) Effects of climate change on food security
Climate change has a profound, unavoidable effect on food security as
increasing temperatures and shifting rain patterns reduce production.
Changing weather patterns or extreme weather events, such as floods or
droughts, have negative consequences for agricultural production.
Loss of arable land also impacts on food security. This could be due to
declining ground water levels or rising sea levels.
Climate change also leads to outbreaks of pests and diseases that further
weaken food systems. It induces outbreaks of pests such as the desert
locust. In the case of such an outbreak, locusts are capable of
destroying crops.
Fish stocks are also declining not only because of over-fishing but
because of declining water levels due to evaporation as a result of
rising temperatures.
b) Effects of climate change on the availability of water for irrigation
According to scientific reports, climate change is expected to alter
hydrological systems and water resources and reduce the availability of
water.
Rising temperatures and increasing variability of rainfall will generally
affect surface waters, increasing drought in some regions and causing
floods in others as well as influencing ground water recharge. There is
likely to be a general decrease of 5 - 10% of present rainfall with
longer dry spells in the interior and north-eastern areas of the country
coupled with more frequent and severe flood events. The probable effect
is greater evapo-transpiration and more stress on arid and marginal
zones.
c) (i) (ii) Effects of climate change on small scale farms and on farms on
marginal lands
Climate variables of temperature and precipitation are very relevant for
agricultural activities in South Africa and more so for dryland farming,
especially with respect to precipitation. Irrigated farms are cushioned
against adverse climate effects by having a substitute for rainwater.
Climate impacts were also found to have, to a large extent, a non-linear
relationship with net revenue. That is, increases in temperature and
precipitation will be beneficial to crop farming but beyond a certain limit
the impacts will be negative.
Based on the study conducted by the Centre for Environmental Economics and
Policy in Africa (CEEPA), University of Pretoria to assess the economic
impact of the expected changes in the climate on crop farming in the
country, the results suggest that net revenues for small livestock farms
increase with warming by 25 to 58 percent. A cross-sectional approach
(Ricardian) was used to measure the relationship between net revenue from
growing crops and climate in South Africa. The net revenues of large
livestock owners, however, are expected to fall except in a very dry
scenario. In general, small farms can more easily substitute animals that
are heat-tolerant, whereas large farms are more dependent on species, such
as cattle, that are less heat tolerant. Wetter scenarios imply a shift from
grasslands to forests, an increase in harmful disease vectors, and a shift
from livestock to crops.
Overall, the livestock sector in Africa loses from climate change, because
most animals are raised on large farms. While livestock earnings for small
farmers increase with warming, these gains are generally smaller than the
losses they face from crops. Still, the analysis suggests that under
certain future climate change scenarios livestock may become more
attractive than crops in many regions in Africa.