The human ecology of climate change - Climate Change: Biological and Human Aspects - page 424

which data were available to the 2004 FAO report's authors, weather-related causes
of hunger increased year on year, with drought listed as a cause in 60% of food emer-
gencies. Even where overall water availability is adequate, erratic rainfall and access
to water can cause both short-term food shortages and long-term food insecurity.
Floods are another major cause of food emergencies. Sharp seasonal differences in
water availability can also increase food insecurity. In India, for example, more than
70% of annual rainfall occurs during the 3 months of the monsoon, when most of it
floods out to sea.
Conversely, farmers who lack irrigation facilities must contend with water scarcity
throughout much of the year and the threat of crop failures when the monsoons
fail. Where water is scarce and the environment fragile, achieving food security may
depend on what has been called virtual water: foods imported from countries with an
abundance of water. It takes 1 m 3 of water to produce 1 kg of wheat. Extrapolating
from those numbers, the FAO calculated that to grow the amount of food imported by
Near-Eastern countries in 1994 would have required as much water as the total annual
flow of the Nile at Aswan. In such conditions it may make sense to import food and
use limited water resources for other purposes, including growing high-value crops
for export. As we have seen (Chapter 6), in a globally warmed world not only can
we expect extremes in precipitation (more evaporation of seas, more rain) but also
greater evaporation on land and through plant photorespiration. With global warming
water availability will become a key issue and, against a backdrop of an increasingly
populous planet, a driver of food insecurity.
The 2008 FAO The State of Food Insecurity report focused on the 2007-8 food
crisis discussed in section 7.4.1. The 2009 report noted that even before the food and
economic crises, hunger was on the rise and that the World Food Summit target of
reducing the number of undernourished people by half to no more than 420 million
by 2015 will not be reached if the trends that prevailed before those crises continue. It
also estimated that 1.02 billion people are undernourished worldwide. This represents
more hungry people than at any time since 1970 and a worsening of the unsatisfactory
trends that were present even before the 2008-9 financial crisis. It reported that this
financial crisis was now affecting the poor in poor nations as incomes were not rising
and global food market prices remained high: the food problems of 2009 were not
due to poor harvests. Conversely, the 2010 report was marginally more optimistic,
reporting that the number of undernourished had declined from the levels of the
previous 2 years but was still higher than before the 2007-8 food crisis.
The FAO's 2011 report summarised the food context of the two - food and
financial - crises, opining that prices are generally expected to rise because con-
tinued population and economic growth will put upward pressure on demand, as will
the anticipated increased use of biofuels (depending on biofuel policies and the price
of oil). On the supply side, if oil prices continue to rise, agricultural production costs
will increase, contributing to higher food prices. Natural resource constraints, espe-
cially climate change and the limited availability of productive land and water in some
regions, pose substantial challenges to producing food at affordable prices. On a more
positive note, there remains significant potential for raising crop productivity through
new technologies and improved extension, as well as for reducing losses in the sup-
ply chain. However, these gains will not materialize without increased investment.