Geoscience Reference
In-Depth Information
5
o
+-----------~----------~~--------,
1960
1980
2000
2020
Year
Figure 6.3
Growth in annual wheat yield (%) with 1961-2010 shown as a 10-year
running average
Source: FAO, 2012
previous values by the early 2000s (
Figure 6.2
). This very positive outcome has
arisen through the introduction of improved crop varieties and through improved
overall management that has reduced production risk and price fluctuations.
However, over the past few years there has been a noticeable upswing in
the variability of crop production with this returning to levels experienced 20
years ago (
Figure 6.2
)
. This deterioration in the stability of crop production is
a response to several climate extremes - including droughts and heatwaves in
Australia, Russia, Europe and the USA - and it may well have impacted on the
recent food price spikes and food shortages in some parts of the world (FAO,
WFP and IFAD, 2011). These recent events mar what has otherwise been a
remarkable outcome from investment in enhanced crop genetics and agronomy,
leading to a multi-decadal period when both average production increased and
the variability of production decreased.
The area planted to crops across the globe showed steady increases through to
the mid 1980s when 725Mha were grown annually with this dropping to about
670Mha by year 2003 and then again increasing to about 700Mha currently
(FAO, 2012). In contrast, crop yields - the other key component of production
- have shown strong trends with year-on-year yield growth dropping from around
3 per cent in the 1960s to about 1.2 per cent now (
Figure 6.3
). Again, this is less
than the 1.7 per cent needed to meet expected future growth in food demand
(Beddington et al., 2012).
These simple global analyses demonstrate that there are already substantial
existing challenges to the capacity of cropping systems to meet food security
demands in terms of production, yields and their variability. Similar issues arise
for the livestock sector. Projected climate changes arising from greenhouse gas
