The human ecology of climate change - Climate Change: Biological and Human Aspects - page 428

However, more significant annual temperature increases of 2.5 ◦ C or more could
prompt global food prices to rise. Again, the IPCC note that the greatest impacts will
be on the poorer farmers and consumers.
So why would increases in annual temperatures of upwards of 2.5 ◦ C have a net
detrimental effect? After all, a warmer, carbon dioxide-rich planet should mean that
there are some (new) places that will favour agriculture even if some other places
become unsuitable. The concern is that higher temperatures shorten the life cycle
of many cereals, hastening senescence and so reducing the length of the growing
season. The world's staple cereal crops tend to tolerate narrow temperature ranges,
which, if exceeded during the flowering stages, can damage production of fertile seeds
and reduce yields. Given that global warming is to increase the number of extreme
weather events, crop yield is likely to be impaired. This would also be compounded by
increases in ozone in the troposphere (which is low down in the atmosphere; Porter,
2005). This is likely to be more of a factor in parts of the globe where there are fewer
effective controls on air pollution, such as Asia.
Add climate change concerns to those of global demographics and some feel that
we might hit a period of 'peak food' just as there is thought to be a time when there
will be 'peak oil' consumption.
Given the almost certain demographic pressures anticipated for the rest of this
century, agricultural research needs to become a priority and this needs to be related to
high-resolution climate models that include the biological dimensions (which they are
now beginning to do). This is worth stressing because many developed nations have
been markedly reducing their investment in whole-organism agricultural research due
to past successes - reflected in the agricultural productivity (production per unit area)
rises - and past European and American food surpluses. Consequently a number of
governments have felt that with past success achieved there is little new challenge
on the horizon. In the UK governmental investment in policy-driven agricultural
research from the department responsible for farming and fisheries has declined in
real terms year on year since the mid-1980s to the present (2006/7).
Internationally, one fairly recent initiative to help co-ordinate research into food
security and environmental change was the Global Environmental Change and Food
Systems (or GECAFS) project. GECAFS was established in 2001 with formal part-
nerships with the UN FAO and WMO. It ran for a decade and a number of its outputs
were published in Food Security and Global Environmental Change in 2010, edited
by John Ingram, Polly Ericksen and Diana Liverman.
Then there are broader policy concerns beyond those of science research: policies
that enable us to reduce the speed of climate change and its extent, and adapt to likely
impacts, will help our global society to cope with the warming world of the 21st
century.
Finally, to bring sections 7.2 and 7.3 together, it is worth remembering that it is the
poor who will be detrimentally affected by climate change: both the poor in wealthy
nations and a greater proportion of the populations of less-wealthy nations. Yet it
has been the wealthy countries that have over the years added the most greenhouse
gas to the atmosphere. Figure 7.14 spatially compares national greenhouse emis-
sions with nations' incidence of four climate-sensitive diseases. It can be seen that
developed nations are those responsible for most emissions whereas less-developed
southern nations are likely to bear the brunt of changes in these diseases (with the