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the current wastage of what we eat, similar improvements in efficiency could happen
with global food.
However, if this does happen then Western consumers would have to accept
changes. To take just three examples, first, food miles would need to be reduced
dramatically to free agri-energy to improve productivity elsewhere, as well as to
reduce transition times during which spoiling can take place. This last would mean a
return to the seasonal availability of many foods and a reduction in year-round food
choice (although not choice across the year). A second possibility might be a change
in animal protein and fat consumption, which through much of the 20th century grew
ahead of population and which arguably is one of the factors behind obesity-related
health impacts that now dominate the health agendas of a number of developed
nations. Finally, there would need to be an increase in (sustainable) agricultural
intensity. This rise in production per unit area (productivity) in turn means a decrease
in biological resources available to wildlife within that agricultural area. There would
be biodiversity implications both within and outside of these agricultural areas (see
the discussion on agriculture, biodiversity and landscape in section 7.1.5).
Whereas improvements in food-supply efficiency may be a note of hope for our
species, if we are to avoid increasing starvation then humanity must feed itself
differently 30 years from now compared to today, and probably as differently as it
was fed 50 years ago. However, even with this it is hard to see pressures on natural
systems decline; indeed, it is almost inevitable that such pressures will increase.
Either way, greater resource management worldwide will be required.
The above summary does not emphasise the climate change factors. So, what are
the food-security implications of global warming? We have already seen that past
climate change has had a detrimental impact on civilisations, such as with the Incas
in the New World and the people affected by the Little Ice Age in the Old World.
It is therefore difficult to see why future climate change should not have impacts on
future food supply. With past change agricultural belts moved and the problems arose
because some civilisations did not move with them and exploit new areas. The same
problem is likely to affect future climate-related changes in agricultural production.
The big difficulty is that the present and future are far more crowded than the past.
There are increasingly limited options for opening up land that does not already have
a claim on it. A complicating matter is that a significant proportion of the human
population is concentrated along land-mass coastlines, some of which will be under
threat from climate-induced sea-level rise compounded by occasional intense run-off
from the land.
Climate-food models of future global agricultural production vary. Much depends
on both which model is used and the agricultural products that will be grown. This is
in part because, as with climate models, their resolution is too coarse. Also, because
climate and agriculture are so closely related, while climate models are not (yet)
sufficiently sophisticated for precision use in regional and local planning, so climate-
food models cannot be used for regional and local agricultural planning. Finally, it all
depends on what is actually being modelled. A model based on a region's biological
productivity and future climate will give different results to a model based on current
agricultural output because this last will not take into account how cultivated crops
and agricultural practices will alter with climate change.
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