Background Image
Previous Page  62 / 104 Next Page
Information
Show Menu
Previous Page 62 / 104 Next Page
Page Background

62

As defined by the FAO, food security exists when all peo-

ple, at all times, have physical and economic access to

sufficient, safe and nutritious food to meet their dietary

needs and food preferences for an active and healthy

life. Future food security depends on developments in

both supply and demand, but projections for these vari-

ables are cursed with uncertainty. On the demand side,

population and economic growth are particularly sub-

ject to a high degree of uncertainty. Key uncertainties for

future supply have to go with agricultural productivity

and energy markets. In addition, developments are con-

tingent on new policies being put in place.

More specific causes of uncertainty in predicting future

trends are:

Climate change:

While mean temperature changes

are quite well modelled, rainfall changes and extreme

weather events are much less so, particularly at small-

er scales, neither are extreme weather conditions pre-

dictable today.

Energy supply:

If peak oil supply is reached within the

period under consideration, this will have major conse-

quences for the economics of virtually all aspects of food

production as well as on likely demands for biofuels.

Technological advances in food production

, such

as by the use of genetically modified crops may also

influence yield projections.

Availability of freshwater

(linked with climate

change and with technology).

Human behaviour:

Food preferences, ability to

adapt to changing conditions for food supply, com-

mitment to more equitable distribution of resourc-

es or increased tendency to defend local resource

base. (Economic factors as major proximate driv-

er of food production decisions: supply/demand

curves, input costs, extent of exposure to interna-

tional markets, government policy as expressed in

subsidies, tariffs, etc).

Impacts of pests and diseases

(including alien in-

vasive species) on food supply.

Actual versus predicted population growth.

Major disease outbreaks in humans.

Other catastrophic events

(war, major earthquakes,

volcanic events, etc).

The future impact of some of these is so unpredictable

that it is difficult to see how they can realistically be

incorporated into any quantitative models, other than

through including some essentially arbitrary tolerance

limits in calculating necessary food supplies.

Overall, no fully integrated model currently exists that

assesses agriculture in a holistic way. Current models

and scenarios focus on one or very few of these areas,

e.g., land use change (IMAGE model), global climate

models (e.g., UK Met office model), or are add-ons to

these models (e.g., GLOBIO biodiversity model) with

feedbacks and interconnections not fully integrated.

Uncertainties in future scenarios