Food Security under Global Change

Naturally, these climate changes have direct effects on agricultural production. It is anticipated that for moderate global average temperature increases (estimated between 1-3oC), there will be an overall increase in global food production. Additional temperature increases, however, would cause an o v erall fall in food production.

So who are likely to be the winners as the climate changes and who are likely to lose out? In very general terms, some regions at lower latitudes will become hotter and drier with a shortened growing season. Small scale and subsistence farmers will be at particular risk. The AR4 has also confidently predicted that by 2020, rain fed agricultural production will fall by 50% in many African countries. A number of arid and semi-arid areas may simply fall out of agricultural production. In contrast, other regions, in higher latitudes and including parts of Europe and the western USA, will become warmer and wetter with an extended growing season. This provides the potential of an increased level of production, though producers may need to adapt and change their agricultural techniques and the types of crops grown. The ability of a country to respond to this may well depend on its preparedness and wealth.

If predictions based on the current levels of global warming are realised, between 75 and 250 million people will be exposed to increased water stress due to climate change. By 2030, production from agriculture and forestry is projected to decline over much of southern and eastern Australia due to increased drought and fire. By 2050, freshwater availability will be decreased in Central, South, East and S E Asia. Coastal areas will be at increased risk of flooding from the sea or the river megadeltas.

Overall, this means that we can expect malnutrition levels to increase in some of the worlds most vulnerable populations. Additionally, we need to anticipate more droughts, heat-waves and floods. This article has focused on the impact of climate change upon food security through agricultural production effects alone. However, the impact of climate change on other sectors like human health through changes in infectious disease vectors will also impact food security but are difficult to quantify.