A global assessment of the potential impact of climate change on world food supply suggests that doubling of the atmospheric carbon dioxide concentration will lead to only a small decrease in global crop production. But developing countries are likely to bear the brunt of the problem, and simulations of the effect of adaptive measures by farmers imply that these will do little to reduce the disparity between developed and developing countries[1].
Some claim that overpopulation is the major cause of environmental degradation, whether it be neighborhoods or Cul de sac, all contribute to the over use of resources towards the environment. While populations no doubt are large in many countries, and demands on resources are obviously large, it is only one of many other causes and some of those other issues such as over-consumption based, unsustainable development may have an even larger impact. Some country's suffer more then the rest, Country's who don't cause any harm to the environment suffer the most because of their locations.
It seems obvious that any significant change in climate on a global scale should impact local agriculture, and therefore affect the world's food supply. Considerable study has gone into questions of just how farming might be affected in different regions, and by how much; and whether the net result may be harmful or beneficial, and to whom. Several uncertainties limit the accuracy of current projections. One relates to the degree of temperature increase and its geographic distribution. Another pertains to the concomitant changes likely to occur in the precipitation patterns that determine the water supply to crops, and to the evaporation demand imposed on crops by the warmer climate. There is a further uncertainty regarding the physiological response of crops to enriched carbon dioxide in the atmosphere. The problem of predicting the future course of agriculture in a changing world is compounded by the fundamental complexity of natural agricultural systems, and of the socioeconomic systems governing world food supply and demand. What happens to the agricultural economy in a given region, or country, or county, will depend on the interplay of the set of dynamic factors specific to each area. Scientific studies, typically based on computer models, have for some time examined the effects of postulated climate and atmospheric carbon dioxide changes on specific agroecosystems--a now common term that defines the interactive unit made up of a crop community, such as a field of wheat or corn, and its biophysical environment. We have more recently gone a step farther by developing methods to study these systems in more integrated regional and global contexts. To address any of them more clearly we must first define the main interactions that link a chain of processes together: food is derived from crops (or from animals that consume crops); crops in turn grow in fields, which exist in farms, which are components of farming communities, which are sectors in nation states, and which ultimately take part in the international food trade system. Understanding the potential impacts of global environmental change on this sequence of interlocking elements is a first step in modeling what will happen when any one of them is changed as a result of possible global warming, and a prerequisite for defining appropriate societal responses.
In this summary we look first at the possible biophysical responses of ecosystems to the specific environmental changes that are anticipated as a result of the buildup of global greenhouse gases, and then at the range of adaptive actions that might be taken to ameliorate their effects. In subsequent sections we draw on our own and other modeling studies to show examples of regional and global assessments that have so far been made, including discussions of the effects of uncertainty, thresholds, and surprises, and the possible consequences of global warming on agricultural sustainability and food security. Finally we give our own views on two potentially misleading notions regarding climate change and agriculture.[2]
[1]http://www.nature.com/nature/journal/v367/n6459/abs/367133a0.html
[2]http://www.gcrio.org/CONSEQUENCES/summer95/agriculture.html
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