They include soil, vegetation, air, and water. The tragedy of the commons refers to the way public resources are ruined by the isolated actions of individuals. Average daily calorie consumption is 3,300 in developed countries and 2,100 in developing countries. Averages must be adjusted according to age, gender, body size, and region of the world. Hunger in the Third World can be attributed to poor tropical soils, frequency of droughts, the impact of storms, and so on.
Hunger is overwhelmingly a problem attributed to human endeavor, however.
Africa is the only region where per capita food resources are actually declining steadily. The pace of Third World urbanization has contributed heavily to the food problem. Other human factors include maldistribution of the food resources, civil unrest, government policy and debt. Environmental decline, such as overuse of land and deforestation have lowered the agricultural productivity of the land. Expanding cultivated areas and raising productivity of existing cropland are two methods of increasing food production.