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GlossaryUnit 7: Agriculture // Section 10: Food for the Future
Although the world produces enough total calories to feed all of its inhabitants today, more than 800 million people are undernourished, mainly in Africa and Asia (footnote 20). Food insecurity can have many causes, including poverty, wars, and diseases such as HIV/AIDS. However, in some areas soils and water supplies are so degraded that agricultural systems cannot produce enough food to meet human needs.
As the human population climbs towards its estimated peak of 10 billion, the environmental impacts of feeding so many people will increase. But this challenge also offers an opportunity: by making agriculture increasingly sustainable, we can meet the goal of feeding the world's population while reducing associated environmental problems such as water pollution. Reorienting agricultural systems is a complex task because the technical challenges are intertwined with social and economic issues such as land tenure and availability of foreign aid for developing countries. The magnitude of future agricultural effects on the environment will be influenced by many factors, including:
- Actual demand for food. Food demand will increase with population growth and rising income, which increases consumers' preference for animal protein.
- Expansion of agricultural lands. Agriculture will move into increasingly marginal areas because Earth's most fertile zones are already under cultivation, and will compete with other land uses such as urbanization.
- Opportunities for increased yields. Likely technological innovations include systems that increase availability of water and fertilizer; improved pesticides and biocontrols such as IPM; better soil conservation and management of microbial communities; and new crops that deliver increased yields under wider ranges of conditions and need fewer inputs than current strains.
- Availability of water and chemical fertilizers. The prices of these inputs are strongly affected by energy costs and competition for fresh water with other human activities.
- Global climate change. Variable weather is a major challenge for farmers because optimizing for high yields becomes more difficult as the range of potential weather conditions that might occur in any season increases. In the coming decades, global climate change is predicted to alter temperature and precipitation patterns in ways that could modify major elements of Earth's climate system (for details, see Unit 12, "Earth's Changing Climate").