To be healthy means to be free from injury or illness. For humans, and increasingly for other species, to be healthy refers to physical, mental, and emotional well-being. A disease is a condition or abnormal function that affects all or part of an organism’s health.
A variety of environmental changes can affect human health, including changes in the Earth’s climate and ecosystems:
- The availability of clean freshwater and nutritious food.
- Regional air quality.
- The presence of pollutants and waste.
- Interactions with other species that carry diseases or affect human health, including parasites and mosquito-borne illnesses.
- Regional temperatures (i.e., extreme heat and cold events).
Can you think of additional cause and effect relationships between human health and disease and other parts of the Earth system?
Visit the freshwater quality and availability, food availability and nutrition, air quality, and the displacement of human populations pages to learn more about how global changes affect the quality of human life.