Critical Links: Population, Health, and the Environment

The impact of the world’s 6.3 billion people on the environment is unprecedented. Humans had a negligible effect on the environment 3000 years ago when fewer than 100 million people lived on Earth but by the early 21st century we have altered more than one-third of Earth’s ice-free surface and threatened the existence of many plant and animal species. These changes also pose threats to our well being. The burning of gas coal and oil for example is increasing concentrations of carbon dioxide in the atmosphere altering the global climate and affecting human health. The number of people is just one factor driving environmental change. Other demographic factors also cause change. Where people live and the rate of population growth increase the demand for natural resources such as water and fossil fuels adding pressure on environmental systems such as watersheds and rainforests. The relative proportions of children persons of working age and elderly within a population have repercussions for future population growth health risks and use of services such as public transportation. Other forces such as public policies technological developments and culture can ease or worsen the pressures that these demographic factors place on society and the environment. One example is the growth of cities throughout the world. This urban growth brings changes in lifestyles consumption patterns infrastructure development and waste production. (excerpt)