The U.S. Census Bureau estimates that the world’s population is over 7 billion and growing. It took only 50 years for the global population to double in size, according to the United Nations. As population growth accelerates, human demand for space and resources increases. This rapid growth in the human population has significant effects on the physical environment by generating pollution, influencing climate change and threatening species diversity.


Countless human activities result in the pollution of our land, air and water. As the human population increases, the garbage and waste we produce increases. Landfill space is dwindling and much of our garbage piles up in natural areas. According to the Smithsonian, ocean currents have trapped two massive patches of plastic garbage in the Pacific Ocean. Industrial and agricultural operations also increase to meet demand, which leads to an increase in the pollution these practices cause. For example, the manufacture of computers, cell phones and other IT products results in the discharge of heavy metals, such as lead, which threaten human health and the environment.

Climate Change

Industrial practices, including the combustion of fossil fuels for energy, release greenhouse gases into the atmosphere. As the population grows, more people need energy for shelter, food production and transportation. The U.S. Environmental Protection Agency estimates that industrial operations, transportation and electricity consumption account for more than 80 percent of the greenhouse gases emitted in the United States. Greenhouse gases, such as carbon dioxide, trap heat in the atmosphere causing climate change that displaces species and alters weather patterns.

Species Diversity

Humans compete with other animals for space, and human development often results in the destruction of wildlife habitat. According to the Center for Biological Diversity, the human population grows by 250,000 people every day; this rapid growth puts pressure on land, water and food resources and is causing the extinction of numerous species. Animal populations that were prolific 200 years ago, when the human population was only 1 billion people, have now disappeared. Woodland bison no longer roam West Virginia and Arizona’s herds of Merriam’s elk have vanished.

Water Shortage

In the past 100 years, human water use has been rising at a faster rate than population growth, according to the United Nations. With more people using even greater quantities of water across the planet, water scarcity is a growing concern. The U.N. estimates that more than 1 billion people do not have access to clean drinking water. Technically, there is enough fresh water on Earth to sustain 7 billion people, but that water is not distributed equally or accessibly. Some regions along the equator do not have the water resources to support local populations, and areas of Africa do not have the sanitation and distribution infrastructure to deliver the water resources that exist.