The Environmental Significances of Population Dynamics

Abstract

Population increase during the mid-twentieth century as mortality declines in many developing nations were not matched with reductions in fertility, resulting in unprecedented growth rates. Concern with environmental change has come to the forefront primarily since 1970, with discernible levels of environmental degradation fueling public concern with the scope of contemporary environmental transformations and the advent of satellite imagery aiding environmental research. Rapid population growth and global environmental change are two issues that have received important public attention over the past several decades. It has become increasingly clear that human populations have a powerful effect on the environment and become a global public policy issue. Yet the exact relationship between population dynamics and the environment is complex. This paper reviews the environmental significances of population dynamics, based on current knowledge of the relationships between population factors and various aspects of the natural environment. This research is important for several reasons. • Compared with human-induced environmental changes of centuries past, the geographic scope of contemporary human-induced change is much larger. The rate of change is also much faster. The Earth's surface air temperature has increased by between 0.3 degrees and 0.6 degrees. Scientists have discovered that human activities as land-use change and fossil fuel use appear linked o increased concentrations of several atmospheric gases which warm the Earth's atmosphere and surface temperature.' As a result, humans appear partially responsible for environmental changes at the global scale-large-scale changes that have taken place in less than 200 years. • Some human-induced environmental changes have irreversible consequences. Ii is estimated that nearly 12 percent of mammals and 11 percent of bird species are currently threatened with extinction. In fact, the currently confronted episode of biodiversity loss is greater than the orld has experienced for the past 65 million years. Although some human activities, such as conservation programs, aim to preserve or enhance biodiversity, human-induced habitat destruction remains the primary cause of species decline. • The effects of contemporary environmental changes on humans are also increasing in scope. Global estimates suggest there may be as many as 25 million ”environmental refugees” -individuals who have migrated because they can no longer secure a livelihood from the land because of deforestation, desertification, soil erosion, and other environmental problems. • Human population continues to grow. In the face of rapid, large-scale, human-induced environmental change, human numbers increase each year by approximately 80 million. Those areas with continuing high fertility and resulting population growth are typically those with the least environmental resilience and those facing the greatest resource constraints. Although Earth already faces severe air pollution, water contamination, and other environmental ills, more than 90 percent of future population growth is projected to take place in these areas. This paper discusses the relationship between population and natural environmental change, the forces that mediate this relationship, and how population dynamics specifically affect climate change and land-use change and like to outline both sides of the policy debate that have emerged-those who would limit fertility and population growth in the developing world and those who need reduced consumption in the developed world. I also like to call for policymakers to pay increased attention to the role of population and forsake the search for one-step solutions to environmental problems.