CHAPTER 1
Humans and the Environment

CHAPTER OUTLINE

• 1.1 Human Impact on the Environment
• 1.2 Earth's Environments
• 1.3 Point Source and Non-Point Source Pollution
• 1.4 Pollution Affects Everything
• 1.5 What Can I Do About It?

Words you should know:

• Cryptocurrency - A digital or virtual money or asset that is built into a blockchain verification system. Mining of cryptocurrency is environmentally costly.
• Ecology - The branch of biology covering the interrelations of organisms and their relations to their surroundings.
• Environment - The interrelations of the chemical, biological, and physical natural world on a global or local level.
• Point source pollution - A single source of pollution that can be identified.
• Non-point source pollution - Pollution for which the source is so diffuse or distributed that it cannot be absolutely identified.
• Rachel Carson - The pioneer and most impactful person on the American environmental movement.

1.1 Human Impact on the Environment

Aside from a possible major war or very deadly pandemic, the greatest challenge humans are facing and will face for the foreseeable future center around pollution of the natural environment. Climate change as a function of human impact has taken center stage over the past few decades. US Vice President Al Gore and, more recently, Swedish student activist Greta Thunberg have become media sensations by bringing climate change to public attention. Society has even made an attempt to address it with hybrid and electric cars, solar panels, and wind farms. However, climate change is only one small aspect of the horrific problems plaguing the natural environment. Dead zones in the oceans from overuse of fertilizers, loss of pollinators from overuse of pesticides and habitat destruction, invasive species destroying native species and resulting massive extinctions are some of the less prominent but just as deadly issues. The new environmental spokespeople are helping to bring attention to some of these issues but all pale in comparison to the original and true environmental champion in America and indeed the world, Rachel Carson. She has been called the "mother of the American environmental movement" but this title does not nearly reflect the magnitude of her impact. During a time when few gave more than a fleeting thought to the natural environment, Rachel Carson brought her serious concerns to the highest level of the government and to the attention of the general public both in the United States and internationally. Her work started the entire study of the environment. She is a true hero.

Humans are notoriously damaging to the natural environment. Even in primitive cultures, groups of humans would cut down trees, make fires, move and break rocks, leave excessive waste, and strip areas of game and vegetation. It took several decades of natural processes for the areas to recover. Once humans established permanent settlements, the environmental damage became very localized but much more intense. The permanent structures, agriculture, and concentrated waste completely disrupted the natural environment and would take centuries to recover once abandoned. The first serious chemical pollution coincided with the Bronze Age and Iron Age which added mining, smelting, and forging of metals. These caused poisoning of air, soil, and water, and death of plants and animals in localized areas.

As civilization advanced, the building of stone structures on ever grander scales led to even greater environmental disruption. Settlements grew ever larger into cities, requiring larger agricultural efforts to support them. Forests were removed to support the production of food. Cities and structures built thousands of years ago still scar the landscape even if they are abandoned. Several inventions occurred over the centuries that accelerated the environmental damage. Gunpowder and arms that utilize it was a major change in environmental damage in addition to the humans killed by them. Paints, dyes, glass, burning of coal, and other chemical developments furthered this damage.

The Industrial Revolution brought a drastic change to the level of environmental impact. The first major pollutant was from mining and use of coal. It produces soot from burning but also from mining and storage. Coal powered the Industrial Revolution and it was spread widely by trains. In addition to dust, the impurities such as sulfur, mercury and other heavy metals, and coal caused widespread soil pollution by emissions and dumping of waste. Dumping dangerous and unsightly waste and emissions was the norm for the Industrial Revolution. As more dangerous contaminants were developed, the pollution intensified and increased. It was not until the environmental movement of the 1950s through 1970s that these practices were even slightly controlled.

Concurrent with the advancement of technology and largely as a result, the human population ballooned. The world population increased slowly from less than one half billion in 1000 AD to 1 billion in 1800. The accelerated growth began soon after and the population reached 2 billion by 1930 (Figure 1.1). In 1950, the acceleration of world population became exceptional, growing from about 2.5 billion to 7.8 billion over the next 70?years. This is far more than the Earth can handle and most environmental systems, both chemical and biological, are being overwhelmed. So many people are contributing to pollution problems that they will be difficult to control, if they are controllable at all. It will take a cooperative effort to keep the run-away overuse of resources and disruption of the environment not to destroy the human race and the planet.

FIGURE 1.1 Human population growth curve from 1800 to 2020 with projected possible growth to 2100

Source: Data from United Nations.

Pollution has now caused irreparable damage to the Earth for the foreseeable future. The result of human impact is that the Earth is experiencing what is widely believed to be the sixth major mass extinction event in the past 500 million years. It is estimated that more than 25% of all the known species will go extinct by 2050. It is not only the environment that is impacted by pollution but groups of humans are chosen to be more impacted than others based on economic status, whether they are in a developed country or not, and on race and ethnicity. This inequality has evolved into the field of environmental justice.

CASE STUDY 1.1 Rachel Carson (1907-1964)

Mother of the Environmental Movement

Rachel Carson is regarded as the mother of the American environmental movement (Figure 1.2). It was through her efforts that the first banning of pesticides and especially DDT occurred. Her work also led to the formation of the US Environmental Protection Agency. It is impressive that such a private, unassuming woman could influence such a major movement. Carson captured the interest of the American public and the top levels of government despite the efforts of major chemical companies to suppress her work and to professionally and personally discredit her. She testified before the US Congress about the dangers of pesticides. President Kennedy read her book Silent Spring, and as a result, he ordered an investigation of the pesticides that Carson identified as dangerous. They would be banned less than a decade later.

FIGURE 1.2 Portrait of Rachel Carson.

Source: Courtesy Everett Collection / Everett Collection / Adobe Stock.

Rachel Carson was born on 27 May 1907, in Springdale, Pennsylvania. She grew up on a small farm, where she developed her love of nature. In 1925, she enrolled in the Pennsylvania College for Women, which later became Chatham College. She began her studies as an English major but soon changed to biology and graduated magna cum laude in 1929 with a bachelor's degree. Carson received a scholarship to continue her education at Johns Hopkins University where she earned a master's degree in zoology in 1932. Her thesis was "The Development of the Pronephros during the Embryonic and Early Larval Life of the Catfish." She then taught zoology at the University of Maryland and conducted research at the Woods Hole Oceanographic Institution, Massachusetts during the summers.

Rachel Carson began a part-time position at the US Bureau of Fisheries in 1935, writing science scripts for the radio show Romance Under the Waters. She also wrote articles on natural history for the Baltimore Sun. Her part-time position transitioned in 1936 into a full-time position as junior aquatic biologist. Carson was the first woman in the United States to take and pass the civil service exam. She rose through the ranks of the US Fish and Wildlife Service, the succeeding division, over the next 15?years, ultimately becoming the Chief Editor of its publications. Rachel Carson also wrote several books that were successful enough to allow her to retire in 1952 at age 45. She built a cottage on the Sheepscot River near West Southport, Maine, and also kept a residence in Silver Spring, Maryland. In retirement, she completely devoted herself to writing.

Rachel Carson's life included extensive personal tragedy. In...