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HOW DO WE INTERACT WITH THE ENVIRONMENT? SCIENCE AND THE ENVIRONMENT

ENVIRONMENTAL SCIENCE Environmental science seeks to understand people and the environment influence each other. There are two major areas of concern: How do we use resources in the environment? How are we altering the environment? Note that this question does not necessarily imply we are knowingly changing our environment!

ENVIRONMENTAL SCIENCE

THE ENVIRONMENT AND US Humans have always had a substantial impact on the environment.

HUNTER-GATHERERS For the majority of human history, we were hunter- gatherers. Groups were small and often migratory.

THE AGRICULTURAL REVOLUTION Over time, humans learned to grow crops and domesticate various animals. We call these practices agriculture.

THE AGRICULTURAL REVOLUTION This development led to several important changes in human society. Human populations had enough resources to grow into large groups. Humans began to concentrate their numbers in smaller and smaller areas. Humans began to selectively breed both plants and animals. Humans also began to convert substantial patches of land into farmland.

THE INDUSTRIAL REVOLUTION Human society was powered by and dependent on manual power for about 2.5 million years. This changed with the development of alternate energy sources. Examples?

THE INDUSTRIAL REVOLUTION A large variety of more efficient energy sources – such as water, coal and oil – led to the development of industrial engines and machines.

THE INDUSTRIAL REVOLUTION The Industrial Revolution has had a huge hand in shaping modern human society. Humans began to develop factories and other centers of mass production. Less land and labor was needed to maintain human populations. The quality of transportation improved greatly. Even more food was available to support larger populations. Urban populations, in particular, began to grow. Quality of life also improved considerably, and the average human lifespan increased.

MODERN DEVELOPMENTS Both the agricultural and Industrial revolutions have allowed the human population to grow incredibly fast.

MODERN DEVELOPMENTS Earth itself functions as a closed system – resources on Earth are limited, and there is no efficient way to eliminate waste products.

MODERN DEVELOPMENTS Together, these developments mean that we as a species are placing tremendous pressure on the environment!

WHAT DO WE WORRY ABOUT? MAJOR AREAS OF CONCERN

RESOURCE DEPLETION A natural resource is any material or energy source we humans can use. Classified into two types: Renewable Non-renewable Depletion refers to using up a resource.

POLLUTION Like all other organisms, humans produce waste products. However, since the Industrial revolution, we are beginning to produce wastes faster than they can be disposed! Pollution is defined as an undesirable change to the air, water or soil. This change must adversely affect the health, survival or activity of one or more organisms (including humans!)

POLLUTION Biodegradable wastes These are those that can be broken down via natural processes. Food waste Human sewage Nondegradable wastes These are those that cannot be broken down via natural processes. Lead Some plastics

LOSS OF BIODIVERSITY Biodiversity is defined as the number and variety of species that dwell in a given area. Because the health of an ecosystem is greatly dependent on the existence of established species, extinction of multiple species can prove critical to our environment.

WHAT INFLUENCES OUR DECISIONS? THE ENVIRONMENT AND SOCIETY TODAY

TAKING CARE OF OUR RESOURCES Recall from our earlier studies that resources on Earth are limited. We will consume these faster than they can be replenished if we cannot or do not take care of them!

“THE TRAGEDY OF THE COMMONS” In 1968, Garrett Hardin (an ecologist) published his essay detailing what was, in his opinion, the defining problem with solving the environmental issues of his time. He believed that it was the tension between short and long-term interests that was the fundamental issue that prevented us from solving these issues. What do you think?

“THE TRAGEDY OF THE COMMONS” He chief example was the “commons”, which were grazing fields that were owned by a single village. Commons tended to rapidly fail, due to overgrazing. Psychologically, the citizens overgrazed, because there was no reason to practice restraint. After all, if someone didn’t graze the field, someone else would…

“THE TRAGEDY OF THE COMMONS” Eventually, commons were replaced with individual fields. Now, each owner was responsible for the well-being of a small piece of land. In this instance, owners were much more likely to practice restraint, because they only had the small piece of land granted to them. This kept the fields from being overgrazed.

“THE TRAGEDY OF THE COMMONS” The tragedy of the commons, then, is the idea that we will eventually deplete resources by using them up for short- term gain…even if we know we need those resources in the long run!

“THE TRAGEDY OF THE COMMONS”

ECONOMICS AND THE ENVIRONMENT The economy is a great influence into how we use our resources. Recall the tragedy of the commons, where overgrazing occurred because people took the short-term gain of grazing as much livestock as possible, while ignoring the long- term gain of maintaining the field as long as possible.

ECONOMICS AND THE ENVIRONMENT The law of supply and demand dictate that: The greater the demand for something, the more it is worth. The rarer something is, the more it is worth.

ECONOMICS AND THE ENVIRONMENT A cost-benefit is used to evaluate the costs of taking a certain course of action, and the benefits that may result. This is used to determine the optimum course of action. Be aware, though, that costs and benefits can be evaluated quite differently, depending on the party doing the analysis.

ECONOMICS AND THE ENVIRONMENT A huge part of cost- benefit analysis is anticipating and predicting risk. One reason why different people can come to different solutions is the differences in perception of risk.

POPULATION AND CONSUMPTION As discussed earlier, the pressure behind most of our environmental problems is a result of two issues: Human populations are growing beyond levels that the local environment can viably support. Humans, in general, are using resources much faster than they can be replenished.

POPULATION AND CONSUMPTION Developed Countries Developed countries have higher average incomes, slower human population growth, and stronger social support overall. Resources are more accessible, and are consumed quickly, leading to high levels of waste and pollution. Developing countries Developing countries have lower average incomes, greater human population growth, and may lack critical social infrastructure. Rapid population growth can lead to severe population pressure.

POPULATION AND CONSUMPTION The ecological footprint is the amount of land needed to support one given person. This includes land used for food, housing or materials. It also includes land needed to absorb air pollution at sustainable levels. The carbon footprint is the amount of carbon dioxide generated over a person’s lifetime.

POPULATION AND CONSUMPTION Ideally, the solution we are looking for is a sustainable world. This means that human needs can be met indefinitely, at a suitable standard of living. Creating a sustainable world requires great cooperation to solve both local and global issues threatening the environment.