Science and the Environment

The EnvironmentWhat do you think of when your hear the word

“environment”?

What is Environmental Science? The study of how humans interact with the

environment. This includes the fields of:

Biology- the study of life

Chemistry- the study of chemicals and their interactions

Physics-the study of matter and energy

Earth Science-the study of the non-living parts of Earth

Social Sciences-the study of humans

The Role of Science in Citizenship Science (especially environmental science) plays a

role in our everyday lives We notice changes in our environment and must

work together to solve the negative ones. Water pollution can limit our ability to use water Air pollution can cause health problems such as asthma Toxins in the environment can be absorbed or eaten by

animals

Our Environment Through Time We can divide human interaction into several time

periods: Hunter-Gatherers The Agricultural Revolution The Industrial Revolution The 20th Century

Population Growth and the Environment Due to technological, medical, and cultural changes

during the agricultural and industrial revolutions life spans have become longer and the population has dramatically increased!

This has placed additional stress on the environment as until the 20th Century, few people were concerned with human effects on the environment.

Environmental Problems We can divide our most pressing environmental

problems into three categories: Resource Depletion Pollution Loss of Biodiversity

Resource Depletion

A natural resource is a natural material used by humans.

Natural resources can be renewable or nonrenewable.

Some examples of renewable resources are:

Some examples of nonrenewable resources are:

A resource said to be depleted when a large fraction of the resource has been used up.

Pollution Pollution is an undesired change in air, water,

or soil conditions that adversely affects the health, survival, or activities of humans or other organisms.

Much of earth’s pollution has come from humans. This began in earnest during the Industrial Revolution.

There are biodegradable pollutants and nondegradable pollutants.

Loss of Biodiversity Biodiversity means the number and variety of

species in an area of earth. Extinction is when a species ceases to exist. This

can be a natural process or caused by humans. Organisms are interconnected in our environment.

If one ceases to exist it can threaten a number of other species who interact with it directly or indirectly.

Short-Term and Long-Term InterestsWhen looking at environmental problems we

must balance short-term and long-term interests.

Short-term interests fulfill an immediate need (i.e.: I need water, a new phone, trees for firewood or a house)

Long-term interests fulfill a need in the future (i.e: I will still need clean water in 50 years, planning for retirement, needing a forest in the future.

Economics and the EnvironmentEconomics can also influence how we

interact with the environment:Supply and DemandCosts and BenefitsRisk Assessment

Supply and DemandIn the field of economics if there is more

demand for something, it is worth more. Also, if there is less of something available, it is worth more.

When oil is in shorter supply, gasoline prices go up. The ways for it to come down and less demand (fewer people driving) or more supply (new wells are drilled).

Think of it like tickets to the Superbowl. They are so expensive because there is much demand, but a limited supply.

Costs and Benefits In every situation where we have to make a

decision on our lives, there are costs and benefits. This also applies to how we interact with the environment. Cost is what must be sacrificed to receive a result. A Benefit is how much that result helps us.

A cost-benefit analysis is when the costs and benefits are weighed against each other to see if a decision is in our best interest.

Think of “green” cleaning products. They cost more, but don’t hurt the environment.

Think of store-brand foods. They are cheaper but may not taste as good.

Risk AssessmentRisk Assessment is when we actually weight

the costs and benefits of a decision.1.Let’s look at the risk assessment of

building a dam.

2.Let’s look at the risk assessment of limiting how many tuna fish can be caught by a boat.

Human Population and the EnvironmentHow our population in different areas

affects the environment can be seen in three ways:Local Population PressuresConsumption TrendsEcological Footprints

Local Population Pressures

When populations grow, they require more resources. If they grow rapidly, this can mean that there may not be enough resources.

This can lead to deforestation, animal habitat destruction, species extinction, lack of water or other environmental problems.

This can adversely affect human or other populations.

Consumption Trends

More developed countries tend to use more resources than less developed countries.

Developed countries use 75% of the world’s resources while only comprising 20% of the world’s population. This means that more developed countries create more waste and pollution.

Ecological Footprints An ecological footprint represents the productive

area of earth needed to support one person in a particular country or place.

What does productive area mean? Let’s calculate an ecological footprint! http://footprintnetwork.org/en/index.php/GFN/pag

e/calculators/

Sustainability Sustainability is the condition in which human needs

are met in such a way that a human population can survive indefinitely.

This does not mean that human progress stops. As we develop new technologies, we find ways to work better within our environment.

Currently at the rate we are using Earth’s resources, we do not have sustainability.

To do so we will have to make some hard choices about how we live.