Environmental
This field studies our planet’s natural systems and how humans and the environment affect one another.
These resources naturally replenish over short periods but can become nonrenewable if used too quickly.
Renewable Resources
A testable idea meant to explain a phenomenon.
hypothesis
This 1862 law allowed citizens to claim 160 acres of public land for $16.
Homestead Act
This economic tool compares the gains and costs of an action.
Cost-benefit analysis
This revolution 10,000 years ago created villages, longer lifespans, and more children surviving to adulthood.
Agricultural Revolution
This revolution in the early 1700s was driven by fossil fuels and technological advancements.
Industrial Revolution
Science relies on these two types of evidence.
Observations and measurements
This period of U.S. environmental policy (1780s–late 1800s) focused on land management.
First Period
This type of tax encourages environmentally helpful behavior by increasing prices on harmful activities.
Green taxes
This gas‑destroying chemical group discovered in the 1970s led to the ozone hole.
CFCs
States that experience these tend to have stronger environmental laws.
Environmental Disasters
These types of scientific journals review papers using other experts before publication.
Peer-reviewed journals
Silent Spring raised awareness of this pesticide’s dangers.
DDT
This type of labeling helps consumers identify sustainable goods.
ecolabeling
This concept describes shared resources used unsustainably and eventually depleted.
Tragedy of the Commons
This term describes the total land and water needed to provide resources and absorb waste for an individual.
Ecological Footprint
This type of explanation is broader than a hypothesis and supported by multiple lines of evidence.
Scientific theory
This period formed the national forest and national park systems.
Second Period
Cycling of nutrients through living and nonliving components
Biogeochemical cycle or nutrient cycle
The average American’s ecological footprint is this many times the global average.
3.5 times
This federal agency monitors and enforces environmental laws.
EPA
These are expected observations if a hypothesis is correct.
Predictions
This 1970 law requires environmental impact statements for government projects.
NEPA (National Environmental Policy Act)
Physical items we obtain from the environment (such as sunlight, fresh water, timber, and fossil fuels).
Goods