Environmental Science Chapter 1: Studying the State of Our Earth
Let’s review some terms Environment Environmental science System Ecosystem Biotic/abiotic Environmentalist Environmental studies
Environmental Indicators • Are Earth’s life-support systems being degraded by human-induced changes? • Ecosystem services: clean water, timber, fisheries… ? • Indicators show the health and quality of a natural system – not necessarily the cause • Five to focus on in this course: • Biological diversity (genetic, species, ecosystem) • Food production • Global climate • Human population • Resource depletion
Sustainable practices • Requirements: • Environmental systems cannot be damaged beyond their ability to recover • Renewable resources must not be depleted faster than they can regenerate • Nonrenewable resources must be used sparingly • Ecological footprint • Energy, settlements, timber and paper, food and fibers, seafood, carbon footprint, built-up land, forests, cropland and pastures, fisheries, minerals
The process of science • Observations and questions • Forming a hypothesis – what, exactly, is an ‘educated guess’? • Null hypothesis – the statement that can be proved wrong • Collecting data • Important considerations: replication, sample size, accuracy, precision, uncertainty • Interpreting results • Inductive reasoning versus deductive reasoning • Disseminating findings • Terms to keep in mind: critical thinking, theory, natural law
Experimental design • Controlled experiment • One variable to test! independent variable • One group gets the test! experimental group • The test causes the result! dependent variable • The other group allows us to compare! control group • Natural experiment • A natural event acts as an experimental treatment in an ecosystem • Example: study of forest regrowth after a volcano
Challenges of environmental science Lack of baseline data for comparison – there is no ‘control’ planet without humans Subjectivity – one man’s trash is another man’s treasure… but what about the ecosystem? Interactions – natural systems are extremely complex Human well-being – people who are struggling to get their basic needs met are less concerned for environmental issues. These same people may be more impacted by environmental problems.