Environmental Science Chapter 1: Studying the State of Our Earth

Let’s review some terms Environment Environmental science System Ecosystem Biotic/abiotic Environmentalist

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 Natural 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.