Studying the State of Our Earth

abiotic

nonliving

accuracy

how close a measured value is to the actual or true value

anthropogenic

derived from human activities

background extinction rate

the average rate at which species become extinct over the long term

biodiversity

the diversity of life forms in an environment

biophilia

love of life

biotic

living

control group

in a scientific investigation, a group that experiences exactly the same conditions as the experimental group, except for the single variable under study

development

improvement in human well-being through economic advancement

ecological footprint

a measure of how much an individual consumes, expressed in area of land

ecosystem

a particular location on Earth with interacting biotic and abiotic components

ecosystem services

the processes by which life-supporting resources such as clean water, timber, fisheries, and agricultural crops are produced

environment

the sum of all the conditions surrounding us that influence life

environmental indicator

an indicator that describes the current state of an environmental system

environmental science

the field of study that looks at interactions among human systems and those found in nature

environmental studies

the field of study that includes environmental science and additional subjects such as environmental policy, economics, literature, and ethics

environmentalist

a person who participates in environmentalism, a social movement that seeks to protect the environment through lobbying, activism, and education

fracking

hydraulic fracturing, a method of oil and gas extraction that uses high-pressure fluids to force open cracks in rocks deep underground

genetic diversity

a measure of the genetic variation among individuals in a population

greenhouse gases

gases in Earth’s atmosphere that trap heat near the surface

hypothesis

a testable conjecture about how something works

natural experiment

a natural event that acts as an experimental treatment in an ecosystem

null hypothesis

a prediction that there is no difference between groups or conditions, or a statement or an idea that can be falsified, or proved wrong

precision

how close the repeated measurements of a sample are to one another

replication

the data collection procedure of taking repeated measurements

sample size

the number of times a measurement is replicated in data collection

scientific method

an objective method to explore the natural world, draw inferences from it, and predict the outcome of certain events, processes, or changes

speciation

the evolution of new species

species

a group of organisms that is distinct from other groups in its morphology (body form and structure), behavior, or biochemical properties

species diversity

the number of species in a region or in a particular type of habitat

sustainability

living on Earth in a way that allows humans to use its resources without depriving future generations of those resources

sustainable development

development that balances current human well-being and economic advancement with resource management for the benefit of future generations

theory

a hypothesis that has been repeatedly tested and confirmed by multiple groups of researchers and has reached wide acceptance

uncertainty

an estimate of how much a measured or calculated value differs from a true value