Science and the Environment Understanding Our Environment

Section Objectives List the five major fields of study associated with Environmental Science Describe the major effects of hunter-gatherers, the Agricultural Revolution, and the Industrial Revolution. Distinguish between renewable and nonrenewable resources Classify environmental problems into three major categories

Environmental Science The study of air, water, and land surrounding an organism or a community Included: Impact of humans Small areas Earth’s biosphere

Interdisciplinary Science

Environmental Science To understand and solve environmental problems Studies human use of resources Studies impact of human use

Environment Through Time Hunter-gatherers- Obtained food by collecting plants, hunting and/or scavenging animals Burned grasslands Killed buffalo in large numbers Over hunting caused extinctions of: Giant sloth Giant bison Mastadons Cave bears Saber-toothed cats

Hunted to Extinction

Hunter-Gatherers

Environment Through Time The Agricultural Revolution- Growing and raising food for human consumption Started over 10,000 years ago Human populations increased dramatically Concentrations of people affected environment Domesticated plants from wild plants Slash and burn Causes soil loss, floods, and water shortage Poor farming practice rendered = useless land

The Agricultural Revolution

Environment Through Time Industrial Revolution- Shift to using fossil fuels Efficiency of agriculture, industry, and transportation Mass production = lower cost Machinery reduced land and human labor needed Human populations grew at an extraordinary rate Urban areas grew = more pollution and habitat loss Improvements: Inventions- Light bulb, plastics, pesticides, fertilizers Sanitation Nutrition Medical care

The Industrial Revolution

Local

Spaceship Earth Earth is a closed system Nothing enters but energy from sun Nothing leaves except for heat Some resources are limited Waste produced faster than disposal

Today’s Problems Local problems- Landfills Regional problems- River water shortage Global problems- Ozone depletion & global warming

Resource Depletion Resource depletion- Large fractions used up Natural resources- Renewable- Can be replaced within a human lifetime Nonrenewable- Can’t be replaced within a human lifetime

Pollution Undesirable change in environment caused by introducing harmful substances, excessive waste, heat, noise or radiation Biodegradable-Can be broken down by natural processes Build up faster than broken down Nondegradable-Can’t be broken down by natural processes Build up at dangerous levels

Pollution

Loss of Biodiversity Biodiversity- Variety of organisms in a given area Genetic variety in a population Variety of species in community Variety of communities in ecosystem Extinction- none left Preservation important