Introduction to Environmental Science

Environment and Environmental Science

• The term "environment" comes from the French word "environ", meaning "around that which surrounds", and refers to the sum total of all living and non-living elements and their effects that influence human life.
• Environmental science is an interdisciplinary field of study that combines physical, chemical, and biological factors to understand the growth and survival of organisms, populations, and communities.

Goals of Environmental Science

• To learn how nature works
• To understand how humans interact with the environment
• To find ways to deal with environmental problems and live more sustainably

Four Laws of Ecology

• Everything is connected to everything else
• Everything must go somewhere
• Nature knows best
• There's no such thing as a free meal

Biogeochemical Cycles

• The processes by which matter cycles from the living world to the nonliving, physical environment and back again
• Five important biogeochemical cycles: carbon, water, nitrogen, sulfur, and phosphorus

The Carbon Cycle

• Carbon enters the living world through photosynthesis and returns to the abiotic environment when organisms respire

The Hydrologic Cycle

• The continuous renewal of the supply of water and exchange of water among the land, atmosphere, and organisms

The Nitrogen Cycle

• Composed of five steps: nitrogen fixation, nitrification, ammonification, assimilation, and denitrification

The Sulfur Cycle

• Sulfur compounds move between organisms, atmosphere, ocean, and land

The Phosphorus Cycle

• Phosphorus erodes from rock and is absorbed by plant roots

Energy and Pollution

• Energy is the capacity or ability to do work and can be either potential or kinetic
• The First Law of Thermodynamics states that energy cannot be created or destroyed, only changed from one form to another
• Human activities have degraded or overused about 60% of the earth's ecosystem services since 1950
• Pollution is the contamination of the environment by any chemical or other agent to a level that is harmful to human health or the environment

The Tragedy of the Commons

• The degradation of shared or open-access renewable resources due to individual use and exploitation
• When the number of users is small, the logic works, but eventually, the cumulative effect of large numbers of people can degrade the resource and exhaust it

Growing Ecological Footprint

• The harmful environmental impact of human activities, measured by the amount of land and water needed to supply a population or area with renewable resources and absorb and recycle waste and pollution

Poverty and Environmental Degradation

• Poverty is a condition in which people are unable to fulfill their basic needs for adequate food, water, shelter, healthcare, and education
• About 900 million people live in extreme poverty, struggling to survive on less than $1.25 a day
• Desperate for short-term survival, these individuals often degrade forests, topsoil, and grasslands, and deplete fisheries and wildlife populations

Avoidance of Full-cost Pricing

• Companies do not pay for the harmful environmental and health costs of supplying goods and services
• The primary goal of a company is to maximize profits, so it is not inclined to add these costs to its prices voluntarily

Increasing Isolation from Nature

• More than half of the world's people live in urban areas, and this shift is continuing at a rapid pace
• Artificial urban environments and increasing use of electronic devices are isolating people from the natural world
• Many people do not know the full story of where their food, water, and other goods come from, or the amounts of waste and pollutants they produce and how they affect the environment

Human Wellbeing

• Wellbeing describes what is ultimately good for a person: basic needs are met, individuals have a sense of purpose, they feel able to achieve important personal goals, and participate in society