ZOO507 Midterm Short Highlighted Handouts Lectures 1-46

φ

Environmental Science

THE ENVIRONMENT is everything around us. It includes all of the living and the nonliving things with which We are utterly dependent on the environment for air, water, food, shelter, energy.

ENVIRONMENTAL SCIENCE, an interdisciplinary study of how humans interact with the environment of living and nonliving things. It integrates information and ideas from the natural sciences, such as biology, chemistry, and geology, the social sciences, such as geography, economics, political science, and demography, and the humanities, including philosophy and ethics

Environmental science is an interdisciplinary study of connections between the earth’s life-support system and human activities.

GOALS OF ENVIRONMENTAL SCIENCE

The goals of environmental science are to learn

How nature works?

How the environment affects us?

How we affect the environment?

How to deal with environmental problems and live more sustainably?

A key subfield of environmental science is ecology, the biological science that studies how organisms, or living things, interact with their environment and with each other.

χ

Every organism is a member of a certain species: a group of organisms with distinctive traits and, for sexually reproducing organisms, can mate and produce fertile offspring. For example, all humans are members of a species that biologists have named Homo sapiens.

A major focus of ecology is the study of ecosystems. AN ECOSYSTEM is a set of organisms interacting with one another and with their environment of nonliving matter and energy within a defined area or volume.

We should not confuse environmental science and ecology with environmentalism, a

social movement dedicated to protecting the earth’s life-support systems for us

and all other forms of life.

Environmentalism is practiced more in the political and ethical arenas than in the realm of science.

ENVIRONMENTAL SUSTAINABILITY

Sustainability is the ability of the earth’s various natural systems and human cultural systems and economies to survive and adapt to changing environmental conditions indefinitely

Sustainability

A critical component of sustainability is natural capital—the natural resources and natural services that keep us and other forms of life alive and support our economies.

1. Natural resources are materials and energy in nature that are essential or useful to humans

These resources are often classified as renewable (such as air, water, soil, plants, and wind) or nonrenewable (such as copper, oil, and coal).

2. Natural services are functions of nature, such as purification of air and water, which support life and human economies.

Ecosystems provide us with these essential services at no cost. One vital natural service is nutrient cycling, the circulation of chemicals necessary for life, from the environment (mostly from soil and water) through organisms and back to the environment

Nutrient cycling: an important natural service that recycles chemicals needed by organisms from the environment (mostly from soil and water) through organisms and back to the environment. Natural capital is supported by solar capital: energy from the sun Take away solar energy, and all natural capital would collapse.

ψ

SOLAR ENERGY

Solar energy warms the planet and supports photosynthesis—a complex chemical process that plants use to provide food for themselves and for us and most other animals.

• This direct input of solar energy also produces indirect forms of renewable solar energy such as wind, flowing water, and biofuels made from plants and plant residues.
• For example, topsoil, the upper layer of the earth’s crust, provides the nutrients that support the plants, animals, and microorganisms that live on land; when they die and decay, they resupply the soil with these nutrients. Without this service, life as we know it could not exist.
• Thus, our lives and economies depend on energy from the sun (solar capital ) and natural resources and natural services (natural capital ) provided by the earth

SECOND COMPONENT OF SUSTAINABILITY

A second component of sustainability is to recognize that many human activities can degrade natural capital by using normally renewable resources faster than nature can renew them For example, in parts of the world, we are clearing mature forests much faster than nature can replenish them We are also harvesting many species of ocean fish faster than they can replenish themselves This leads us to a third component of sustainability Environmental scientists search for solutions to problems such as the degradation of natural capital However, their work is limited to finding the scientific solutions, while the political solutions are left to political processes For example, scientific solutions might be to stop chopping down biologically diverse, mature forests, and to harvest fish no faster than they can replenish themselves But implementing such solutions could require government laws and regulations

The search for solutions often involves conflicts

GROWTH OF ENVIRONMENTALLY SUSTAINABLE SOCIETIES

Economic growth is an increase in a nation’s output of goods and services

It is usually measured by the percentage of change in a country’s gross domestic product (GDP): the annual market value of all goods and services produced by all firms and organizations, foreign and domestic, operating within a country

Changes in a country’s economic growth per person are measured by per capita

GDP:

the GDP divided by the total population at midyear.

Consumers in the rich country are said to have more purchasing power than consumers in the second country have

To help compare countries, economists use a tool called purchasing power parity

(PPP)

By combining per capita GDP and PPP, for any given country, they arrive at a per capita GDP PPP—a measure of the amount of goods and services that a country’s

average citizen could buy

While economic growth provides people with more goods and services, economic development has the goal of using economic growth to improve living standards.