1. Earth’s Layers
Earth’s geosphere, hydrosphere, and atmosphere are interconnected in many ways.
Together, these parts make up the biosphere, the part of the Earth where life exists.

2. Earth’s Layers, continued
Hydrosphere
A very small portion of the hydrosphere is fresh water, and much of this fresh water is not easily usable.
Geosphere
The geosphere exchanges materials with the atmosphere, hydrosphere, and biosphere.

3. Pollution
Over a short time period, human activities have affected global ecosystems in ways that harm humans and other species.
Human impacts range from local pollution to global change in ecosystems.

4. Pollution, continued Ozone Thinning
Industrial chemicals called chlorofluorocarbons (CFCs) act as catalysts in chemical reactions that break down O3 molecules in the ozone layer.
Most countries have banned CFCs, and the ozone layer seems to be recovering.

5. Pollution, continued Global Warming
The correlation of increasing atmospheric CO2 and rising global temperature suggests a cause-and-effect relationship.
Considering several types of evidence, many scientists have concluded that increased CO2 levels have caused warmer surface temperatures on Earth.

6. Pollution, continued Acid Precipitation
Certain air pollutants (sulfur dioxide and nitrous oxide) cause acid precipitation, which harms or kills many organisms.
These air pollutants are released by the burning of fossil fuels

7. Pollution, continued Land and Water Pollution
The release of toxic chemicals, such as DDT, into the biosphere can impact ecosystems in many ways, especially when chemicals undergo biological magnification.
These pollutants are consumed by organisms, and it is collected in their body tissues
Pollutants are not broken down, so the concentration increases as it goes up the food chain

8. Biological Magnification of DDT

9. Invasive Species
Any non-native species that, when introduced into the environment, causes harm to the organisms that are native
Invasive species lack predators and may grow out of control, rapidly using resources meant for the native species
This will disrupt an ecosystem’s balance

10. Human Resource Use
Current levels of human resource use are probably not sustainable
Sustainable development focuses on the careful use of renewable resources (those that can be produced or replaced by a healthy ecosystem)
Nonrenewable resources, such as coal, oil, and natural gas are those that cannot be replaced (when they are gone, they are gone)

11. Conservation and Restoration Biology
Conservation biologists are concerned with identifying and maintaining ecosystems, while restoration biologists are usually involved with repairing badly damaged ecosystems
These types of biologists, along with others who value sustainable development, focus on providing for human needs while being conscious of energy use and of not harming the environment and depleting resources (i.e., solar panels on homes)