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.

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.

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.

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.

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.

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

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

Biological Magnification of DDT

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

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)

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)