Human Impact on the Biosphere Humans depend on the Earth’s products and have altered the Earth’s landscape since their evolution.

Hunting and Gathering likely caused some extinctions

Agriculture allowed for population growth & civilizations

Industrial Growth and Urban Development -created pollution and used a lot of energy

Resource Management Resources- environmental goods or services: water, air, land, forests renewable- regenerate within a short period of time (100 years)

Resource Management non-renewable- cannot be replenished quickly by natural processes

For the Future Sustainable Development - ways to use resources without depleting/ degrading them so they are available for future generations ex: fast growing wood like bamboo and use of beneficial insects

Human Impact Keep in mind that the greater the biodiversity, the healthier the ecosystem is.

Habitat Destruction- a decrease in the quality or quantity of natural areas.

Habitat Destruction Pesticides - chemicals that poison pests may cause the pests to become resistant to the poison or may enter water supplies and become biologically magnified (bioaccumulation or biomagnification) ex. DDT

DDT was used to kill mosquitoes along with other insects It softened the egg shells of birds

Human Impact Acid Rain- the combustion of fossil fuels creates nitrogen and sulfur compounds released into the air; they combine with water to form acid rain

Acid Rain – pH levels

Acid Rain - distribution

Some Effects of Acid Rain

Deforestation loss of forests may lead to extinctions, habitat fragmentation, soil erosion and desertification

Deforestation fragmentation – animal habitats are divided unnaturally

Deforestation migration corridor – animals pass under the highway

Invasive/Exotic Species apparently harmless plants and animals that humans transport into an ecosystem; they have no natural predators and the native species have no defenses

Mongoose brought to Hawaii to take care of the rats that were introduced (mongoose are diurnal and rats nocturnal)

Zebra mussel introduced to the Great Lakes by ocean-going ships; they are native to Eurasia so have no predators; clog pipes and outcompete native species

Africanized Honeybee African and South American bees were hybridized to increase honey production; these hybrids are more aggressive and have a shorter growth period

Lionfish Native to the Western Pacific Ocean it was released into the Atlantic during Hurricane Andrew; impacting the fishing industry by eating native species and their young

Kudzu Originally brought from Asia for landscaping; has no natural predators and just continues to grow

Humans & Climate Change Greenhouse Effect- the Earth’s atmosphere contains gasses (CO2, H2O, CH4) that trap some of the incoming solar heat; this creates a stable temperature on the planet.

Global Warming climate records show a slight warming trend melting ice caps are a result of this.

Global Warming A possible source of this change is the carbon dioxide increases from deforestation and emissions from fossil fuels.

Ozone Layer Depletion Caused by CFCs

Thickness of Ozone Layer