Human Impact on the Environment : A look at the ozone layer, climate change, acid rain, deforestation, and vehicle emissions…

Greenhouse Effect CO2, Methane and water vapor NATURALLY create a layer that traps heat close to the earth to maintain CO2, Methane and water vapor NATURALLY create a layer that traps heat close to the earth to maintain

Global Warming The more CO2 and Methane there is, the more heat gets trapped! The more CO2 and Methane there is, the more heat gets trapped!

B ecause of us, the greenhouse gases in the atmosphere increase over time causing temp to rise.

What’s a degree or two?? To you, nothing. To the polar ice caps, a lot!! To you, nothing. To the polar ice caps, a lot!! If they melt, they add tons of freshwater to the salt water oceans. If they melt, they add tons of freshwater to the salt water oceans. This change in salinity can change the flow of water This change in salinity can change the flow of water

What’s a degree or two?? We owe our temperate climate to the northern flow of warm waters of the equator We owe our temperate climate to the northern flow of warm waters of the equator No warm water, no warm weather, North America’s climate may be dramatically colder…. Arctic? No warm water, no warm weather, North America’s climate may be dramatically colder…. Arctic?

Invasive Species Organisms not native to our ecosystems Organisms not native to our ecosystems 1. Out compete native organisms for food No natural predators No natural predators 2. Population of invasive species increases 2. Population of native species decreases 3. Invasive species spreads 2. Native species and prey species may die out

Knotweed outcompeting local plants

Emerald Ash Borer killing Ash Trees

Zebra Mussels eat algae

Acid Rain ph of pure water = 7 ph of pure water = 7 pH of normal rain = 5.4 – 7 pH of normal rain = 5.4 – 7 Mixes with CO2 to form a mild acid Mixes with CO2 to form a mild acid pH of acid rain < 5.4 pH of acid rain < 5.4

Acid Rain When fossil fuels are burned, they release sulfur and nitrogen oxides which form sulfuric and nitric acid when they mix with water. When fossil fuels are burned, they release sulfur and nitrogen oxides which form sulfuric and nitric acid when they mix with water.

Acid Rain The pH of lakes, soil, plant life is lowered. Homeostasis may be destroyed! The pH of lakes, soil, plant life is lowered. Homeostasis may be destroyed!

A Beautiful Sunset? A colorful sunset like this may be caused by dust and pollutants in the atmosphere… A colorful sunset like this may be caused by dust and pollutants in the atmosphere…

The acid rain changes the pH of ecosystems, making the environment too extreme for plants and animals.

Deforestation Forests around the world are being cleared at an alarming rate. Forests around the world are being cleared at an alarming rate.

Deforestation involves clearing trees from an area without replacing them.

Today, the problem of deforestation is especially disturbing in the tropical rain forests. Also increases CO2 if trees are cleared by burning! Don’t even benefit from the wood!

Vehicle Emissions Automobile emissions are responsible for… at least 1/2 of all urban air pollution. at least 1/2 of all urban air pollution. about 1/4 of all carbon dioxide released into the atmosphere. about 1/4 of all carbon dioxide released into the atmosphere. Key contributor to ground ozone Key contributor to ground ozone

Other Sources of Air Pollution Industrial emissions Industrial emissions Fossil Fuel Combustion Fossil Fuel Combustion Livestock Livestock

Erosion and Deposition Breaking down and building up of land Breaking down and building up of land Happens naturally but SLOWLY Happens naturally but SLOWLY Rate increases when humans: Rate increases when humans: Knock down trees for development Knock down trees for development Redirect water flow Redirect water flow Strip mining Strip mining

Erosion and deposition AGAIN IT IS ALL ABOUT BALANCE!! AGAIN IT IS ALL ABOUT BALANCE!! Our actions throw off nature’s balance! Our actions throw off nature’s balance!

Ecosystem disruption An endangered species is a population of organisms which is at risk of becoming extinct through all or a portion of its range An endangered species is a population of organisms which is at risk of becoming extinct through all or a portion of its range few in numbers, or few in numbers, or threatened by changing environmental or predation parameters (including humans) threatened by changing environmental or predation parameters (including humans)

Ecosystem disruption A “threatened” species is one that is likely to become endangered in the foreseeable future and that the population is declining. A “threatened” species is one that is likely to become endangered in the foreseeable future and that the population is declining.

Threatened and Endangered Species So what??? Why do we care? So what??? Why do we care?

Human impact on extinction Harvard biologist E.O. Wilson (1993) estimated that Earth is currently losing something on the order of 30,000 species per year — which breaks down to the even more daunting statistic of some three species per hour. Some biologists have begun to feel that this biodiversity crisis — this “Sixth Extinction” — is even more severe, and more imminent, than Wilson had supposed. Harvard biologist E.O. Wilson (1993) estimated that Earth is currently losing something on the order of 30,000 species per year — which breaks down to the even more daunting statistic of some three species per hour. Some biologists have begun to feel that this biodiversity crisis — this “Sixth Extinction” — is even more severe, and more imminent, than Wilson had supposed.