How do humans impact the environment 1 Population

How do humans impact the environment? 1. Population growth – More people means more resources are used and more pollution & garbage 2. Pollution – Industrialization: factories – Burning of fossil fuels (gas/oil) for factories and cars • Increased carbon dioxide levels in atmosphere

Limited/Finite Resources (have a certain amount of them) • Renewable Resourcescan be replaced with time – Examples: food supply, solar energy, wind energy • Nonrenewable Resources - cannot be replaced once they are used – Examples: fossil fuels (gas, oil, coal), minerals

Acid Rain • Result of air pollution • Burning of fossil fuels releases pollutants into the air • Pollutants mix with rain water and then collect in ponds/streams/lakes/ground • Decreases biodiversity because some organisms can no longer live in the water • Changes/affects food chains/webs

Acid Rain

Global Warming • Caused by the Greenhouse Effect: increase in carbon dioxide in atmosphere, causes temperature of Earth to rise. • Main greenhouse gas: carbon dioxide • Effects: melting of polar ice caps, increase in extreme weather • Why would deforestation make this worse?

Global Warming

Global Warming

What activities produce greenhouse gases? • Agriculture: (releases methane) • Transportation (cars, trucks, buses…): burns fossil fuels • Burning fossil fuels: factories, cars • NOT BREATHING!!!!!!

Global Warming

Global Warming

Ways to reduce pollution and production of greenhouse gases? • • • Car pool Electric cars Public transportation Plant new trees Recycle Wind/solar power Reduce buring of fossil fuel/ gas, and less carbon dioxide released into environment

Use of Herbicides/Pesticides • Can kill other organisms than the ones intended • Can cause pesticide/herbicide resistance – Mutations allow some organisms to survive spraying – They reproduce and produce offspring that are also resistant – Have to find other ways to kill pest… sometimes a natural predator

Why would deforestation make global warming worse? • Trees/plants remove carbon dioxide from the environment to use for photosynthesis • If forests are cut down, then less trees/plants to remove carbon dioxide from the environment • Cutting down trees/forests – Use materials, build/farm on the land – Decreases biodiversity (number of living species in an area like a forest)

Biomagnification • Increase in the concentration of a substance (toxic/poison) in living organisms as you move up the food chain. • (Toxins dumped in water, get eaten or absorbed by organisms)

One more thing: invasive species • Organisms that are brought to an area, not native to that area originally • Why is this bad? – Invasive or non-native(exotic) species compete with native organisms for resources – Prey (kill/eat) native organisms = decrease biodiversity – Change food webs/chains

Examples of Invasive/non-native/exotic Species • purple loosestrife plants: out-compete other plants for food, decreases biodiversity of area • zebra mussels in Lake Erie: out-compete other organisms for food, clog pipes, cling to ships • stink bugs: invade homes, no natural predator • Dutch elm disease: brought over by beetles, has killed half the elm trees in the US = decrease biodiversity.