Environmental Issues PAGES 435-437, 440-443

Earth’s Layers•Geosphere: Earth’s rock interior that extends from the core to the crust

•Hydrosphere: Portion of Earth that is water

Earth’s Layers•Atmosphere: mixture of gases that surrounds Earth

• 78% N2, 21% O2, 1% other gases such as H2O & CO2

•Ozone: absorbs most of the sun’s UV light

Earth’s Layers•Biosphere: portion of the Earth that contains life•Approximately from 11km below sea level to 9km above sea

level

Environmental Science•The study of the interactions between humans and their environment

Pollution•Putting substances into the environment that cause harm to the air, soil, water and living things

Hole in the Ozone Layer•CFCs (chlorofluorocarbons) from old refrigerators and propellants break down ozone (CFCs are now banned)

•Leads to an increase in UV radiation on Earth, which could increase skin cancer rates

•Think of the ozone layer as sunscreen for Earth

1979

UVA: goes deep into skin, causes aging of the skin, the tanning ray, contributes to development of skin cancersUVB: responsible for sunburns, key role in development of skin cancerUVC: blocked by ozone, but can cause severe eye damage

Global Warming•Excess CO2 released from burning fossil fuels

•Correlation between temperature and CO2 levels

•Adds to the greenhouse effect

Ocean Acidification•Dissolved CO2 levels increase with increasing temperature

•Carbon dioxide (CO2) reacts with water to form carbonic acid (H2CO3)

•Leads to acidification of the water

•Causes coral bleaching and shelled organisms have problems making shells, disrupts food web

Acid Rain (Precipitation)•Burning coal and gasoline produces sulfur dioxide and nitrogen oxides which mix with water in the atmosphere to form H2SO4(sulfuric acid) and HNO3 (nitric acid)

•This causes acid rain

•Acid rain causes disease and death in many organisms as it upsets pH levels in soil and water

•Can irritate human skin and tissues (eyes and lungs)

Acid Rain

Land and Water Pollution•Bioaccumulation: pollutant from the environment enters the food chain through the lowest level

•Biomagnification: increase in concentration of a pollutant moving up the food chain •Organisms higher up on the food chain

have more of the pollutant in their bodies than those at the bottom

Ecosystem Destruction and Disruption•Due to habitat destruction such as logging, damming rivers, draining swamps, etc

•Destruction of an ecosystem leads to imbalances in the ecosystem which can lead to extinction and reduction in biodiversity

Ecosystem Destruction and Disruption•Over hunting/fishing disrupts food webs

•Example: what happens to the levels of other organisms if marlin are over fished?•More tuna and lancet fish, but all others

below them will decrease in number as tuna and lancet fish numbers grow

Ecosystem Destruction and Disruption•Introduction of invasive non-native species (have no predators in the area) disrupts ecosystems as they outcompete native species

Starlings: destroy cropsOutcompete native species, destroy boats and dock machinery

Kudzu: grows very quickly, covering native plants

Walking Catfish!•Eat everything they can, then “walk” to another body of water

https://www.youtube.com/watch?v=m4a-ckzpD0I