ENVIRONMENTAL HUMAN IMPACT PP. 435-444

EARTH’S LAYERS

Hydrosphere: includes oceans, lakes, rivers, and water vapor Atmosphere: mixture of gases surrounding the planet Geosphere: rock interior Biosphere: part of the earth where life (biota) exists

THREATS TO BIODIVERSITY ARROWS INDICATE MASS EXTINCTION Currently in a time of high biodiversity Estimated by 2030, 20% of species will be gone Rainforest biome contains 1/5 of the world’s species but is quickly disappearing

ECOSYSTEM DESTRUCTION Biggest threat to biodiversity due to habitat destruction Loss of biodiversity results in community instability

Invasive species are the second largest threat An invasive species can out compete native species and often lack of natural predators in the area

GREENHOUSE AFFECT The ability of our atmosphere to trap heat keeps our planet warm and habitable

CLIMATE CHANGE

Excess CO2 released from burning of fossil fuels Possible correlation between temperature and CO2 levels Adds to the “greenhouse” to trapping heat Could affect amphibian/reptile development as well as weather and agriculture

HOLE IN THE OZONE LAYER O3 (ozone) makes up the ozone in the upper atmosphere and blocks radiation CFCs from refrigerators and propellants break down ozone Localized in southern hemisphere and increases in size over time (especially OCT)

OCEAN POLLUTION

Entanglement: organisms become twisted in or caught in plastics Ingestion: organisms eat plastics Rafting Organisms: barnacles, sea anemones, and other “rafters” make their home on plastics.

CHEMICALS AND TROPHIC LEVELS

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

ACID RAIN Burning of coal produces H2SO4 (sulfuric acid) and burning of gasoline produces HNO3 (nitric acid) These pollutants enter the atmosphere to form acidic water (acid rain) Some bodies of water can buffer the effects of acid rain Animals and plants sensitive to pH changes suffer the most

RUNOFF Eutrophication is the enrichment of an ecosystem with chemical nutrients containing nitrogen or phosphorus. Eutrophication can lead to harmful toxic algal blooms and hypoxia (or oxygen depletion) High rates of photosynthesis can raise pH to extreme levels during the day.