Agenda -Daily Show video on Global Wobbling -Lecture on: Water Cycle Primary vs. Secondary Pollutants Sulfur, Phosphorous, Oxygen Cycles Homework Read: Fish & Forest article Nutrient Cycle Game (Due Mon; NO LATE GAMES)

Daily Show – Global Wobbling Video /jon-stewart-climate-change /jon-stewart-climate-change

Water Water covers ~75% of Earth Most water is salt water, only about 3% is considered “fresh water” Freshwater: lakes, rivers, streams, groundwater, frozen sources like glaciers, icebergs, snowcaps Almost 70% of freshwater in frozen source (glaciers/icecaps) ~30% exists as groundwater <1% freshwater is surface water (lakes, streams, rivers) Lake Baikal in Russia holds 20% of Earth’s surface water

Water Vapor H 2 O in gaseous state Warm air “holds” more water vapor than colder air At higher temps., water molecules are more likely to go into the vapor phase, so there will be more water vapor in the air As the planet warms, what happens to the amount of water vapor in the air?

El Nino - warm ocean water temperatures that periodically develops off the western coast of South America and can cause climatic changes across the Pacific Ocean

Humans impact on Water Cycle Urban development – nonpermeable surfaces (asphalt) prevent infiltration of water. Runoff increases, which result in decrease of groundwater. Deforestation – also increases water runoff, which results in decrease groundwater levels Withdrawal – remove water for irrigation Add Pollutants – Rain water picks up pesticides, herbicides, fertilizers (rural), and gas, oil, pet waste, salt, human sewage (urban)

Check your Understanding What is the major sink of sulfur? How have humans altered the sulfur cycle?

Check your Understanding What is the major sink of sulfur? In most metal ores (rocks) How have humans altered the sulfur cycle? Burning fossil fuels, produces sulfur dioxide S 8 + 8O 2  8SO 2 Refining metals produces sulfur dioxide too.

Pollution Primary Pollutant – Generated directly from the source of pollution – Ex) Carbon dioxide released by burning fossil fuels Secondary Pollutant – Generated by a combination or chemical reaction between two or more primary pollutants – Ex) Ozone (O 3 ), sulfuric acid (H 2 SO 4 ), nitrogen dioxide (NO 2 )

Photochemical Smog Smog = looks like smoke/fog Photochemical smog is a type of air pollution; common in cities Chemical reaction of sunlight with nitrogen oxides (NOx) and other compounds  results in ozone and other airborne particles

Photochemical Smog Primary pollutants that contribute to smog: NO (nitric oxide), nitrogen dioxide (NO 2 ). These are both produced during combustion of fossils fuels. Secondary pollutants that contribute to smog: surface Ozone (O 3 ), sulfuric acid (H 2 SO 4 ), nitric acid (HNO 3 ), and nitrogen dioxide (NO 2 )

Check Your Understanding Why is phosphorous likely to limit aquatic plant production in an ecosystem? Where in nature can large quantities of phosphorous be found?

Check Your Understanding Why is phosphorous likely to limit aquatic plant production in an ecosystem? P is insoluble, hard to break down, and does not have a gaseous phase which makes it move through the environment very slowly. Where in nature can large quantities of phosphorous be found? Guano (excrement of birds/seals)

Check Your Understanding What is the major source of oxygen gas? What is photosynthesis? How is oxygen involved?

Check Your Understanding What is the major source of oxygen gas? Photosynthesis What is photosynthesis? How is oxygen involved? Process by which plants use carbon dioxide and water (and sunlight) to make glucose and oxygen 6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2 (light energy)