atmosphere and climate

chapter 12

atmosphere• stratosphere• troposphere

• ozone layer• greenhouse effect

• greenhouse gases• H2O• N2O• CO2• CH4

• chemical cycles - affect weather patterns and climate• carbon cycle - CO2 emissions• nitrogen cycle - NO, N2O from heat of combustion• sulfur cycle - fossil fuels like coal, oil

air pollution• health effects

• WHO estimates that air pollution killed 6.5 million people in 2012 - more than double previous estimates

• 3.7 mil ambient; 4.3 mil indoor• indoor vs. outdoor (ambient)

• household pollution• cooking and heating with solid fuel

• ambient pollution• sources vary greatly with region

atmospheric pollution• Air pollutants

• Natural and anthropogenic sources• Volcanoes, fires, dust storms

• Human health impacts • acute, chronic, carcinogenic

• Impacts on plants • agriculture, forestry

• Infrastructure impacts • damage to buildings, bridges,

statues

http://www.flickr.com/photos/phil_p/2082804280/

http://www.mmepr.com/shakedownnews/tag/los-angeles/

• Primary pollutants• Volatile organic

compounds• Particulate• Carbon oxides• Nitrogen oxides• Sulfur oxides• Lead• Air toxics

• Secondary pollutants• Photochemical oxidants

• Ozone• Peroxyacetyl nitrates

major air pollutants smogs• Industrial Smog

• gray industrial fog • SO2 and particulates

combine with humid air • Photochemical Smog

• brown-air smog • Nitrogen oxides and VOCs

react with sunlight • other pollutants

• smog may also contain mercury, lead, and other contaminants as particulate

• acid deposition• causes

• smokestacks• coal-burning, cars

• dry deposition• particulate

• sulfate and nitrate salts• wet deposition

• acid rain, snow, fog• sulfuric, nitric acid

acid rain ocean acidification• absorption of CO2

• carbonic acid• increase in atmospheric CO2 levels

• increase in ocean acidity• relatively quick changes in

ecosystem• effects

• slows production of CaCO3 shells/exoskeletons• arthropods, mollusks, corals

• already linked to pacific oyster decline, decline in corals

climate change• History

• last million years• ice ages and warm trends

• last 12,000 years• pretty warm, stable climate

• evidence• greenhouse effect

• basic understanding• indirect estimates of climate change over 1,000-2,000 years

• tree rings, corals, ice core samples• climate models based on historical data

• atmospheric CO2 concentration

global CO2 emissions

solar variation• what about the sun?

• has that changed?

glacial recession• loss of glaciers

effects of climate change• projected impacts of climate change

2°C change, 450ppm CO2 3°C change, 550ppm CO2 4°C change, 650ppm CO2

forest fires worsen forest fires much worse forest fires / drought increase sharply

prolonged droughts intensify prolonged droughts much worse

heat waves more common, fewer winter deaths major heat waves, deaths from heat increase

deserts spread, malaria spreads deserts spread more, tropical diseases spread tropical diseases spread faster and further

conflicts over water supplies increase irrigation / hydropower decline -- 1.4 billion people water shortage

water shortages for almost all people

water wars, refugees, terrorism increase water wars, refugees, terrorism, economic collapse widespread

some crop increases in temperate zones (decreases in tropics)

crop pests multiply and spread crop yeilds fall sharply in all regions

most mountain glaciers lost half of arctic tundra melts glaciers and ice sheets melt even faster

sea levels rise, flood low lying coastal areas sea levels continue to rise many low-lying cities flooded

extensive coral reef damage coral reefs severely threatened coral reefs, tropical forests, alpine tundra, coastal wetlands collapse

high extinction risk for arctic species 20-30% of plant and animal species face extinction

50% of plant and animal species face extinction

slowing climate change• what can we do?

• cut energy waste• programmable thermostats• insulation• more efficient lighting

• shift to low-carbon energy• wind? nuclear?

• geoengineering• carbon sequestration

• restore natural forests• carbon capture and storage

• global dimming - difficult to know effects• legislation / international agreements

artificial photosynthesis• Berkeley lab

• nanowire array• CO2 reduced to acetyl CoA• methane

acetic acid <— H+ + CO2 <— H+ +O2 <— H2O

discussion questions• Do you think human activities are having an affect on

climate? • Do you think there is anyway to prevent catastrophe?• what do you think about climate change deniers?

• Think of three activities you took part in yesterday that used energy inefficiently. (and thus increased pollution) • how could you improve the energy efficiency of these

activities?