SWES 210 1st edition Lecture 9 Outline of Last Lecture II. primary pollutantsIII. sourcesa. naturalb. man made c. biologicald. particulatesIV. coal burningV. volatile organic compoundsVI. secondary pollutantsVII. greenhouse gasesa. excess greenhouse gasesb. the keeling curvwec. smogd. ozonee. montral protocol vs Kyoto protocol and clean air actOutline of Current Lecture VIII. weather vs climateIX. how do GHG’s warm atmospherea. greenhouse effectb. most abundant greenhouse gasc. GHG with most impact on atmX. Studying past climatesa. Ice coresb. Sediment coresc. Tree ringsd. OtherXI. Studying current conditionsXII. Studying future climatea. Climate modelsi. Natural climate changeii. Biological climate changeiii. Anthropogenic b. Trends= the keeling curvec. Future trends= temperature, precipitation, sea levelsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Current Lecture- Weather vs. climateo Weather= current state of the atmosphere. Acts on short timescales and hard to predicto Climate in areas of long term atmospheric conditions (trend) over longer timescales The average weather over a number of years Years, decades, centuries- Climate is complexo Wind patters (coriolis effect, pressure systems, geologic features)o Varying received sunlight in certain locations (seasons, milankovich cycles,o Magnetic field variationso Ocean absorption and ocean currentso GHG’s and cloudso Heat within our atm- A balanced climate systemo When sunlight reaches our atmosphere it is either Reflected (clouds, snow, or beaches) Absorbed (oceans, low albedo surfaces)o For earth to be in balance, incoming energy= outgoing energy- How do GHG’s warm atmosphereo Earth surface absorbs solar radiation, emits heat in Infrared radiationo Some gases only react with certain wavelengths of the light spectrum (greenhouse gasesabsorb IR) Causes excited state of moleculeo Molecule can become stable by releasing (emitting) the absorbed IRo Moelcules release IR in all directionso Can be reabsorbed by other gases in atmosphere, warms troposphere and surface Known as the Greenhouse effect- Which is the most abundant greenhouse gas in the atmosphere?o Water vapor- Other greenhouse gaseso Methaneo Carbon dioxideo Nitrous oxideo Hydrochlorofluorocarbons (HFC’s)- Which greenhouse gas has the most impact on the atmosphere?o Hydrochloro-fluorocarbons (HFC’s)- Not all greenhouse gases are bad, but too much of anything can be damaging- Studying past climate- sediment corfeso Cores drilled into sediment beneath water Preserved pollent Fossilized plant materialo Marine sediment cores- Studing past climate- tree ringso Width of tree trunk in cross section shows how much a tree grew during seasono wide= more growth, wetter yearo skinny= less growth, drier yearo evidence of fire- studying past climate- othero packrat middens- nests made in caves and other remote locationso coral reefs- new layers of coral incorporate isotopes current ocean conditions- study current conditionso daily, hourly yearly reading of: temperature, wind speed, rainfall, air pressureo chemistry of atmosphere and oceanso satellite- studying future climateo climate models combine what is known about the atmosphere, ocean and land interactions to simulate future climate processeso provide start information set rules runo test accuracy by entering collected data and running model towards present- how can climate change over timeo naturallyo biologicalo anthropogenic causes- natural climate fhangeo milankovitch cycles vary how earth receives its solar radiation glaciation periodso changes in solar outputo meteorite impactso ocean absorptiono ocean circulation patterns (el nino, la nina)- anthropogenic causeso deforestationo increasing greenhouse gases burning fossil fuels transportation mining industrial manufacturingo agricultureo population growth- trends- the keeling curveo charles keeling started taking measurements of CO2 from Hawaiio 315 ppm 396 ppm o now over 400 ppm- trends- GHG’so ice core sample have allowed us to gain better understanding of how GHG’s are changingo start of industrial revolution – 1800- future trendso temperature .7 degre F rise over next two decades by end of 21st centure, 3.2-7.2 degees F riseo precipitation rich get richer, poor gets poorer warmer atmosphere increases evaporation= holds more water due to complex weather patterns, arid regions get less wetter, humid regions getmoreo sea levels melting of glaciers= freshwater runoff into oceans rise of sea level 3mm/yr since 1993 (vertical vs. horizonal) lead to coastal flooding, beach erosion, greater storm surges, population