Ch 13 Air pollution

Ch 13 Air pollutionPage 350ClimateLONG term prevailing weather conditions at a particular place based upon records taken

Ex Seattle=cool and moist Phoenix=hot and dryFactors that determine climateLatitudeAtmospheric circulation patternsOceanic circulation patternsLocal geographySolar activityVolcanic activity and Distance to the equator!!!

Circulation Patterns

Ozone Shield (pg. 359)*In the stratosphere that absorbs most of the UV from the sun.

*Being destroyed from CFCs!

Chlorofluorocarbons (CFCs)At first were thought to be great nonpoisonous, nonflammable, noncorrosive.Used widely and many sources1970s awareness of their destruction to ozone begins

CFCs discovered to be bad!Within 10 -20 years of being released, they make their way to the ozone layer where they are chemically unstable and break apart.1 CFC molecule can break apart up to 100,000 ozone molecules

Ozone hole (page 360)= a thinning of stratospheric ozone that occurs over the poles during the spring due to the cold weather there

Thinning Ozone EffectsHumans*more ozone goes thru the layer destroying more DNA which is linked to cancer! Animals and PlantsKills Phytoplankton which is a major producer for the oceanic food chain and oxygen producer!

Increased UV also kills amphibian DNA in eggs reducing their populations.

Damages photosynthesis of plants and our crop yield.

Montreal Protocol (pg 362)Good news1987 group of nations agreed to hault production of CFCs1992 developed countries agree to eliminate most cfcs by 1995U.S. agreed to ban all substances that pose a significant danger to ozone by 2000

Bad newsCFC molecules remain active in the stratosphere for 60 120 years

13.3 Global WarmingSimilar to the way light energy travels threw windows but the heat energy cannot escape and make the car warmer*The greenhouses gases trap solar radiation and return it to earth hence warmer the planet!

Major Greenhouse Gases*Water vapor*Carbon dioxideCFCsMethane GasNitrous oxide

* 2 most abundant

CO2 seasonally fluctuates!Plants grow more rapidly in summer therefore using more CO2, therefore causing carbon dioxide levels to drop in the summer.In the winter, leaves and grass decay releasing the stored CO2, therefore causing levels to rise again

But the trend is still UP, UP , and away!Each year the CO2 levels are getting higher and higher

More CO2 = More heat!A comparison of carbon dioxide in the atmosphere and average global temperatures of the past 400,000 years supports this view.

CO2 Build up in urban areas

Global Warming!An increase in the average temperature at the earths surface.This increase is rising at the same level as the increase in greenhouse gasesThis creates the hypothesis that the globe is warming due to greenhouse gases!It does NOT mean that temps are rising at a constant rate or rising in all parts of the world!Consequences of a warmer earth today(page 366)In U.S. some birds are nesting 11 days earlierIn Britain, 200 species of plants are flowering up to 55 days earlierThese are both influenced by temperatures!

Effects of a warmer earthChange in weather patternsRise in sea levelsBut these effects will be different everywhere because:some ecosystems are less sensitive Countries vary in their ability to respond to problems caused by climate changes.

Melting ice and rising sea levelsWetlands and low lying areas disappearHomes lost and sources of incomeBeaches erodedSalinity changes in bays and estuaries

AndCoastal freshwater aquifers become too salty and no longer available for fresh water sources!

Global weather patternsA warmer earth means the oceans will absorb more heat = more typhoons/hurricanes!Change in ocean currents = change in weather!ex- droughts, floods

Human health problemsHeat waves = deathFlowers last longer = bad for allergy sufferers! (ME!)Mosquitos would be able to survive in other areas and spread more disease, etc.

Plants and animalsPLANTSDecrease in crop yields = starvation!Increases the demand on irrigation and therefore drains aquifers even more!ANIMALSMight die due to warmer conditionsSome might shift geographical ranges

Kyoto Protocol1997Requires developed countries to decrease emissions of carbon dioxide and other GHGs by an average of 5% below their 1990 levels BY 2012But by 2035 the developing countries will increase to 50%

Nitrous oxide gives rise to NO (nitric oxide) on reaction with oxygen atoms, and this NO in turn reacts with ozone.Human activity is thought to account for 30%; tropical soils and oceanic release account for 70%.