GEOG 111 1st Edition Lecture 10 Outline of Last Lecture I. Temperature TrendsII. Complexities of climate changeOutline of Current Lecture I. Complexities of climate change (cont’d)II. Threats of climate changeIII. Indirect effects of climate changeIV. How should we handle uncertaintyCurrent LectureI. Complexities of Climate Change (cont’d)a. By adding greenhouse gases, atmosphere is warmed, especially the surfacei. Encourages more convection (air transports heat upward because heated air becomes more buoyant)ii. More clouds1. Lower cumulus clouds effectively block shortwave radiation from reaching the surfaceb. Greenhouse effect is pushing the climate towards a limit. If the climate reaches that limit, it will change over a very short amount of timec. Global circulation models- takes the atmosphere and divides it into blocks i. Simultaneously tries to predict what changes will occur in each of those blocks over a specified period of timeii. May take weeks or a month to run a single modeliii. Shortcomings of the models:1. Incomplete understanding of the earth-atmosphere system2. Computer memory and processing speeds are getting much faster but are still limiteda. Best device we have for predicting the future but particulars are not always guaranteed (look for commonalities)d. Other controls of greenhouse gas climate changei. Particulate matter and aerosols1. Reflect short wave radiation (slight cooling effect)2. Increases brightness or cloud albedo of cloudsii. Air quality is increasing even in areas that are rapidly growing1. Less particulate matter in the air but causing more solar radiation in the air2. Due to laws and air quality standardsII. Threats of climate changea. Plant/animal extinctionsThese 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.b. More evaporation (because the water is warmer) more water in the atmosphere (clouds) but also more droughts especially in marginal areas dwindling food supply especially in developing countriesc. More water vapor in atmosphere creates potential for more heavy rain and flash floodingi. Warmer conditions- more convection/thunderstorms where smaller areas get more rain and broader areas less raind. All in all, more hydro-climatic variabilitye. Global warming is concentrated in high latitudesi. Melting ice caps sea level rises/thermal expansion of water costal floodingf. Indirect effects:i. Rapid melting of Greenland ice sheet would significantly influence (slow) the Gulf Stream1. Could put western Europe in an ice age because of salinity differences (melted freshwater meeting salt water) ii. Permafrost melt and methane release1. Stability of soil decreasesiii. Acidification of oceans1. Portion of CO2 goes into oceans which slowly lowers pH2. Marine organisms suffer and die off even from small changesg. How should we handle inherent uncertainty on climate change?i. Over time, global average seal level is continuing to rise1. Could possibly reach a 3’ increase2. Would be catastrophic for costal areasii. Depends on amount of greenhouses gases in the
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