GEOG week of 10/19 notes
GEOG week of 10/19 notes GEOG 1003
Popular in Society and Environment
verified elite notetaker
Popular in Geography
This 8 page Class Notes was uploaded by SophieSol on Sunday October 25, 2015. The Class Notes belongs to GEOG 1003 at George Washington University taught by Rain, D in Fall 2015. Since its upload, it has received 37 views. For similar materials see Society and Environment in Geography at George Washington University.
Reviews for GEOG week of 10/19 notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 10/25/15
EXAM NOV 5th Climate Change Planetaryscalelimits o Are humans exceeding the capability of the planet to function sustainably bw 13 and 12 of Earth s land surface has been transformed by human action Planetary boundaries idea 0 quotThe Day After Tomorrowquot 0 Great disaster movie 0 Climate change global warming climate variability Climate change is a form of air pollution but it affects the entire planet to various extents 0 Results from things like combustion The main case of climate change is the rising concentration of greenhouse gases in the atmosphere especially C02 and CH4 which trap infrared heat which would normally be lost to space 0 C02 is produced by burning things fossil fuel and deforestation Carbon sinks Picture of forest is a carbon sink 0 Taken out of atmosphere and being put to use absorbs carbon 0 So deforestation really does a disservice especially since C02 levels are rising 0 CH4 is produced by cattle rice production land lls and gas pipelines quotClimate is always changingquot 0 Not the point 0 The quotgreenhouse effect is normal it is what gives us our atmosphere on earth Car analogy Short wave radiation goes to the surface of the planet some is re ected back gases absorb some energy but it mostly goes to Earth s surface 0 Carbon dioxide and temperature 0 Concentrations of greenhouse gases are increasing which is what is making temperature increase We know this because of evidence like ice cores 0 160000 years ago 0 Correlation between C02 and temperature 0 Gaia Hypothesis planetary regulation Idea of planet as one large organism and is self regulating o Certainties with Climate Change 0 There is a natural greenhouse effect that makes for a livable climate on earth It is at least 15 decrees C warmer than without it 0 Venus is so hot is an example of what could happen to us 0 Nearly universal consensus of temperature rising 0 Clear association between rising temp and gas levels 0 IPCC is 95 certain that humans are a primary cause of climate change 0 Areas of agreement Atmospheric concentrations of greenhouse gases are increasing 0 C02 280ppm in 1750 400ppm today 0 CH4 09ppm in 1750 175ppm today Uncertainties associated with climate change 0 Scientists are skeptical about behavior of carbon in atmosphere How muchhow long do C02 and CH4 remain in atmosphere 0 Many Q s How much carbon is recycled through plantsoceans More deforestation in tropics Will soils emit more carbon in a warmer world 0 Radiative effects ability to attract heat and residence times how long it stays in atmosphere C02 has a long residence time but milder radiative potential CH4 has a shorter residence time but has 20 times the radiative potential 0 20 times more effective of trapping gases 0 you really don t want methane in the atmosphere CFCs have a long residence time and a high radiative potential and it destroys the ozone layer 0 These have been banned 0 New and improved modeling efforts Linked models run the same parameterized routines for smaller and then link the results back to the larger global model Feedbacks between land useland cover and atmospheric circulation 0 Could climate be changing for other reasons Changes in solar input Changes in earthsun geometry Milankovitch theory of ice ages o Looked at places where earth seems to be wobbling on axis which he thought were cause of ice ages Changes in surface characteristics like re ectivity roughness and surface wetness Deforestation affects these Changes in atmospheric composition Ie volcanic activity aerosols 0 With greenhouse cases don t contribute much 0 Has global warming already occurred Yes Urban heat island effect 0 People live in cities building warm up ground 0 Weather stations are often located at airports o For aircraft reasons 0 Think about Dulles and urban heat effect how it used to be quotout therequot but as area became more developed could this have contributed to temp rising o quotHotlantaquot o Asphalt concrete buildings 0 In Atlanta 0 Intergovernmental Panel on Climate Change IPCC 0 International body for assessing the science related to climate change 0 Produce a lot of graphs Ie the variation in the Earth s surface temperature Impacts of climate change 0 Higher temperatures All around planet Sensors tell us this Main temp changes occur at poles o Modi ed rainfall patterns Wet areas have been getting wetter dry areas have been getting dryer Sealeveldse 0 Natural ecosystem changes Weeds grow better in higher temperatures rise in weed growth 0 Challenged water resources Rainfall to areas that are super dry 0 Opportunity for better governance 0 Observed Impacts 0 20th century average surface temperature 08 degree C O O O O O A greater rate of change than any seen in more than 10000 years Decreasing snow and ice cover Sea level rise 120 cm in 20th century Meltingthermal expansion Precipitation 05 1 per decade over midhigh latitudes Projected impact if trends continue a temperature rise of 3 degrees C will occur before the end of the next century 0 Limitations on predicting the future 0 General circulation models GCMs are models complex computer simulations Models where certain parameters such as C02 can be modi ed Hard time predicting what storm path will be Best tools available Limitations Results vary among models Simplistic representations of oceans ice clouds 0 Makes precipitation predictions uncertain Model resolution and topography are coarse Only do somewhat well reproducing current conditions Cannot predict climate variability and extreme weather 0 Global climate change response Impacts Mitigation reduce impact 0 Reducing amount of greenhouse gasses emitted per year Europe has a reason to worry Extreme cooling due to possible loss of warm ocean currents London is very north but has a lot of green and doesn t stay warm Europe stays very warm from gulf stream bringing warm water from tropical Atlantic Thermohaline circulation sends Europe into a deep winter 0 Big temperature conveyor belt 0 Big fear is that this will slow down and will send Europe in to deep cold winter Drought Dry land Africa drought in western and southern Africa 0 Removed surface vegetation has effect on surface conditions Rainfall variability modulated by vegetation dynamics Species loss Impacts on livelihoods Food impacts 0 People decide to have more kids as a result 0 Western US 0 CO is dependent on snowpack for water 0 CO river basin is experiencing a 55 percent drop in average snowmelt 0 Since 1999 the driest of 98 years of recorded history 0 2 years of successive dryness drought BAU business as usual o If we don t do anything different Assumes people will not want to change 0 Adaptation 0 Global climate equity issues Trouble at the poles 0 Most startling changes are in the high latitudes o Permafrost is becoming less and less common A piece of ground that has remained frozen for at least 2 years 0 Albedo re ectivity Impacts on the Cryosphere 0 Some models predict that all permanent ice will be gone by 2080 Many controversies o Greenland has 8 of world s freshwater supply 0 Sea ice meting does not affect sea level Already displacing an equivalent amount of sea water Antarctica ice shelf has been melting more quickly Sealevelnse 0 Michael Oppenheimer professor of Geosciences and international Affairs Princeton university If there is a 3 degree warming over the 21st century there would be complete melting of the Greenland ice sheet 7 meter sea level rise worldwide 0 Southern Florida would be completely covered 0 For every 1 degree of warming 23 meters of long term sea level rise 0 All ports at sea level would be gone Farming at sea level would be gone 0 OOO 0 Whole areas of the world would have to be remade London 0 Protect or abandon Depends on pace of sea rise 0 LECZs o Took all of censuses of world and put into 1km grid Estimated populations at risk of sea level rise 0 About 22 world land area 11 population lives here China is biggest Then other Asian countries who are vulnerable to sea level rise Climate Change Science and Policy Marcus Saro m A Path to Regulation and A Career 0 Clean Air act 1970 Regulate motor vehicles air pollutants that come from them Once you ve regulated a pollutant under one section you can do others 0 Greenhouse gasses proving they are air pollutants If they are a danger regulation is necessary 2009 nal endangerment nding 0 Climate Science 0 What drives it Greenhouse gas concentrations Aerosols warming or re ecting Cutting trees changes in sun and clouds 0 Changes on a physical scale Temperature precipitation sea level rise Many uncertainties Nonclimate changes like fertilization o Impacts Human health from changes in heat air quality mosquito inhab ance Infrastructure 0 Sea level rise Agriculture 0 Drought Ecosystems C02 Concentrations 0 19505 people began to realize that we were in uencing C02 levels 0 800000 years of C02 history Correlated with ice ages and interglacial o How do we know People take ice cores 0 You get bubbles trapped in ice from layers of snow over time 0 You can see layers and determine when the bubbles came and the concentration of the gas in it Ralph Keeling began to measure C02 concentration in late 19505 We care because it absorbs infrared radiation 0 Climate variability from el ninola nina years Cooling from volcanic eruptions Future projected temperatures 00 0 Temperature change over next century will be a lot greater than 0 past century Warming is not uniform more warming over land Indicators of climate change 0 00000000 0 Sealevelnse Ocean heat content Artic sea ice Upper atmosphere temperatures Glacial met Plant bloom dates Bird migrations Insect habitable zone Changing precipitation patterns River thaw contests Summary 0 O O O GHG s have changed composition of atmosphere Average temps are rising artic sea ice and glaciers are shrinking What is happening now cannot be explained by natural factors aone Gases stay in atmosphere for many years so we are committing ourselves to continued climate change Balance between mitigation adaptation geoengineering and inacUon
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'