0 models using natural and anthropogenic forcings 05

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Unformatted text preview: 10 1960 1970 1980 1990 2000 300 250 200 150 -450 -400 -350 -300 From IPCC AR4 WG1 Tech Summary 2007 -250 -200 -150 Thousands of years -100 -50 0 50 Atmospheric CO2 (ppmV) Atmospheric CO2 Concentration (ppm) 360 Temperature anomaly (°C) Global land surface temperature changes Observed mean temp by decade 1.0 Models using natural and anthropogenic forcings 0.5 Models using only natural forcings (i.e. solar activity and volcanoes) 0 1900 1920 1940 1960 1980 2000 Year ⚈  Close agreement between observa<ons and models incorpora<ng natural and human forcing ⚈  No apparent temperature increase without human inputs ⚈  Human emissions ≡ rapid increase in global surface temperature From IPCC AR4 WG1 Tech Summary 2007 2006 Temperature devia<on from 1951 ­1980 average Temperature anomaly (°C) -8 -4 -2 -1 -.5 -.2 .2 .5 1 2 4 8 ⚈  Eleven of the last twelve years rank among the 12 warmest years in the instrumental record of global surface temperature (since 1850) From NASA 2007 Global climate change indicators: polar ice caps Global climate change indicators: glaciers and snow cover ⚈  Declining snow cover ⚈  Widespread retreat of glaciers in both hemispheres Grinnell Glacier, Glacier National Park, USA 1938 – 2005 1938 1981 1998 2005 Difference from 1961-1990 (mm) Global climate change indicators: rising sea level 50 Global average sea level 0 -50 -100 -150 1850 1900 Year 1950 2000 From IPCC AR4 WG1 Tech Summary 2007 ⚈  ⚈  ⚈  Global average sea level rise from 1961 ­2003 = 1.8 mm/yr (3.1 mm/yr from 1993 ­2003) Sources = thermal expansion, glaciers and ice caps, Greenland Ice Sheet, Antarc<c Ice Sheet Many Pacific islands threatened Global cli...
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This document was uploaded on 03/27/2014 for the course CONS 101 at University of British Columbia.

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