Climate change lecture

Climate change lecture - Global and Regional Climate Change...

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Unformatted text preview: Global and Regional Climate Change Nate Kettle Department of Geography Proof of Global Warming Weather vs. Climate Columbia, South Carolina • Weather: Short term (daily to weekly) atmospheric Short conditions we experience. • Climate: Long term average weather conditions Long (seasonal-millennial) (seasonal- Humid subtropical climate (Cfa). Daily mean temperature in Columbia: 44°F in January; 81°F in July. Summer temperatures are hot Average annual rainfall is 48.3 (1971–2000), no marked dry season 1 Theories of climate change • Continents drifting over polar regions • Volcanic activity blocking out the sun • Solar variability • Changes in ocean circulation • Changes in shape of Earth’s orbit Earth’ • Variations in the tilt of Earth’s axis Earth’ • Human loading of GHGs into the atmosphere • Land cover change affects albedo Types of Climate Variability and Change • Cyclical •Sudden Change • Upward Trend •Random variability Types of Climate Change http://www.gseis.ucla.edu/courses/ed230a2/notes/zgraph4.gif; http://www.grida.no/climate/ipcc_tar/wg1/images/fig2-32s.gif 2 1.4°F 57.2 °F Emissions and concentrations 3 Is the Earth Warming? Surface Temperature Data Instrumental Record Red Bars: Average Annual Temp. Red Line: 5 year moving average Proxy Data ex: Tree Ring Analysis Sediment Cores Red Line – Instrumental Record Blue Line – Proxy Data Grey – Error bars Source: IPCC Global T changes What do we know about the ice sheets? Elevation-change rate (cm/year), 1992-2003 Source: Davis et al, 2005 Science 4 Greenland Source: Abdalati, W., and K. Steffen, 2001. J. Geophys. Res., 106(D24), 33,983–33,988. Updated at: http://cires.colorado.edu/science/groups/steffen/greenland/melt2005/ Human and Anthropogenic forcings What do we know about future temperature change? 5 What do we know about future temperature change? from 1980-1999 avg. °C Meehl et al., 2005. Science What don’t we know about future temperature change? The probability of future emissions scenarios. Meehl et al., 2005. Science What will future greenhouse gas emissions be like? Depends on: • Standard of living • Population • Energy efficiency • Carbon intensity of fuels 6 Why Should South Carolinians Care? • Local decisions and actions have global consequences. • In a global economy, economic impacts elsewhere can affect SC. Observed Sea Level Rise Observed SLR 7 SLR US Stoltz and Gill 2005 What are projections for 21st century sea-level rise? CO2 concentrations for different scenarios Temperature change (relative to 1980-1999) Sea-level rise without ice sheet or glacier melting Meehl et al., 2005. Science Are We Impacting Future Generations? Sea Level Rise: 2 meters 24 of XX 8 Are We Impacting Future Generations? Sea Level Rise: 4 meters 4 meter SLR 25 of XX Sea Level Rise Charleston County, South Carolina 80% of the coastal wetlands could be lost Impacts • • • • • Coastal Erosion Salt Water Intrusion Permanent Inundation Enhanced Storm Surge Loss of Wetlands Jensen et al. 1993 Kettle (2006) Popular Culture and Media 9 Commitment What do we know about ocean heat uptake? Annual ocean heat uptake Source: Levitus, S., J. Antonov, and T. Boyer, 2005. Geophysical Research Letters Earth's heat balance components (1022 J), 1955–1998 Energy Budget Source: Levitus, S., J. Antonov, and T. Boyer, 2005. Geophysical Research Letters 10 Are We Impacting Future Generations? Sea Level Rise: 6 meters 6 meter SLR 11 ...
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