- Slides: 16
Sample Global Climate Change Issues • • • Global Climate Change Models Uncertainty Sea Level Rise Arctic Sea Ice Changes Global Climate Change and Hurricanes Competing Effects of GHG and Aerosols
Global Climate Change Models Uncertainty
1. 5 to 4. 5º C Change in globally averaged surface temperature with time after CO 2 values in the atmosphere are doubled. The black lines show the 15 years of phase 3 from 2579 climateprediction. net runs, and the red lines show comparable results from 127 30 -year simulations completed by the Hadley Centre on the Met Office's supercomputer.
Sea Level Rise
Local Sea Level Change - Selected Sites 3. 5 cm 7. 0 cm
Why is Sea Level Changing? Sea Level Factors Thermal expansion Glaciers Greenland Antarctica Other eustatic (mass changes) Totals Estimated from observations 2001 est. (cm/cy) 3 to 7 2 to 4 0 to 1 -2 to 0 -11 to 10 -8 to 22 10 to 20
Pannir Kanagaratnam (U Kansas) and Eric Rignot (NASA) Feb. 17, 2006 issue of Science Mass loss of Greenland ice — through enhanced glacier flow and enhanced runoff — is increasing with time (2 X between 1996 and 2005), particularly on the periphery of the glaciers.
Arctic Sea Ice Changes
Shrinking Sea Ice Extent in Arctic: Result of Global Warming? - Yes • High latitudes more vulnerable • Ice-albedo feedback • Perennial sea ice shrinking 9. 6% per decade since 1979 2005 1979 Annual Minimum Sea Ice Extent (DMSP SSM/I)
Global Climate Change and Hurricanes
2005 Hurricane Season: Result of Global Warming? Wilma Katrina Epsilon (26 named storms!)
Atlantic Multidecadal Oscillation: North Atlantic SST anomaly is related to hurricane frequency
Probability Shifting Toward Stronger Tropical Cyclones Power Dissipitation Index (PDI) - A measure of the total power dissipated annually by tropical cyclones in the North Atlantic compared to September sea surface temperature. Note that total Atlantic hurricane power dissipation has more than doubled in the past 30 years. See http: //wind. mit. edu/~emanuel/anthro 2. htm for FAQ about hurricanes and global climate change Emanuel, Nature, 2005
Competing Effects of GHG and Aerosols
Global mean, volume mean ocean temperature GFDL Model Simulations Delworth et al. , 2005 (Geophys. Res. Lett. ) Courtesy of Tom Delworth (GFDL)