1. Global Warming Continued Some final clarifying thoughts

2. Time Resolution Problem http://www.atmos.washington.edu/~dennis/5 71_Lecture_3_Ice_Core_Note.pdf (a good source) http://www.atmos.washington.edu/~dennis/5 71_Lecture_3_Ice_Core_Note.pdf Ice at depth is under lots of pressure and the annual layers all blend together; time resolution is therefore a function of depth At depth, ice flows and shears so depth is not monotonically related to time

3. The Lag Problem What comes first, CO 2 change or temperature change; evidence is limited by time resolution problem at depth (800-1200 years) What comes first, CO 2 change or temperature change; evidence is limited by time resolution problem at depth (800-1200 years)

4. Role of CO 2 Variations Does it trigger or regulate climate change? Does it trigger or regulate climate change? Scientific data exists to equally support both claims Scientific data exists to equally support both claims What does seem clear is that lower CO 2 does lead to cooling but its easier for atmosphere to cool than warm and this is a strongly non-linear process that we do not scientifically fully understand. What does seem clear is that lower CO 2 does lead to cooling but its easier for atmosphere to cool than warm and this is a strongly non-linear process that we do not scientifically fully understand.

5. Most Importantly There is no past climate record available to us with high time resolution (e.g. annual) that shows the climate when the CO 2 level was 370 ppm. There is no past climate record available to us with high time resolution (e.g. annual) that shows the climate when the CO 2 level was 370 ppm.

6. Possible Feedback Amplification CO 2 rises; lower atmosphere warms slightly  increased humidity at tropical latitudes  increased warming; This is the water vapor feedback loop (current situation) Further CO 2 buildup will then activate the phase lagged CO 2 temperature response further elevating temperatures. Effect is largest at high latitudes where most of the methane is stored in permafrost leading to methane amplified global warming. This feedback scenario would operate over a timescale of about 200 years.

7. Bottom Scientific Line CO 2 build up is real and increasing due to rising economies in India and China CO 2 build up is real and increasing due to rising economies in India and China No scientific link or theory is available to predict annual changes in global temperature or sea surface temperature as a function of annual increase in CO 2  we only know this relation on coarser timescales No scientific link or theory is available to predict annual changes in global temperature or sea surface temperature as a function of annual increase in CO 2  we only know this relation on coarser timescales We are probably in the more benign water vapor feedback loop now and therefore it will eventually (soon?) get much worse much faster We are probably in the more benign water vapor feedback loop now and therefore it will eventually (soon?) get much worse much faster

8. Hurricanes as a Diagnostic? Central pressure  directly related to SST Duration  indirectly related to SST Frequency  not related to SST Wind radius  non-linearly related to SST Total Power estimate  best diagnostic but extremely difficult to measure