Are Hurricanes Increasing in Frequency and Intensity?

1. Are Hurricanes Increasing in Frequency and Intensity? Luke Annala-Kinne, Dylan Esmonde, Emma McArdle, Rylee Sweeney

2. Al Gore’s documentary, “An Inconvenient Truth,” makes statements such as; “The number of Category 4 and 5 hurricanes has most doubled in the last 30 years.” After looking at the documentary’s website, www.climatecrisis.net, I began to research Gore’s sources. Information regarding hurricanes was mainly from Kerry Emanuel.

3. Frequency vs. Time • Using chi-squared analysis, I found that the chi-squared sum proved the null hypothesis correct- There is not a correlation between the passing of time (and warmer world temperatures) and hurricane frequency.

4. Power Dissipation Index “Although the frequency of tropical cyclones is an important scientific issue, it is not by itself an optimal measure of tropical cyclone threat. The actual monetary loss in wind storms rises roughly as the cube of the wind speed as does the PD.” Nowhere in this paper does Emanuel relate the PDI to the Saffir-Simpson system of categorizing hurricanes. “Increasing destructiveness of tropical cyclones over the past 30 years”By Kerry Emanuel

5. What do the experts say? NOAA Hurricane Modeling • IPCC: • Frequency— “no clear trend” with current debate • Intensity— “more likely than not” that future storms will increase in intensity • NOAA: • Frequency— “variability makes detecting any long-term trends in tropical cyclone activity difficult” • Intensity— “Model studies and theory project a 3-5% increase in wind-speed per degree Celsius increase of tropical sea surface temperatures.” Source: http://www.gfdl.gov/~tk/glob_warm_hurr.html

6. Hurricane Frequency + 10 Year Average

7. 10 Year Average (1851-2006)

8. 10 Year Average + 6 Order Polynomial

9. Category 4 and 5 Hurricanes

10. 10 Year Averaged Categories + 50 Year Trendlines

11. 50 Year Trendline Predictions for 2050

12. Change in Wind Speed

13. Wind Speed Change as a Function of Temperature

14. Temperature Vs. Windspeed

15. Table Of Most Deadly Hurricanes

16. Table Of Most Costly Hurricanes

17. Conclusions • Compounding factors cause fuzzy data and large seasonal variation • Extant hurricane data too unclear to make accurate predictions of future activity • No pattern to indicate a clear increase in frequency or intensity

18. EXCELSIOR