Guest post by Indur M. Goklany
Despite the press given to hurricanes on the dangers they pose to life and limb, in the larger scheme of things, their contribution to U.S. mortality (less than 0.01% on average each year) verges on the trivial. More importantly, death rates are substantially lower today than they were in decades past.
In the following, I am assuming that the catastrophic failure of the levees after Hurricane Katrina should be attributed to hurricanes in general, rather than human failure–a questionable assumption. Also, I am assuming 1,525 deaths from hurricanes in 2005 (see below).
Figure 1 shows that 46% of all deaths from extreme weather events in the U.S. from 1993-2006 were from excessive cold, 28% from excessive heat, 10% from hurricanes 7% from floods, and 4% from tornadoes. Together they were responsible for an average of 1,301 deaths each year. To put these numbers in context, they constitute only 0.05% of the 2,367,000 deaths that occurred each year in the U.S., averaged over 1993-2006. Thus, hurricanes contribute, on average, about 0.006% to total U.S. mortality.
Figure 1: Average annual deaths from extreme weather events, U.S., 1993–2006.
Long term U.S. data on hurricane fatalities show that from 1900–09 to the 2009–10, hurricane deaths and death rates declined by 82% and 95%, respectively (see Figure 2).These estimates use data from the National Hurricane Center (NHC) provided in Blake et al. (2007) which has 1,525 deaths for 2005, the year of Katrina.
[Note that this month, the NHC, via Blake et al. (2011), put out a new report which has 1,225 deaths for 2005, while NWS’s Weather Fatalities website uses 1,016 for that year. I plan to keep on using the older NHC/Blake et al. estimate, pending consultation with Dr. Blake. I have contacted him, but to no one’s surprise, least of all mine, he has much more important things to do right now.]
Figure 2: U.S. hurricane deaths and death rates per year, 1900–2010. Sources: Updated from Goklany (2009), using USBC (2011) and NWS (2011). For 2005, this figure uses National Hurricane Center data from Blake et al. (2007), which has 1,525 deaths for that year, but Blake et al. (2011) has 1,225 deaths while NWS Weather Fatalities uses 1,016 deaths. This figure uses the Blake et al.’s older data, pending consultation with Dr. Blake.
Note that for the U.S., the cumulative average annual deaths from extreme weather events declined by 6% from 1979–1992 to 1993–2006, despite a 17% increase in population. On the other hand, all-cause deaths increased by 14% (Goklany 2009). That is, society is coping with weather related events better than it is for other more consequential health risks. This suggests that it is worth investigating whether public heath might not be better served if resources expended on limiting greenhouse gas emissions were, instead, used to reduce these more important health risks.
If it’s warming, why are hurricane deaths and death rates going down?
If temperatures are supposed to have increased both globally and in the U.S. and if, according to many warmists, warming should have—all else being equal—made hurricanes more destructive, why have deaths and death rates from such events actually declined over the long term?
There are several possible explanations for this:
1) Neither the globe nor the U.S. is warming;
2) They are warming, but warming does not increase the frequency, duration or intensity of hurricanes;
3) Warming does increase the frequency, duration and intensity of hurricanes, but all else is not equal because our adaptability (i.e., adaptive capacity) has increased more rapidly; or
4) Warming does not increase the frequency, duration or intensity of hurricanes and our adaptability has increased more rapidly.
I tend to favor number 4.
First, Atlantic hurricane frequency has not increased since the late 1800s despite any warming of sea surface temperatures (Vecchi and Knutson 2011). More significantly, as indicated by Dr. Ryan Maue’s estimates of global and Northern Hemisphere Accumulated Cyclone Energy (ACE) from 1971 to the present (July 31, 2011) indicate that they are close to their lowest levels since the late 1970s (see Figure 3) (Maue 2011, 2011a). Additionally, the global frequency of tropical cyclones is also close to its lowest levels in the past decades. These patterns are not consistent with claims that higher greenhouse gases will lead to higher temperatures which would increase the frequency and intensity of hurricanes.
Figure 3: Global and Northern Hemisphere Accumulated Cyclone Energy: 24 month running sums through July 31, 2011. Note that the year indicated represents the value of ACE through the previous 24-months for the Northern Hemisphere (bottom line/gray boxes) and the entire global (top line/blue boxes). The area in between represents the Southern Hemisphere total ACE. Source: Maue, R (2011a), at http://coaps.fsu.edu/~maue/tropical/, visited 27 August 2011.
Second, as articulated here, for a variety of reasons—many related to easy availability of cheap fossil fuels and improved forecasting capabilities—our ability to cope with disasters in general, and hurricanes in particular has gone up.
Blake ES, Rappaport EN, Landsea CW. 2007. The Deadliest, Costliest, and Most Intense United States Hurricanes from 1851 to 2006 (and other Frequently Requested Hurricane Facts), Apr 15, 2007. Available at www.nhc.noaa.gov/Deadliest_Costliest.shtml. Accessed Sep 26, 2009.
Blake ES, Landsea CW, Gibney, E.J. 2011. The Deadliest, Costliest, and Most Intense United States Hurricanes from 1851 to 2010 (and other Frequently Requested Hurricane Facts), August, 2011. Available at http://www.nhc.noaa.gov/pdf/nws-nhc-6.pdf. Accessed 22 August, 2011.
Goklany, IM. 2009. Deaths and Death Rates from Extreme Weather Events: 1900-2008. Journal of American Physicians and Surgeons 14: 102-09.
Maue, RN. 2011. Recent historically low global tropical cyclone activity, Geophys. Res. Lett., 38, L14803, doi:10.1029/2011GL047711.
Maue, Ryan N. 2011a. Global Tropical Cyclone Activity Update, visited 15 August 2011.
NWS (2011). Weather Fatalities, visited 14 August 2011.
U.S. Bureau of the Census. 2011. Statistical Abstract of the United States: 2011, visited 14 August 2011.
Vecchi, G.A. and Knutson, T.R. 2011. Estimating annual numbers of Atlantic hurricanes missing from the HURDAT database (1878-1965) using ship track density. Journal of Climate 24: 1736-1746.