07 December 2009

Do Sloppy Policy Arguments Matter? Part I

The subject of this post is the EPA endangerment finding. But the focus is not on whether or not the finding is appropriate. I am not a legal expert, but I am of the view that the Obama Administration is perfectly justified in advancing the finding, which as I understand it requires a very low scientific threshold -- do specific human activities lead to changes in the environment? And might those changes potentially lead to some degree of harm? I think that both of these thresholds are easily met, though the politics of implementation are likely very difficult. However, the finding itself is not the focus of this post. This post focuses on how some of my research is presented in the EPA endangerment finding and in the EPA response to public comments.

To be clear, nothing in this post should be interpreted as opposing the EPA finding or more generally as opposing action on addressing accumulating greenhouse gases in the atmosphere. This post should be read in the context of a continuing series on the systematic misrepresentation of the science of climate change and disaster losses. Does such misrepresentation matter? Well, it matters to me because it is my research being misrepresented. Here is the latest installment.

On p. 132 of the Technical Summary (PDF) that accompanies the endangerment finding is an image, shown below. The highlighted yellow circle shows a graph with a green line representing dramatically increasing hurricane damage.The endangerment finding does not provide an original source for the graph, but it does point to the IPCC as the source of the overall figure. The overall figure comes from p. 621 of Chapter 14, WG II of the 2007 IPCC report (PDF) and is shown below.

The highlighted text reads:
. . . economic damages, million U.S. dollars (adjusted to constant 2005 US dollars and normalized accounting for changes in personal wealth and coastal population to 2004), and deaths from Atlantic hurricanes since 1900 (data from Pielke Jr. and Landsea, 1998 updated through 2005)
So our work is the source of the graph showing dramatically increasing hurricane damage in the 20th century. The bibliography explains exactly where the data came from:
Pielke, R.A. and C.W. Landsea, 1998:Normalized hurricane damages in theUnited States: 1925-95. Weather and Forecasting, 13, 621-631. with extensions through 2005 at http://www.aoml.noaa.gov/hrd/tcfaq/E21.html
The Technical Summary of WGII, p. 55 (PDF) also shows the hurricane damage graph (TS.15) as follows:

Using an internet archive, I was able to access the NOAA page that presented a non-peer reviewed update of our 1998 paper as of December 2006, which was immediately prior to the release of the IPCC AR4 report. A problem with that data was immediately evident: The NOAA page at that time did not yet have data for the 2005 hurricane season. After publication of the IPCC in 2007 the NOAA page was updated with a value for 2005 of $120B (see it here). So the IPCC must have manually entered a 2005 value, and that value looks to be $100 billion (which is in error), based on my replication of the TS.15 figure shown below (as $120B doesn't match up with the IPCC graph).

There are two problems here insofar as the IPCC is concerned. One is that the IPCC failed to rely on peer-reviewed research in its presentation of the science of disasters and climate change, contrary to its mandate and how it represents its work to policy makers and the public. The second is that the IPCC engaged in its own analysis of data, which also goes beyond its mandate and representation of its activities. In doing so the IPCC introduced a misleading perspective on long-term trends in hurricane damage in the United States, one that found its way into the EPA endangerment finding despite the availability of correct, up-to-date information.

The real story of US hurricane losses can be seen in the following graph, which is peer reviewed (PDF) and has been readily available to the authors of the EPA endangerment finding for almost two years. For that matter it could have been available to the authors of the IPCC, as the paper was completed well before their deadline.

This graph shows clearly that normalized hurricane losses (see the black curve represented an 11-year moving average over 1900 to 2005) have not increased over the period of record. The lack of trends is consistent with the lack of trends in landfalling storms. Our paper concluded:
The two normalized data sets reported here show no trends either in the absolute data or under a logarithmic transformation: the variance explained by a best-fit linear trend line=0.0004 and0.0003, respectively, for PL05, and 0.0014 and 0.00006, respectively, for CL05. The lack of trend in twentieth century normalized hurricane losses is consistent with what one would expect to find given the lack of trends in hurricane frequency or intensity at landfall. This finding should add some confidence that, at least to a first degree, the normalization approach has successfully adjusted for changing societal conditions. Given the lack of trends in hurricanes themselves, any trend observed in the normalized losses would necessarily reflect some bias in the adjustment process, such as failing to recognize changes in adaptive capacity or misspecifying wealth. That we do not have a resulting bias suggests that any factors not included in the normalization methods do not have a resulting net large significance.
In the public comments and responses from the EPA (PDF) a number of reviewers noted that our work was contrary to the implications of the endangerment finding:
Several commenters (1616.1, 3136.1, 4528, 4632R18, 4666, 4670, 4766, and 7020) argue that increasing raw damage totals associated with tropical storm damage in coastal communities are not the result of climate change, but rather are caused by changes in coastal population, wealth of the population, inflation, and poor sediment management practices. A couple of these commenters reference Pielke et al. (2008) as supporting evidence.
The EPA apparently disagrees with the findings in our paper. However, one could argue that the EPA's response was off target (emphasis added in below, see original for the full non-responsive response):
With regard to insured losses from extreme weather events (e.g., coastal flooding), the USGCRP concluded that economic and demographic factors do not fully explain the upward trend in costs or numbers of observed increases in losses. For example, from 1980 to 2004, the U.S. population increased by a factor of 1.3, while losses increased by a factor of 15 to 20 in inflation-corrected dollars. Numerous studies indicate that both the climate and the socioeconomic vulnerability to weather and climate extremes are changing (Brooks and Doswell, 2001; Pielke et al., 2008; Downton et al., 2005), although these factors’ relative contributions to observed increases in disaster costs are subject to debate (Karl et al., 2009). Analyses asserting minimal or no role of climate change in increasing the risk of losses are limited in that they often 1) tend to focus on a highly limited set of hazards and locations; 2) fail to account for the vagaries of natural cycles and inflation adjustments; and 3) fail to normalize for countervailing factors such as improved pre- and post-event loss prevention (e.g., dikes, building codes, and early warning systems) (Karl et al., 2009). The USGCRP concludes that future increases in losses will be attributable to climate change with high confidence as climate change increases the frequency and intensity of many types of extreme weather (Karl et al., 2009). Please see Section 1 of this volume for our specific response regarding the Downton et al. (2005) paper and other studies
Note how the EPA uses Pielke et al. 2008 to suggest that both climate extremes and societal vulnerability are changing. I have shown above that Pielke et al. 2008 cannot be used to support such a claim. In fact, the USGCRP report cited by the EPA concluded that hurricane landfalls have decreased over the long-term.

In Part II, focused on floods, I'll show how Brooks and Doswell 2001 and Downton et al. 2005 also can't be used to support the claims being made by the EPA in the endangerment finding and in the EPA response to public comments (the former paper uses our methods and the second I co-authored).

What we have here is a clear case of extreme sloppiness by the IPCC followed by some very dubious interpretations of the literature by the EPA. Does it matter? Well, it matters to me.