Sometimes it seems that proponents of greenhouse gas mitigation are their own worst enemies. In particular, when mitigation proponents cherry pick among available science to make their political case, it opens the door for mitigation opponents to argue legitimately about science instead of policy and politics. But even worse are cases when mitigation proponents play fast and loose with the science in much the same way as mitigation opponents sometimes do.

A good example of playing fast and loose with science can be found in a recently released report on climate change and the insurance industry by the Association of British Insurers (ABI). The report discusses consequences of climate change for the insurance industry. The report includes a characterization of a recent U.K. government report on floods as an important justification for greenhouse gas mitigation policies. I praised the U.K. Foresight report here on April 28, “All assessments of climate science and policy should be as well done as this one.”

It was apparently so well done that the Association of British Insurers found it necessary to mischaracterize its results. The ABI report’s mischaracterization of the Foresight project’s conclusions on flooding is on page 9:

“The recent Government Foresight report on future flooding estimates that annual average damage from flooding could increase from £1 billion to £2 – 21 billion by the end of the century if no action is taken to tackle climate change and its impacts (Box 2). Initial calculations suggest that future claims costs could be two or three times higher than today’s levels (Table 2). These estimates ignore the effects of socio-economic changes, such as the location and value of assets, and any substantial changes in Government policy.”

It is simply mistaken to say that the Foresight’s estimates “ignore the effects of socio-economic changes, such as the location and value of assets.” In fact the opposite is true.

The Foresight report observes on pages 23-24 that of the 19 different factors that might influence future flooding considered in its work “Precipitation will increase risks across the country by 2 to 4 times, although specific locations could experience changes well outside of this range.” By contrast, “these are difficult to quantify, but the analysis showed a large increase in social risks in all scenarios, by 3 to 20 times.” This suggests that over the next 80 years Foresight concludes that societal factors are likely more significant drivers of flood impacts that climate change per se. This is why the Foresight report called for a portfolio of policy responses that include both adaptation and mitigation.

The ABI report is either grossly mistaken or playing fast and loose with the facts. Either way, they have left the door wide open for their opponents to argue about science rather than policy.

A post script: The author of the AIB report is a former chief author for the IPCC. Perhaps this helps to explain why the section of the IPCC Third Assessment report dealing with Attribution Analyses of Loss Trends, which heavily cited work I and colleagues have done on this subject, concluded rather weakly and a bit fast and loose when compared to the peer-reviewed literature on this subject:

“Based on the findings of TAR WGI, the information summarized in Table 8-1, and the analysis presented above, we conclude that some part of the upward trend in the cost of weather-related disasters illustrated in Figure 8-1 is linked to socioeconomic factors (increased wealth, shifts of population to the coasts, etc.) and some part is linked to climatic factors such as observed changes in precipitation and drought events.”

By contrast we concluded:

“Societal impacts from weather and climate extremes, and trends in those impacts, are a function of both climate and society. Comprehensive assessments of losses and results from several recent studies of extremes establish that losses related to most weather–climate extremes have been on the rise. But, after adjustment of the data for major societal changes, most losses from weather–climate extremes are not increasing. This indicates that most upward changes are due to a mix of societal factors.”