18 August 2009

The Disaster Myth: PDD Edition

In an article released this week, Daniel Weiss and Erica Goad the Center for American Progress tell us that,
. . . the growing number of presidential disaster declarations is another warning sign that global warming is already harming our people and economy.
The Weiss and Goad article is just wrong. It perpetuates a myth that is not supported by any research, but is allowed to persist by the supine mainstream scientific community and an overly credulous media. Ultimately the joke is on CAP because making arguments that are demonstrably untrue is a gift on a silver platter for opponents of cap and trade legislation. Even if the legislation were implemented and actually reduced emissions, it would have no impact on presidential disaster declarations. Presidential disaster declarations have not increased due to global warming, but rather, because of policy change and political decisions.

What is a "presidential disaster declaration"? When a disaster occurs such as an earthquake, hurricane or even a terrorist attack, the governor of a state can ask the federal government for assistance. The president can approve or decline the request, and when approved he issues a "disaster declaration." In recent decades the number of presidential disaster declarations has increased. Weiss and Goad explain that this increase is due to global warming and suggest that we can stem the increase by passing cap and trade legislation.
The Senate must promptly follow the House’s leadership by passing a clean-energy and global warming pollution reduction bill. Inaction or inadequate pollution reductions by the government would allow natural disasters in the United States to amplify in scale and frequency.
In 2001 Mary Downton and I published a paper that looked at this exact question in the context of floods.
Downton, M. and R.A. Pielke, Jr., 2001. Discretion Without Accountability: Politics, Flood Damage, and Climate, Natural Hazards Review, 2(4):157-166.
In that paper we looked at climate, damage and politics, and guess which one was responsible for the overall increase in declarations?
Disaster relief legislation since 1950 has consistently tended to expand the scope of disaster responses available to the president. . . . . The[1988] change in FEMA’s mission may well have contributed to a spiraling increase in both requests and approvals of disaster declarations during the Clinton Administration. The risk-reduction mission creates an incentive for FEMA to recommend approval of declarations because, once a disaster is declared, FEMA can more easily influence local redevelopment planning and mitigation efforts. As more marginal events receive disaster designation, states are likely to apply for declarations in other marginal events, encouraged by seeing an increased likelihood of approval.
Interestingly we found that disaster declarations increased by 50% during years that the president was running for re-election. And no we did not identify a new atmospheric oscillation on 4-year timescales (except in the years without an incumbent on the ballot). So what about climate?
Although there is evidence of increasing precipitation in the United States, there is no evidence that this is the primary cause of the increase in disaster declarations. By invoking changes in weather, officials divert attention from the role of population growth, floodplain development, national policies, and presidential discretion in contributing to trends in federal disaster costs related to floods.
None of this should be a surprise. A recent CCSP report on extremes in the United States found no long-term trends in those phenomena that lead to most disaster declarations:
1. Over the long-term U.S. hurricane landfalls have been declining.

2. Nationwide there have been no long-term increases in drought.

3. Despite increases in some measures of precipitation, there have not been corresponding increases in peak streamflows (high flows above 90th percentile).

4. There have been no observed changes in the occurrence of tornadoes or thunderstorms

5. There have been no long-term increases in strong East Coast winter storms (ECWS), called Nor’easters.

6. There are no long-term trends in either heat waves or cold spells, though there are trends within shorter time periods in the overall record.
Scientists do indeed predict that there will be more extreme events in the future. However, to date there is no justification for attributing the increasing costs of disasters or the number of disaster declarations by the president to the emission of greenhouse gases. Convincing arguments for mitigation and adaptation policies can be made having "to find ways to exaggerate the threat."