As outlined in the earlier posting on Addressing Global Warming: Water, potential impacts of global warming range from minimal to catastrophic. Prudence requires that we address these challenges; a key objective is to make our response systems more resilient without major expenditures. This will be beneficial even if effects turn out to be milder than current projections and will improve our capacity to address other unexpected challenges. Improving system resilience will also be critical if worse effects do materialize. In particular, more powerful storms are likely. Coupled with rising ocean levels, higher temperatures, and changing rainfall patterns, such storms could produce major damage.
With increases in summer temperatures and decreases in precipitation, wildfires in the West are expected to increase during the 21st century. Precipitation and water runoff in the spring and summer are throughout the Southwest, particularly in California where wildfires have already been devastating these last few years - in 2007 well over 1000 homes were destroyed. These fires and other major fires in Arizona, Colorado, Oregon, Alaska, and Yellowstone were intensified by a combination of earlier snowmelt (and hence longer fire seasons) and warmer summers. It also seems that earlier fire suppression efforts were a significant factor because they allowed underbrush and fuel (which normally would have been burned off in less intense fires) to build up and then support very intense firestorms.
Another major factor was the population growth in vulnerable areas. Roger G. Kennedy, a former director of the National Park Service, noted in the New York Times of July 18, 2006, that "half of the nation's population growth is taking place in the 10 fastest-growing states; seven of those states rank in the top 10 in the percentage of their population at risk from wildfire. This land rush into the tinderbox makes no distinction between safe and unsafe neighborhoods or building materials. But then, neither does the federal government, which endorses indiscriminate acceptance of fire risk by subsidizing it indiscriminately. Taxpayers build roads and power lines into the firetraps and insure the mortgages of those who live there. When the fire closes in, we pay to rescue the victims. Thus we encourage construction while risking the lives of both homeowners and those who rescue them.... since 2000, suppression and clean up of this annual conflagration has cost more than $1 billion a year"
At the Federal level, there are five agencies responsible for wildfire management - the Forest Service and four elements of the Department of Interior. A recent evaluation by the Government Accountability Office found that they have taken a number of steps to make communities less susceptible to damage and improve their response capabilities. But they still lack an overall strategy, including efforts to improve cost effectiveness, and need to clarify responsibilities for fires which cross jurisdictional boundaries. In addition, they have taken steps to foster fire-resistant communities by reducing vegetation near structures and incorporating fire-resistant materials in structures, particularly roofs, and have helped sponsor a Firewise Communities program which provides a wide variety of information to developers, builders, and home owners on how to reduce fire risk. Implementation is generally the responsibility of the state or local government.
States have also begun to address this challenge. In the aftermath of the devastating 2007 fires, California has implemented a comprehensive set of building codes, but these only apply to new construction. A few other states have begun adapation programs addressing global warming, but most of them barely mention wildfires. Alaska's report, for example, focuses on problems of coastal villages facing rising seas. The utility of prevention measures is well illustrated by Stevenson Ranch, a master-planned community south of Santa Clarita, California, which was built with fire resistance in mind and has escaped unscathed from the last years of wildfires. Retrofitting existing communities is a much more daunting task. One detailed study of a Nevada community showed that every home in the community failed multiple safety measures, but that their fire resistance could be considerably improved with easy and relatively affordable retrofit fixes - an average of $2,500 per house at that time. This is all the more important as cost considerations make it increasingly difficult to protect vulnerable homes in vulnerable locations. One new technology is a fire-resistant sheath which can protect individual homes. It is an unfortunate fact, as the 2007 wildfires in California demonstrated, that available firefighting resources can get overwhelmed to the point that they are simply unable to provide protection to many areas.
The question of financial responsibilities at the grass roots level has also been barely touched. Zoning laws which require construction to new standards help from an overall point of view, but the challenge of retrofitting existing structures remains. Generally, protection upgrades are the responsibility of the individual owner as mitigation grants are typically not available. Laws which require owners to upgrade their protection tend to require relatively low standards and are difficult to enforce. The biggest incentive comes from financial restraints. One requirement is that buyers of properties in fire hazard zones be advised of the risk; making them more liable to insist on fire resistance standards. More immediate is the question of fire insurance, with underwriters insisting on significant mitigation standards and even then setting premiums to match the risk of loss, and mortgage holders insisting on fire insurance. The question of government subsidies is already being hotly debated, as the risks posed by some buildings would necessitate astronomical premiums. The extent to which the government (i.e., the taxpayer) should assume liability for such high-risk buidings is obviously a controversial one.
Overall, the system for fighting firestorms lacks resiliency. Resources are limited and likely to become even more so in the face of budget pressures on state and local governments. At the same time expected higher temperatures, lower rainfall in many areas, and longer summers are all increasing the likelihood of major fires, exacerbated in some areas by extensive beetle damage to pine forests. This gives an urgency to promptly implementing the most cost effective measures, including:
- Implement the GAO recommendation of developing a cohesive national fire suppression strategy which integrates the efforts of pertinent Federal agencies and aligns them with state and local agencies.
- Implement the accompanying recommendation on a cost-containment strategy which clarifies financial responsibilities of various jurisdictions
- Encourage states to set stringent construction requirements in fire hazard zones and reinforce them with appropriate zoning regulations
- Continue research and development on fire resistant structures and disseminate information as widely as possible.
- Work with insurance companies to develop transparent policies and rate structures applicable to homes in fire hazard zones, incorporating agreed levels, if any, of government subsidies.
None of these measures would entail large costs up front costs. Expenditures on increasing the fire resistance of existing structures would be compensated for by lower fire fighting and reconstruction costs, not to mention reduced trauma from destroyed homes.
It is unclear to what extent global warming may be affecting the frequency or intensity of tornadoes, although climate models do project future increases in the conditions favorable to severe thunderstorms
FEMA regularly does assessments of buildings damaged by tornadoes; new construction can incorporate tornado-resistant features and safe rooms can be built into existing structures. But it is an unusual municipality that has requirements in their building codes. One Minnesota town, for example, after being damaged by a tornado, considered using building codes to encourage (but not require) the construction of safe rooms. But even in new construction this can cost $6,000 and perhaps double in retrofitting an existing house.
Although tornadoes cause considerable damage, their relation to global warming, if any, remains uncertain. Modifying existing buildings or constructing new building to resist tornadoes remains expensive - but so is tornado damage. At this point, the only major recommendation that can reasonably be made is to incorporate information on tornado resistance and safe rooms into building codes.
While the association between severe storms and global warming remains questionable, climate models project continued increases in the heaviest downpours, which have already grown significantly in the north central and north eastern states. In 2008, severe floods hit the Midwest (downtown areas of Des Moines and Cedar Rapids were inundated), the Northwest and New England. Then in early 2009, as the Red River reached record levels, Fargo, ND, worked desperately to stem the flood threat; for several days eventual success was in the balance and then emergency levees held.
A major issue when areas are inundated is the flooding of ground floors and underground areas. On April 13, 1992, a tunnel system under Chicago flooded when damage from pile driving collapsed a roof section under the river. The tunnels had been largely abandoned years earlier, but were still used for utility systems and connected to many downtown buildings. Unfortunately, when scrap materials were originally removed, so were emergency doors which could have sealed off individual sections, so the accident flooded the entire network and caused considerable damage. Similarly, in 2001, Tropical Storm Allison poured nearly 3 ft. of rain into Houston's tunnel system in a few days, creating underground rivers that invaded downtown. Since then, flood doors that can block 15 ft. of water have been installed at tunnel entrances. Undoubtedly, the Cedar Rapids flood filled basements and sub-basements (with the extensive building equipment and communications equipment) of most if not all downtown buildings. More recently, a sudden downpour flooded the basement of the Louisville Main Library on August 4, 2009, causing over a million dollars damage.
Severe floods have been part of the history of large sections of the United States. With or without global warming, they will continue, though expected rainfall increases in some regions will probably make them worse, as will continued population growth in many areas. In any case, several issues need to be addressed:
- There is a huge requirement for levees and other flood protection construction. As illustrated by the Fargo episode last year, protection is possible. But any increases in risks mean that in addition to new construction, even existing structures will need reinforcement. Available funds are simply inadequate. There is an obvious need to develop agreed principles for setting project priorities.
- Many thousands of properties are where they shouldn't be - in flood plain areas. Regardless of how protection priorities are set, many of these will inevitably fall outside protected zones and face eventual destruction. One approach is simply to move the property to higher ground - in fact, in Washington state, the entire town of Hamilton, is considering re-locating. Cost considerations alone, however, make this impractical in most situations. Another solution has been for governments to buy out owners and simply demolish old structures. This approach has been used fairly extensively along the Mississippi River, where several thousand buyouts significantly reduced exposures to flood risks. But inevitably, local governments will be faced with the decision of where to draw the line between protected and unprotected. If some people are left out, are they owed compensation? Developing criteria for such tough decisions can be done now rather then under the pressure of a pressing decision.
- Any property owner in a flood zone should assess the potential for sealing off facilities during a temporary inundation, as Houston is now doing with its flood doors on downtown tunnels. Although not easily done for many buildings, including many individual homes, this is certainly feasible for many office buildings, hotels, and apartment buildings.
- These challenges all concern financial responsibility. No one forced people to build, buy, or locate in flood zones, though the situation is clearly exacerbated when flood zones expand and incorporate properties which were originally classified as low or no risk. A basic principle should clearly be that people should be responsible for whatever risk they choose to assume. However, many areas were settled long before there was an appreciation of flood risk and flood insurance has long been subsidized by government (i.e., by taxpayers). And even when properties were uninsured, Federal and state disaster relief regularly compensated owners for losses. A Repetitive Flood Claims Program even allows insurance recipients to rebuild flooded properties and then apply for disaster relief again when the rebuilt property is once more flooded. Subsidized insurance and disaster relief have badly strained state and federal budgets, even without any obvious complications from global warming. Additionally, flood protection and mitigation programs (such as the buyout program mentioned above) are typically funded by the general populace, not just the group being protected. So property owners (taxpayers) in dry areas are forced to subsidize property owners who chose to locate in flood risk areas. This was perhaps a reasonable approach when costs were relatively low and major disasters infrequent. But budgets have tightened and global warming raises the possibility of even larger floods than in the past, so questions on the degree of financial responsibility of individual owners needs to be re-addressed.
Global warming will probably intensify the challenges of firestorms, tornadoes, and internal flooding, though whether or not it will have a really significant effect remains unclear. But there is little doubt in the case of coastal flooding. The first problem is sea level increases. Melting of the Greenland glaciers or collapse of the West Antarctic Ice Sheet could raise sea levels as much as twenty feet - this would inundate both coasts and put all of Florida south of Lake Okeechobee under water. The probability of such an extreme situation is low, but at this point no one is confident about projections decades ahead. However, there is a strong consensus that sea levels will increase by a couple feet this century; there are further indications that sea level increases could be particularly large on the East Coast. In addition, it is almost certain that that storm intensity will also increase. This is particularly worrisome against the background of damage from recent storms - before global warming effects have even become significant. Hurricane Katrina was a fearsome Category 5 storm, but had actually degraded to a Category 3 before it made landfall at New Orleans. Hurricane Ike was extremely large, but it was only a Category 2 when it struck Galveston. Both of these hurricanes caused major damage, but neither of them could have been a surprise. Much of New Orleans is below sea level and protective marshes on the ocean side had been dwindling for years. Galveston had once before been devastated by a hurricane, the deadliest in US history - in 1900 a Category 4 storm put much of the island underwater and resulted in some 6,000 deaths.
So the entire East Coast, from Brownsville, Texas, to Augusta, Maine, is at increased risk; one recent assessment even listed Eastern Long Island as one of the highest risk areas. The West Coast from San Diego, California, to Bellingham, Washington, is also at risk, though sea level rises may be somewhat lower and major storms are less frequent. As mentioned above, Alaska is already concerned about coastal villages facing rising seas; Hawaii has major urban areas directly adjacent to coastlines. Probable results in the decades ahead range from major to catastrophic.
The basic approach to interior flooding - building protective walls - has only limited applicability to coastal flooding. Billions of dollars have already been spent building protective structures around New Orleans, and the levees are generally stronger now than before Katrina. But there is still no comprehensive plan for final flood control, or for engineering to protect New Orleans from Category 5 storms. Only a few other coastal cities, such as New York, have begun assessing potential barrier systems. Such systems would cost billions of dollars, but major flood damage could easily top tens of billions, so barrier systems could certainly be cost effective. Generally, though, the barriers would have to be temporary - protecting against individual storm surges. Protecting against sea level rises is a much more daunting challenge. For New York City, for example, a storm barrier could protect the harbor area, but a sea wall would simply back up the Hudson River until it reached the wall height. At least, the city is systematically assessing the likely impact of sea level rises and storm surges, and some steps are already being taken. So, for example, all new subway entrances and exits are at least 10 feet above the FEMA flood line.
Actions which could be taken now include:
- Gradually re-locate vulnerable facilities to higher ground. Alaska is already working at community relocation plans for several coastal villages. However, this is an expensive proposition even for small groups and is not widely applicable. But land use and zoning regulations can gradually shift vulnerable properties away from the most threatened areas.
- Encourage all cities which have defensible areas to develop at least preliminary assessments of potential barrier projects, and all property owners should be encouraged to assess the feasibility of installing water barriers to protect against temporary inundations.
- Have FEMA begin systematic resettlement planning. Katrina resulted in a massive outflow of refugees from stricken New Orleans. Regional cities, such as Baton Rouge and Houston, went out of their way to accommodate these refugees. However as time wore on, the large numbers of newcomers became burdensome, straining local resources. Other refugees moved to locations throughout the country and were generally absorbed into local populations without any trouble. FEMA worked hard at providing temporary shelters, but had no plans to assist with permanent relocations. Neither did any one else. But in the decades ahead, there could well be more disasters on the scale of Karina and more requirements for significant population relocations. And obviously if sea level increases turn out to be at the higher end of current projections, there could be massive resettlements.
- Continue strengthening building codes and zoning regulations based on evaluations of damages from recent storms.
- Use insurance ratings to strongly encourage property owners to retrofit existing structures to improve their storm survivability.
- Have coastal municipalities, states, and FEMA address how extraordinary damages would be managed. Financial responsibility has already been discussed in regards to firestorms and interior flooding. The scope of those challenges pales in comparison with the potential losses from coastal flooding. Trillions of dollars of assets are at risk and governments are clearly incapable of compensating for such levels of damage. In the end, property owners who have chosen to locate in areas at risk for coastal flooding and storm damage may have to be forced to absorb the bulk of damages; property owners need to have a clear understanding of what risk they face individually.
The effects of global warming remain uncertain. More intense storms are likely; more severe coastal flooding seems almost certain. Catastrophic coastal flooding is possible. Vice President Cheney was roundly criticized for his so-called One-Percent Doctrine, that if there was even a one percent chance that al Qaeda was getting a nuclear weapon, it had to be treated as a certainty in terms of our response. While it may not be reasonable to treat a 1% chance the same as an 81% chance, the core principle is indeed accurate - if there is even a small chance of a really catastrophic event, it has to be taken seriously.
In terms of global warming, there are numerous actions which can be taken now at relatively low cost which would make sense even if significant global warming effects do not materialize, but would also provide critical amounts of resilience if major effects do materialize. Such measures include:
- Owners reinforcing properties to better withstand natural hazards. Governments need to encourage this by use of zoning regulations and building codes. Insurance companies need to encourage this by clear requirements in insurance policies. Mortgage holders need to support this by requiring and verifying appropriate insurance levels. Buyers have to support this by insisting, in their own clear interest, that properties offered for sale include appropriate protection elements.
- Governments setting the example by reinforcing government facilities. Such measures would, in fact, represent a very productive use of economic stimulus funds.
- Continued efforts to develop better protective designs, materials, and systems.
- Systematic assessments of regional vulnerabilities and the development of regional protection concepts, including flood control projects; funding those which are most cost effective.
- Reviewing policies for disaster relief and subsidized insurance programs; developing broadly accepted criteria for determining the appropriate amount of public support or reimbursement to private owners and for necessary modifications in the event of major or catastrophic damages.
- Improving government planning for natural disasters, including comprehensive strategic approaches to natural hazards, clear delineations of jurisdictional responsibilities, improved interoperability of response forces, updated evacuation procedures, and initial concepts of resettlement plans.