- Causes of Future Sea Level Rise
- Elevation Maps
- Will we really lose all that land?
- Sea Level Rise Planning Maps
Given the uncertainties about how much the sea will rise, it is possible that a given parcel of land that seems vulnerable today will not be submerged—at least within the next few centuries. Perhaps global warming will be reversed and the sea will rise more slowly or even begin to fall. Perhaps the sea will simply rise more slowly than the rate that seems prudent to plan for today. If this is the case, then the owner of the parcel will be able to retain the land after all. The holder of the rolling easement will have accomplished nothing for having managed the rolling easement on that parcel; but this is a risk that land trusts and governments will often be willing to take. Like all precautionary measures, the rolling easement proves to be worthless only if there is some very good news: The sea rose so slowly that the adjacent coastal wetlands were not submerged and hence did not need this property for the habitat to survive.
Assuming that sea level continues to rise, however, most dry land within a few meters above the tidal wetlands today will eventually become submerged Figure 6 depicts a possible scenario for a home along a wetland shore. Driveways and sidewalks are removed as the wetlands advance, but the preexisting home remains. Storms are less likely to destroy a home along a wetland shore than a home along the ocean, so the home continues to stand. Eventually, the home is standing seaward of mean high water and hence is on state-owned land. The fate of the building after that point is not necessarily part of the rolling easement but instead depends on how the state regulates nonconforming structures standing in state-owned tidal wetlands or open water. Nevertheless, one option may be for the state to allow continued occupation for a limited time, in return for an escalating rent based on the fair market value of the location. The increasingly imminent abandonment and escalation of costs associated with a structure in the wetlands would tend to cause a gradual decline in the market value of the property.
That is just one of many scenarios. This chapter examines how they may play out, starting at the time when submergence appears to be sufficiently imminent to affect decisions by the landowner, continuing with measures that the rolling easement can require in preparation for the submergence, and finally looking at the actual submergence and conversion of the property from dry land to publicly owned wetlands and waters.
A key economic and policy justification for rolling easements is that they cost less than either preventing development or failing to plan.
For the typical coastal parcel, submergence by the rising sea is so uncertain and far in the future that it has no practical impact on how an owner uses the land, whether or not there is a rolling easement. If development is cost-effective, the owner may develop, and thereby derive more use from the land than leaving it undeveloped. Although a no-development easement would limit the owner’s ability to profitably use his land, a rolling easement would not. The main impact of the rolling easement is likely to be the occasional reminders from the land trust or government entity that the land is subject to a rolling easement.
Twenty to forty years before submergence. As time passes and sea level rises, however, the submergence will eventually become close enough at hand to matter to an owner. Different owners (and potential owners) will have different time horizons, expectations, and preferences:
· The current owner of a given home may decide that a growing family requires a much larger house. He may decide to sell rather than enlarge the current home because he wants the house to last for many decades.
· A possible home buyer may consider purchasing this home with plans for a major upgrade to the house to meet his needs for the rest of his life, which he assumes to be about 50 more years. If the home is likely to be submerged in 30–40 years, he may be reluctant to buy it.
· If he does buy the house, he may be reluctant to spend the time and money on the upgrade, knowing he will have to find another home and possibly manage another renovation. If the renovation is likely to pay for itself in resale
· value, he may still go ahead with the expansion and plan to move out 10–15 years later. But for most home addition projects, the costs are not recouped in higher resale values. So even if the property is likely to survive a few more decades, this particular owner is unlikely to pursue the renovation.
· People more likely to purchase this house may include (a) a homebuyer willing to consider a more modest renovation with a shorter payback period, (b) an investor-landlord only interested in short-term modifications that pay for themselves, or (c) a home buyer who is satisfied with the current house.
As time passes, fewer and fewer people will be inclined to add major additions that do not pay for themselves; those who find their homes insufficient will sell to investors or home buyers who are satisfied with the house as it is. The periodic reminders about rolling easements from the land trust or government agency to owners—as well as clear warnings to buyers from realtors—could help ensure that people do not make investments inconsistent with the eventual abandonment of the property. This does not mean that no major renovations will take place—some people have the resources to build a new home likely to be destroyed 10 years hence. But most people with those resources still prefer a home likely to last longer unless they cannot obtain a similar parcel of land without the risk.
Ten to twenty years before submergence. Once submergence is only 10–20 years away, projects that would otherwise be economically justified will start becoming difficult to justify because of the reduced time for recouping an investment. Therefore, relatively few people are likely to buy homes with the intention of making major modifications. Most new purchasers are likely to be investors intending to rent the property or people satisfied with the home as it. Regular maintenance and repairs, including re-roofing, will still be worthwhile; so the neighborhood need not become blighted.
The final decade. The composition of homes is likely to shift from owner-occupied to rental property. As people die or sell their homes, most homebuyers will not want a home with such a limited lifetime. Investors may be more flexible if there is a profitable opportunity: In resort areas, rentals are generally weekly or seasonal. Few people base a decision to rent a particular house on whether they can return the following year. Even in non-resort areas, leases longer than one year are rare for homes. Therefore, the property value to a landlord-investor should only decline as the present value of future rents declines.
The possibility of blight could be serious if an entire neighborhood is expected to be submerged within a decade. Re-roofing may give way to spot repairs; new wiring, new plumbing, and new windows or doors are all less likely. Even painting may seem like a low priority. The increasing preponderance of rental property could further discourage upkeep. In beach resorts, however, where shore erosion rather than inundation threatens homes, the risk of blight will be less. If a row of homes is lost each decade, for example, there will be a mixture of homes whose loss is imminent next to homes that are about to become waterfront, next to homes that are not threatened for a few decades. The high premiums associated with oceanfront property provide an incentive for landowners to maintain their homes until the end.
 Conservation easements are a form of risk management. They are often obtained in areas where there is no certainty that the land would otherwise be developed, because landowners who are certain that they want to develop the land do not to donate such easements. Either sea level rise or development could prove to be less than indicated by the best available projections.
 See, e.g., Tex. Nat. Res. Code Ann. § 61.025 (requiring a warning to all purchasers of coastal property that shore erosion may move the public beach to where the house is now, in which case the state of Texas may force the buyer to remove the house and pay for that removal); and S.C. Code Ann. § 48-39-330 (requiring disclosure to purchasers of property seaward of the setback line that they may be affected by the setback line). Often warnings come at the end of the process of searching for a home, by which time a buyer may already feel committed to buying the home, and disregard the warning.
This page contains a section from: James G. Titus, Rolling Easements, U.S. Environmental Protection Agency. EPA‑430‑R‑11‑001 (2011). The report was originally published by EPA's Climate Ready Estuary Program in June 2011. The full report (PDF, 176 pp., 7 MB) is also available from the EPA web site.
For additional reports focused on the implications of rising sea level, go to Sea Level Rise Reports.