US Climate Change Science Program

I recently read the US Climate Change Science Program's report "Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region." Released in January, 2009, this is part of the US Govt's documents that address the public policy issues surrounding climate change and its effects. Find more information at GlobalChange.gov.


This report has some interesting bits of information for engineers to consider:

Consensus in the climate science community is that the global climate is changing, mostly due to mankind’s increased emissions of greenhouse gases such as carbon dioxide, methane, and nitrous oxide, from burning of fossil fuels and land-use change (measurements show a 25 percent increase in the last century). Warming of the climate system is unequivocal. [my emphasis added]

...there is currently no consensus on the upper bound of global sea-level rise...

Recent studies suggest the potential for a meter or more of global sea level rise by the year 2100, and possibly several meters within the next several centuries.

...the rate of rise appears to have accelerated over twentieth century rates, possibly due to atmospheric warming causing expansion of ocean water and ice-sheet melting...

With a substantial acceleration of sea-level rise, traditional coastal engineering may not be economically or environmentally sustainable in some areas.

...it is likely that most wetlands will not survive acceleration in sea-level rise by 7 millimeters per year. Wetlands may expand inland where low-lying land is available but, if existing wetlands cannot keep pace with sealevel rise, the result will be an overall loss of wetland area in the Mid-Atlantic. The loss of associated wetland ecosystem functions (e.g., providing flood control, acting as a storm surge buffer, protecting water quality, and serving as a nursery area) can have important societal consequences, such as was seen with the storm surge impacts associated with Hurricanes Katrina and Rita in southern Louisiana, including New Orleans, in 2005.

Loss of tidal marshes would seriously threaten coastal ecosystems, causing fish and birds to move or produce fewer offspring. Many estuarine beaches may also be lost, threatening numerous species.

Nearly one-half of the 6.7 billion people around the world live near the coast and are highly vulnerable to storms and sea-level rise.

Nationally, most current coastal policies do not accommodate accelerations in sea-level rise.

Most coastal regions are currently managed under the premise that sea-level rise is not significant and that shorelines are static or can be fixed in place by engineering structures. The new reality of sea-level rise due to climate change requires new considerations in managing areas to protect resources and reduce risk to humans.

This is scary stuff. If we underestimate the potential for climate change even a small amount, then it is unlikely that engineers can help. Typically engineers err on the side of caution. We are a conservative bunch, and uncertainty is explicitly and implicitly managed through the standard use of Load and Resistance Factors. However, the vast majority of civil engineers in the US are still not convinced of climate change at this point.

And while most people feel that governments are working towards a solution, the truth is that almost all governments have decided to sacrifice coastal areas to avoid the political reality of reducing emissions to really safe levels. Most governments have decided to "limit" global warming by redefining "safe levels" to whatever level is politically convenient.

I guess we are all counting on "geoengineering" to save the day, but that is probably the most expensive and least satisfactory solution of all (see Real Climate entry for more information). For those wondering just what Coastal Engineering can do for us, see my earlier post about San Francisco or just look at the multi-billion dollar MOSE Project being built to protect Venice.


Neither Coastal Engineering nor Geoengineering will be our savior. The cure of Geoengineering is almost as bad as the disease. Coastal Engineering is an expensive solution that requires us to choose certain areas for preservation. What is likely is that some areas are selected as too important to cede. The remainder will probably be lost because of rapid changes in sea level. The consequences of this change will be severe. Wetlands that shelter endangered bird species and protect coastal areas from hurricane storm surge will be lost.

The receding shoreline begins shifting so rapidly that whole towns must be abandoned or moved once per decade. The beautiful fishing villages and beaches of the Northeast will be decimated. The debate over Galveston and New Orleans becomes a moot point, as we slowly watch the Strand and Bourbon Street become modern versions of Atlantis.

So the next time you see a cost-benefit argument against the Waxman-Markey bill (such as "Time for Inaction on Global Warming" published in the WSJ), or a video from the American Petroleum Institute warning about job losses, try to remember that the cost of inaction is probably higher than represented. An ounce of prevention is worth a pound of cure.