Captain Sea Levelís Links
How Much is the Sea Rising?
Permanent Service for Mean Sea Level. Data from around the world, and linear regression coefficients that provide a trend. Before drawing conclusions about a location, make sure that the site has more than 40 years, or that there is a nearby site corroborating the trend.
National Ocean Service: Sea Levels Online. If you want to know about the United States, this new site may be more useful than the Permanent Serviceóespecially because of how it is integrated into related information from NOAA.
summarizing worldwide sea level trends.
How Much Will the Sea Rise in the Future?
Intergovernmental Panel on Climate Change (2001): Science of Climate Change . Until 2007, this was the "party line" estimate of global warming and sea level rise by the year 2100. The more recent IPCC (2007) report split the issue of sea level rise into three chapters, which impaired the quality in some ways. Caution: The analysis was not designed for coastal planning purposes but rather to indicate consequences of greenhouse gases.
US Comments on IPCC. IPCCís projections failed to include all of the possible contributions from Antarctica. In addition, the report should have provided results in a format more amenable to making local projections and reconciled model-data inconsistencies. Example: all IPCC models project acceleration of sea level rise, but the low projection is less than the historic trend. How can that be? (Note: Department of State pulled these comments off their web page--I'll try to post when I can find them).
The Probability of Sea Level Rise. This is the first probabilistic assessment of global warming and sea level rise from greenhouse gases. This report was designed for coastal planning. Therefore it includes a chapter on local projections that reconciles the models with data. Unlike IPCC, all scenarios based on models that project acceleration show the sea rising more rapidly in the future than the past. The probabilities provide useful "worst-case" scenarios, and also quantify "worse-case" scenarios with 5 and 10% probabilities.
recent paper on the subject by Tom Wigley . During the 1990s,
his models were the backbone of the IPCC science assessments. He still is often
ahead of the curve. A reasonable practitioner will always find out how his
projections compare with the most recent IPCC assessment. He usually reports
results in a fashion that allows ready comparison. The Captain uses his analysis
to consider the most likely rise in sea level, but not the worse-case or
worst-case scenario. See his 2002 explanation
The most recent paper on the subject by Jim Hansen. The Captainís candidate for the next Nobel Prize awarded for climate change research. Although he helped EPA get started in assessing the consequences of sea level rise in 1983, he moved on to other issues. But twenty years later he came back to this issue, with a provocative essay in Climatic Change warning that greenhouse gases may put polar glaciers on a "slippery slope to Hell." The Captain uses these analyses to consider worse-case scenarios. (This looks like an impermanent link so if it moves, search for "slippery slope", James Hansen, and "sea level rise". )
Have we Overstated or Oversimplified the Problem?
World Climate Report often explains why most of what EPA and IPCC have written is probably wrong. Most of their material is useful background, articulated in a thoughtful way. It includes a few cheap shots about other people's views, but given the publisher's mission, it probably would not be able to keep readership or funding without a few jabs at EPA and IPCC. Too bad the authors didn't call me: I could have given them citations of foolish things that really happened!
EPA's mea culpa for having over-estimated future sea level rise during the 1980s. Included in Chapter 8 of the Probability of Sea Level Rise.
The Sky Isn't Falling and the Sea Isn't Rising. A Classic by Fred Singer.
Don't Cry for Them: The Maldives' Islands are OK. Nils-Axel MŲrner and Michael Tooley team up to challenge the view that sea level is rising relative to this atoll nation. Too bad the British didn't install a tide gauge when they established the naval base at Gan. This paper seems to have disappeared, perhaps because of the tsunami that hit the Maldives shortly after the paper was posted online. If you can find a copy, please send it to me. The peer-reviewed paper is still available. For another view, see a 1989 paper recommending that the Maldives should elevate their populated islands and a speech about sea level rise to the United Nations by then-President Gayoom. One option for tsunami relief is Friends of Maldives.
What land will be inundated?
Published Benchmark Sheets. My deck hands wonít even go to this site until Iíve asked them thrice. But my engineer understands that (with the exception of some unpublished EPA sea level rise maps) the elevations you see on most maps are not relative to sea level. For example, the 5-foot contour is not 5 feet above sea level; it is 5 feet above a "benchmark", such as National Geodetic Vertical Datum of 1929, or the North Atlantic Vertical Datum of 1988. How high is sea level compared to the benchmark? Go to this site and find out. The Captain recommends that you always consider how high the land is relative to spring high water (the average full moon tide) .
Topozone. Virtually all of the USGS 1:24,000 maps are available for checking our elevations. You are of course subject to the limitations of the contour interval USGS used. For sea level rise purposes, I stick to the Atlantic Coast from Connecticut South, and the Gulf of Mexico. The 1:100,000 and 1:250,000 maps are good for getting your bearing. You are limited to the contours USGS used, which occasionally makes no sense (e.g. 20-foot contours in Kent Island, Maryland and Horry County, South Carolina). Soon LIDAR-based maps will change all that, but today one usually has to download the data and make her own map. Unfortunately, this service stopped being free in 2008, but the annual cost is less than a cab ride to the nearest USGS map store.
Terraserver: This site has the same maps as Topozone, but gives you less control over which map-scale you are examining when you alter the screen scale. On the other hand, it does have aerial photographs, and it was free last I checked.
Elevation maps from EPA. These maps give one a sense of nationwide
vulnerability. If you have an 11 X 17" printer, I recommend the map
that has the entire eastern half of the United States. But the maps
only have 1.5- and 3.5-meter contours, and elevations are relative to
the National Geodetic Vertical Datum, not sea level. EPA
is attempting to remedy this situation in its next
generation of maps. Some of those sea
level rise maps can be found in chapter 1 and the appendices of a draft
report by the U.S. Climate Change
County Elevation Maps from EPA.
These maps give one a sense the vulnerability of specific counties in eight mid-Atlantic states and the District of Columbia. Statewide and
regional maps are also available. Some of the maps are in the technical paper on the EPA web site; others
can be found in a draft report by the U.S. Climate Change Research Program. The entire set of sea level rise maps is on
the "More Sea Level Rise Maps" website.
Level Rise Reports
More Sea Level
Sea Level's Christmas Song: When the North Pole Melts