|
>>
>>
Polar Ice-Caps & Sea-Level Rise
Sea Level Rise MapsU.S. Environmental Protection Agency
Sea Level Rise ReportsU.S. Environmental Protection Agency These pages from the EPA provide a number of reports summarizing governmental and academic research on sea-level rise due to climate change, including maps of predicted coastline changes.
Sea Surface Height VisualizationsGoddard Institute for Space Studies
0-6 m Sea Level Rise Maps by RegionCenter for Remote Sensing of Ice Sheets – U.K.
Animated impacts of sea-level rise on U.S. coastal citiesNational Environmental Trust Most estimates of global warming related sea-level rise for the coming century are on the order of 0.3 to 0.7 meters. Many people find it difficult to believe that sea-level changes this small could be as damaging as experts believe they will be (a fact that global warming skeptics gleefully capitalize on in their editorials and publicity campaigns). The confusions stems from the fact that global warming impacts manifest themselves as increases in global average sea-level—which is very different from regional sea-level change, particularly in coastal areas and during storm surges. In fact, sea-level change is a complicated process involving thermal expansion due to local temperature, localized gravitational effects, regional ice and water mass balance, and even local atmospheric pressure. These pages provide animations of the evolution of regional sea-level over time (in Quicktime and/or Windows Media formats). The first is the GISS Scientific Visualization Studio sea-level map page which provides a number of animations of sea surface height anomalies over periods of one to two years as measured by the TOPEX/Poseidon satellite and other satellite-based and model products. Variations shown range from +/- 0.3m to +/- 0.5m depending on the clip. The second shows static images and animations of costal inundation areas by region for sea-level increases of 1m to 6m. The final page from the National Environmental Trust provides animated inundations for a number of U.S. coastal cities that would result from 0.6m to 0.7m of sea-level rise combined with 100-year and hurricane level storm surges. These videos dramatically illustrate that sea-level change is anything but globally uniform and that small changes in the global average mask large, and potentially very destructive impacts in many populated coastal regions.
North Atlantic OscillationLamont-Doherty Earth Observatory, Columbia University The North Atlantic Oscillation (NAO) is a large scale seesaw in atmospheric mass between a subtropical region high and a polar region low that is the dominant mode of winter climate variability in the North Atlantic and much of Greenland. It fluctuates on time scales that vary from one to several years and accounts for a great deal of regional cooling in these areas that is often cited incorrectly as proof that global warming is not happening. This page from Columbia University’s Lamont-Doherty Earth Observatory gives an overview of the NAO with some very informative graphics of the most salient features in its cycles.
NOAA Hurricane forecasts & the Atlantic Multidecadal OscillationRealClimate This discussion at RealClimate by Thomas Crowley of Duke University’s Earth and Ocean Sciences Division discusses the potential impacts of the Atlantic Multidecadal Oscillation (AMO) on global warming and the recent upsurge in Atlantic tropical cyclone activity. The AMO is a 50-80 year timescale cycle in North Atlantic ocean-atmosphere variability that has been inferred from statistical analyses of observational and proxy climate data, climate model simulations. It is believed by some to describe some of the observed early 20th century (1920s-1930s) high-latitude Northern Hemisphere warming and some, but not all, of the high-latitude warming observed in the late 20th century. In recent years it has garnered much attention because global warming contrarians are now attributing most or all 20th century Northern Hemisphere temperatures to it in an attempt to dismiss global warming as “natural variability”. Data on it is scant, as reliable records span no more than 2 of its cycles. Various theories of it causes have been advanced, but as of this writing there is no solid evidence that it has any real physical basis (see the link below).
Atlantic Hurricane Trends Linked to Climate ChangeMann, ME & KA Emanuel. 2006. EOS, 87, (24), pp. 233 - 244 This article from Mann and Emanuel presents the results of their statistical analysis (One of the most thorough of its kind on this subject) that evaluated the correlations of 20th century climate change with various known natural cycles, including the AMO. They found that when other factors are accounted for, the AMO “signal” reduces to red noise. This shows that it is likely to be a statistical anomaly with little or no physical meaning for climate change. This essentially pulls the plug on contrarian claims that it explains away global warming.
Top
|