Cover Image

PAPERBACK
$49.95



View/Hide Left Panel
FIGURE 7.2 Annual, global mean sea level as determined by records of tide gauges (red curve with error bars, from Church and White [2006]; blue curve, from Holgate and Woodworth [2004]) and satellite altimetry (black curve, from Leuliette et al. [2004]). For the last half of the 20th century, the rate of sea level rise can be estimated as being about 0.07 in/yr (1.8 mm/yr), with the most recent decade exhibiting a rate of sea level rise over 0.12 in/yr (3 mm/yr). The red and blue curves show deviations in sea level relative to the 1961 to 1990 period; the black curve shows deviations from the average of the red curve relative to the 1993 to 2001 period. SOURCE: Bindoff et al. (2007).

FIGURE 7.2 Annual, global mean sea level as determined by records of tide gauges (red curve with error bars, from Church and White [2006]; blue curve, from Holgate and Woodworth [2004]) and satellite altimetry (black curve, from Leuliette et al. [2004]). For the last half of the 20th century, the rate of sea level rise can be estimated as being about 0.07 in/yr (1.8 mm/yr), with the most recent decade exhibiting a rate of sea level rise over 0.12 in/yr (3 mm/yr). The red and blue curves show deviations in sea level relative to the 1961 to 1990 period; the black curve shows deviations from the average of the red curve relative to the 1993 to 2001 period. SOURCE: Bindoff et al. (2007).

CAUSES OF SEA LEVEL RISE

Past, present, and future changes in global sea level are mainly caused by two fundamental processes: (1) the thermal expansion of existing water in the world’s ocean basins as it absorbs heat and (2) the addition of water from land-based sources—mainly ice sheets and glaciers, but also other smaller sources. Geological processes (subsidence and uplift), ocean circulation changes, and other processes are important for determining local and regional rates of sea level rise, but the total volume of the world’s oceans—and hence global average sea level—is essentially controlled by thermal expansion and addition of water from land-based sources.

Ocean Thermal Expansion

The ocean is by far the most important heat reservoir in the climate system, with a heat storage capacity more than 1,000 times larger than that of the atmosphere. In



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement