-11 — 



o Transfer of snow and ice from land to sea 



Warming can transfer snow and ice from land to sea by 

 melting (if the meltwater runs off into the ocean) or 

 deglaciation (glaciers breaking up or moving more 

 rapidly into the ocean). Sea level will rise as a result 

 if these effects are not offset by trie additional 

 accumulation of snowfall on land. Both of these effects 

 are likely to occur with the warming predicted for the 

 next century. The rate at which they would occur, 

 however, is less certain than that of thermal expansion 

 and may not be proportional to the rate of warming. 

 Deglaciation, in particular, may be a phenomenon in 

 which a threshold exists. Once this threshold is 

 passed, the deglaciation may become a self-reinforcing 

 process, whose timing depends on many things other 

 than the magnitude of the warming. 



Geologic history indicates that these physical mechanisms 



describe the behavior of the earth. During warmer periods in 



earth's history, sea level has been higher than in colder 



periods, varying by over one hundred meters. 



END NOTES TO CHAPTER 2 



1/ Winds, currents, and land subsidence and emergence may 

 cause local sea level to change at rates different from 

 global sea level. For specific applications, the global 

 estimates in this document should be adjusted by comparing 

 historical local and global sea level trends. 



2/ Hansen, James E., A. Lacis, and D. Rind, 1983. "Climatic 

 trends due to increasing greenhouse gases," in Coastal 

 Zone ' 83 , Orville T. Magoon, ed. New York: American 

 Society of Civil Engineers. 3:2796-810. 



3/ Ibid. 



4/ Ibid. 



5/ Charney, Jules, et al., 1979. Carbon Dioxide and Climate: 

 A Scientific Assessment . Washington, D.C.: National 

 Academy of Sciences Press. 



6/ Smagorinsky, J., 1982. Carbon Dioxide and Climate: A 



Second Assessment . Washington, D.C.: National Academy of 

 Sciences Press. 



!_/ World Meteorological Organization, Sept. 1982. WHO Global 

 Ozone Research and Monitoring Project , Report No. 14 and 

 Lacis, A., et al., 1982. "Greennouse effect of trace gases, 

 1970-1980." Geophysical Research Letters . 81:10:1035-8. 



