CONCLUSIONS 



It has often been assumed in past writings that changes in sea level are too slow 

 and imperceptible to play a significant role in shoreline changes on time scales of 

 concern to human development. This paper has demonstrated that, contrary to this 

 belief, sea level is likely to rise at a fast and accelerating pace in the very near future. 



Now, local relative sea-level changes along the Louisiana coast appear to be 

 dominated by subsidence. The rate of subsidence is more than five times as high as the 

 average rate of eustatic sea-level rise for the last century. Eustatic sea level is directly 

 controlled by global mean temperature through changes in the specific volume of near- 

 surface water and melting of polar ice sheets. The global mean temperature, in turn, is 

 affected by periodic natural climatic cycles and a C02-induced "greenhouse effect". 

 Using conservative estimates for the rate of CO2 release, one finds that the global 

 warming over the next decades may cause a eustatic sea level rise of about I cm/yr 

 between the years 1980 and 2020. This rate exceeds the local subsidence rate of coastal 

 Louisiana implying that global eustatic sea-level changes will be our greatest concern in 

 the next few decades. 



The estimated eustatic rise plus subsidence may amount to about a 75-cm local 

 relative sea-level rise over the next 40 years along the Louisiana coast. With that rate 

 of rise, it is imperative that plans for development and protection of the Louisiana coast 

 take sea-level changes into account. 



LITERATURE CITED 



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