Rising Sea Levels: Potential Impacts and
Responses
RO BERT J. NICHOLLS
1. Introduction
Global-mean sea levels are expected to rise through the 21st century and beyond
due to human-induced global warming. Given the large population in the coastal
zone, these changes have important long-term implications for societal use of the
coastal zone. Figure 1 suggests that about 20 and 37% of global population live
within 30 and 100 km from the coast, respectively (see caveats of Small et al.). A
considerable portion of global GDP is also produced in coastal zones. In
addition, it is widely reported that many coastal locations are experiencing
population and GDP growth that is higher than their national averages, and
there is a significant urbanizing trend. This suggests a net coastward migration
of people and economic activities. Thus, human exposure to the effects of sea-level
rise and climate change is growing rapidly.
Coastal areas are already threatened by a range of coastal hazards such as
erosion, saline intrusion, flooding and tsunamis: all will be exacerbated by
sea-level rise. Additionally, human activity is producing profound changes to
the world’s coastal zone such as reducing freshwater inputs, modifying sediment
budgets, armouring the coast and direct and indirect ecosystem destruction.
Therefore, climate change and sea-level rise are an additional pressure on
C. Small, V. Gornitz and J. Cohen, Coastal hazards and the global distribution of human
population, Environ. Geosci., 2000, 7, 3—12.
R. K. Turner, S. Subak and W. N. Adger, Pressures, trends, and impacts in coastal zones:
interactions between socioeconomic and natural systems. Environ. Manage., 1996, 20(2), 159—173.
J. D. Sachs, A. D. Mellinger and J. L. Gallup, The geography of poverty and wealth, Sci. Am., 2001,
284(3), 70—75.
WCC’93, Preparing to Meet the Coastal Challenges of the 21st Century. Report of the World Coast
Conference, Noordwijk, The Netherlands, 1—5 November 1993, Ministry of Transport, Public
Works and Water Management, The Hague, The Netherlands, 1994, 49s pp. ; apps.
R. Hausmann, 2001, Prisoners of geography, Foreign Policy, 2001, No 122 (January/February), 45—53.
R. J. Nicholls, Coastal megacities and climate change, Geojournal, 1995, 37, 369—379.
P. Holligan and H. deBoois (eds.), Land-Ocean Interactions in the Coastal Zone (LOICZ). Science
Plan. International Geosphere Biosphere Programme, International Council of Scientific Unions,
Stockholm, 1993, 50 pp.
Issues in Environmental Science and Technology, No. 17
Global Environmental Change
© The Royal Society of Chemistry, 2002
83
Responses
RO BERT J. NICHOLLS
1. Introduction
Global-mean sea levels are expected to rise through the 21st century and beyond
due to human-induced global warming. Given the large population in the coastal
zone, these changes have important long-term implications for societal use of the
coastal zone. Figure 1 suggests that about 20 and 37% of global population live
within 30 and 100 km from the coast, respectively (see caveats of Small et al.). A
considerable portion of global GDP is also produced in coastal zones. In
addition, it is widely reported that many coastal locations are experiencing
population and GDP growth that is higher than their national averages, and
there is a significant urbanizing trend. This suggests a net coastward migration
of people and economic activities. Thus, human exposure to the effects of sea-level
rise and climate change is growing rapidly.
Coastal areas are already threatened by a range of coastal hazards such as
erosion, saline intrusion, flooding and tsunamis: all will be exacerbated by
sea-level rise. Additionally, human activity is producing profound changes to
the world’s coastal zone such as reducing freshwater inputs, modifying sediment
budgets, armouring the coast and direct and indirect ecosystem destruction.
Therefore, climate change and sea-level rise are an additional pressure on
C. Small, V. Gornitz and J. Cohen, Coastal hazards and the global distribution of human
population, Environ. Geosci., 2000, 7, 3—12.
R. K. Turner, S. Subak and W. N. Adger, Pressures, trends, and impacts in coastal zones:
interactions between socioeconomic and natural systems. Environ. Manage., 1996, 20(2), 159—173.
J. D. Sachs, A. D. Mellinger and J. L. Gallup, The geography of poverty and wealth, Sci. Am., 2001,
284(3), 70—75.
WCC’93, Preparing to Meet the Coastal Challenges of the 21st Century. Report of the World Coast
Conference, Noordwijk, The Netherlands, 1—5 November 1993, Ministry of Transport, Public
Works and Water Management, The Hague, The Netherlands, 1994, 49s pp. ; apps.
R. Hausmann, 2001, Prisoners of geography, Foreign Policy, 2001, No 122 (January/February), 45—53.
R. J. Nicholls, Coastal megacities and climate change, Geojournal, 1995, 37, 369—379.
P. Holligan and H. deBoois (eds.), Land-Ocean Interactions in the Coastal Zone (LOICZ). Science
Plan. International Geosphere Biosphere Programme, International Council of Scientific Unions,
Stockholm, 1993, 50 pp.
Issues in Environmental Science and Technology, No. 17
Global Environmental Change
© The Royal Society of Chemistry, 2002
83