areas or the costs of water management and drainage. Therefore, they are more
useful as a relative cost rather than an absolute adaptation cost. Given the
potentially serious flood impacts described above and the long-term trend of
expanding economies, the relative magnitude of these protection costs suggests
that protection is likely to be more widely feasible than the current situation
would suggest (see also Fankhauser). The appropriateness of such protection is
another question.
Coastal wetlands are already declining at 1%/year due to indirect and direct
human activities. Wetland losses given a 1 m rise in sea level could approach
46% of the present stock. Taking a 38 cm global scenario by the 2080s, between
6% and 22% of the world’s wetlands could be lost due to sea-level rise. When
added to existing trends of indirect and direct human destruction, the net effect
could be the loss of 36—70% of the world’s coastal wetlands, or an area of up to
210 000 km. Therefore, sea-level rise is a significant additional stress that
worsens the prognosis for wetlands. Regional losses would be most severe on the
Atlantic coast of North and Central America, the Caribbean, the Mediterranean
and the Baltic. While there are no data, by implication, all small island regions are
also threatened due to their low tidal range.
Nearly 10% of global rice production is located in coastal areas in South,
South-East and East Asia that are vulnerable to sea-level rise. Based on a 1 m rise
scenario, this rice production could fall significantly, especially the large deltas of
Bangladesh, Myanmar (Burma) and Vietnam, unless there was substantial
adaptation. Presently, the production from these areas feeds 200 million people.
In conclusion, these studies suggest that sea-level rise could produce important
impacts on people (via flooding and food supply) and coastal ecosystems.
National reviews show a similar picture. Therefore, some response appears
prudent.
4 Responding to Sea-level Rise
Given the high impact potential already discussed and the commitment to
sea-level rise independent of emission scenarios, a rational response to sea-level
rise and climate change in coastal areas would be to identify the most appropriate
mixture of mitigation and adaptation. Mitigation could greatly reduce the
risks associated with sea-level rise and climate change beyond the 21st century.
Adaptation acts to reduce the impacts of sea-level rise and climate change, as well
S. Fankhauser, Protection versus retreat: estimating the costs of sea-level rise, Environ. Planning A,
1995, 27, 299—319.
R. J. Nicholls, Synthesis of vulnerability analysis studies, Proceedings of WORLD COAST 1993,
Ministry of Transport, Public Works and Water Management, the Netherlands, 1995, pp.
181—216 (downloadable at http//www.survas.mdx.ac.uk/).
R. J. Nicholls and N. Mimura, Regional issues raised by sea-level rise and their policy implications,
Clim. Res., 1998, 11 (1), 5—18.
M. Parry, N. Arnell, M. Hulme, R. Nicholls and M. Livermore, Adapting to the inevitable, Nature,
1998, 395, 741.
M. Parry, N. Arnell, T. McMichael, R. Nicholls, P. Martens, S. Kovats, M. Livermore, C.
Rosenzweig, A. Iglesias and G. Fischer, Millions at risk: defining critical climate threats and
targets, Global Environ. Change, in press.
R. J. Nicholls
100
useful as a relative cost rather than an absolute adaptation cost. Given the
potentially serious flood impacts described above and the long-term trend of
expanding economies, the relative magnitude of these protection costs suggests
that protection is likely to be more widely feasible than the current situation
would suggest (see also Fankhauser). The appropriateness of such protection is
another question.
Coastal wetlands are already declining at 1%/year due to indirect and direct
human activities. Wetland losses given a 1 m rise in sea level could approach
46% of the present stock. Taking a 38 cm global scenario by the 2080s, between
6% and 22% of the world’s wetlands could be lost due to sea-level rise. When
added to existing trends of indirect and direct human destruction, the net effect
could be the loss of 36—70% of the world’s coastal wetlands, or an area of up to
210 000 km. Therefore, sea-level rise is a significant additional stress that
worsens the prognosis for wetlands. Regional losses would be most severe on the
Atlantic coast of North and Central America, the Caribbean, the Mediterranean
and the Baltic. While there are no data, by implication, all small island regions are
also threatened due to their low tidal range.
Nearly 10% of global rice production is located in coastal areas in South,
South-East and East Asia that are vulnerable to sea-level rise. Based on a 1 m rise
scenario, this rice production could fall significantly, especially the large deltas of
Bangladesh, Myanmar (Burma) and Vietnam, unless there was substantial
adaptation. Presently, the production from these areas feeds 200 million people.
In conclusion, these studies suggest that sea-level rise could produce important
impacts on people (via flooding and food supply) and coastal ecosystems.
National reviews show a similar picture. Therefore, some response appears
prudent.
4 Responding to Sea-level Rise
Given the high impact potential already discussed and the commitment to
sea-level rise independent of emission scenarios, a rational response to sea-level
rise and climate change in coastal areas would be to identify the most appropriate
mixture of mitigation and adaptation. Mitigation could greatly reduce the
risks associated with sea-level rise and climate change beyond the 21st century.
Adaptation acts to reduce the impacts of sea-level rise and climate change, as well
S. Fankhauser, Protection versus retreat: estimating the costs of sea-level rise, Environ. Planning A,
1995, 27, 299—319.
R. J. Nicholls, Synthesis of vulnerability analysis studies, Proceedings of WORLD COAST 1993,
Ministry of Transport, Public Works and Water Management, the Netherlands, 1995, pp.
181—216 (downloadable at http//www.survas.mdx.ac.uk/).
R. J. Nicholls and N. Mimura, Regional issues raised by sea-level rise and their policy implications,
Clim. Res., 1998, 11 (1), 5—18.
M. Parry, N. Arnell, M. Hulme, R. Nicholls and M. Livermore, Adapting to the inevitable, Nature,
1998, 395, 741.
M. Parry, N. Arnell, T. McMichael, R. Nicholls, P. Martens, S. Kovats, M. Livermore, C.
Rosenzweig, A. Iglesias and G. Fischer, Millions at risk: defining critical climate threats and
targets, Global Environ. Change, in press.
R. J. Nicholls
100