Losses of coastal 
ecosystems and 
ecosystem services 
Groundwater 
salinisation 
Flooding and damages 
to coastal infrastructure
Global sea level rise 
in meters relative to 1900
sea level 
rise by 2100 
depends on 
the emissions 
scenario
this can be chronic high 
tide flooding and extreme 
flooding during storms
likely 
ranges 
of sea 
level rise
very low
low
intermediate
high
very high
low emissions scenario range
very high emissions scenario range
a) Sea level rise: observations and projections 2020-2100, 2150, 2300 (relative to 1900)
Sea level rise will continue for millennia, but how 
fast and how much depends on future emissions
Example: timing of 0.5m sea level rise
2000
2100
2200
2300+
very low
very high
Higher greenhouse gas emissions lead to larger and 
faster sea level rise, demanding earlier and stronger 
responses, and reducing the lifetime of some options
Key
Responding to sea level rise requires long-term planning
b) Typical timescales of coastal risk-management measures
1 billion
people exposed
By 2050:
Extreme sea level events that 
occured once per century will be 
20-30 times more frequent