2. What is sea level ?
The level of the sea's surface, used in reckoning the height of geographical
features such as hills and as a barometric standard.
What is Mean sea level ?
Mean sea level (MSL) is an average level of
the surface of one or more of Earth's oceans
from which heights such as elevations may
be measured
MODEL OF SHAPE OF EARTH
What is Sea level rise ?
A sea level rise is an increase in global mean sea level as a result of
an increase in the volume of water in the world’s oceans.
3. Causes of Sea level rise
• Ocean warming (thermal expansion)
• Eustasy
• Isostasy
• Melting of Glaciers & Ice sheets
• Decline in water storage on land
• Ice loss from Greenland and West Antarctica
• Global warming
4. Causes of Sea level rise
Ocean warming (thermal expansion)
Global warming not only causes the temperature on land to increase,
but also leads to an increase in sea water warming. This warming
started mainly during the industrial evolution, and intensified when more
and more trees were being cut down. Thermal expansion also affects
the movement of hot and cold oceanic currents around the globe, and
even a slight shift in the direction and temperature of any major current
can have large-scale effects, especially on the sea level rise. Due to
this, the water expands and its volume increases. This leads to a
periodic rise in sea levels.
TEMPERATURE CHANGES IN OCEAN
5. Causes of Sea level rise
Eustas
y
Any uniformly global change of sea level that may reflect a
change in the quantity of water in the ocean, or a change in the
shape and capacity of the ocean basins that results in change
in sea level.
Isostas
yChanges in Earth’s geology. The tectonic plates of the Earth
are moving in a slow pace constantly. This changes the
structure of the Earth and increases or decreases the height of
land above and below sea level.
6. Causes of Sea level rise
Melting of Glaciers & Ice sheets
Large ice formations, like glaciers and the polar ice caps,
naturally melt back a bit each summer. In the winter, snows,
primarily from evaporated seawater, are generally sufficient to
balance out the melting. Recently, though, persistently higher
temperatures caused by global warming have led to greater-
than-average summer melting as well as diminished snowfall
due to later winters and earlier springs. This imbalance results
in a significant net gain in the ratio of runoff to ocean
evaporation, causing sea levels to rise.
7. Causes of Sea level rise
Ice loss from Greenland and West Antarctica
As with the glaciers and ice caps, increased heat is
causing the massive ice sheets that cover Greenland and
Antarctica to melt at an accelerated pace. Scientists also
believe meltwater from above and seawater from below is
seeping beneath Greenland's and West Antarctica's ice
sheets, effectively lubricating ice streams and causing
them to move more quickly into the sea. Higher sea
temperatures are causing the massive ice shelves that
extend out from Antarctica to melt from below, weaken,
and break off.
10. Impacts of Sea level rise
• Wet land loss
• Coastal erosion
• Salt water intrusion
• Loss of habitats of fish,birds & plants
• Contamination of agricultural soil
• Loss of mangroves & coral reefs
• Loss of low lying lands
• Powerful storm surges
Ecological
imbalance
12. IPCC FRAME WORK
The IPCC(Intergovernmental Panel on Climate Change) adopted a work plan for adaptive
responses & strategies based on data regarding environmental, economic, social, cultural,
legal, institutional and financial implications.
• identify coastal areas, populations and resources at risk
• develop global and regional research and monitoring systems
• develop public awareness of risks to coastal resources
• encourage integrated coastal area and resource management
• use country-specific studies to evaluate available adaptive options
• develop techniques for mitigation through cost effective approaches for adaptation
• adopt a framework convention on climate change to facilitate cooperative efforts to limit
and/or adapt to climate change
14. • Planting and maintaining mangroves is considered as a
potential natural mitigation measure against this
problem. Mangroves reduce the intensity of waves
crashing on the shoreline and also help in reducing the
associated impact in case of sea level rise.
Mitigation Measures | ADAPTION STRATEGIES
Strategy Features Methods Site Advantages
Protection
(Defense)
Dikes
Levees
Sea Walls
Groins
Build physical
barriers to block
water
For hard-to-move
facilities and
infrastructure on flat
ground
Mangroves
Wetlands Sand
dunes Tidal Flats
Create buffer with
vegetation or landforms
For maintaining
shoreline at sites with
existing coastal forest
or sand dunes
| PROTECTION
Pre implementation implementation Post implementation Pre implementation implementation Post implementation
15. Mitigation Measures | ADAPTION STRATEGIES| ACCOMODATION
Strategy Features Methods Site Advantages
Accommodation Raising level
Desalination
Drainage
Alarm system
Upgrade
functions while
maintaining
location
For redevelopment projects or
facilities at sites without high
ground nearby
Pre implementation implementation Post implementation
16. Mitigation Measures | ADAPTION STRATEGIES| RETREAT
Strategy Features Methods Site Advantages
Retreat Relocation
Abandonment
Relocate
facilities to low-
risk uplands
For residential and public facilities
at sites with low-risk uplands
nearby
Pre implementation implementation Post implementation
17. Mitigation Measures | ADAPTION STRATEGIES| ATTACK
Strategy Features Methods Site Advantages
Attack Land Reclamation
Piers Ports
Harbors
Extend facilities
towards water
For facilities requiring direct access
to water
Pre implementation implementation Post implementation
18. Mitigation Measures
• Temporary installation of porous rock structures on the shores, and construction of buildings
on elevated land can help minimize the damage caused by potential sea level rise. The
advantage of elevation is very important, especially in low-lying regions, if sea levels are
increasing steadily.
• The most important and long-term mitigation measure is to reduce our carbon footprint, and
reduce the harmful emissions, which are damaging the environment on land, in the oceans,
and the atmosphere. If global warming can somehow be decreased substantially, then the sea
level rise can also be minimized and controlled.
• Building tall walls and similar structures might help reduce sea water intrusion up to a certain
level, but this solution is of no help when the sea level rises drastically and even during
tsunamis striking the coastal regions.
• Constructing levees might help on a small scale, especially if the particular coastal region
experiences less increase in ocean water over a longer period of time.
