Transcript 1.3-Drivers-Impacts-Coastal-Resources-2012-07-12

COASTAL RESOURCES
CGE TRAINING MATERIALS FOR VULNERABILITY AND ADAPTATION
ASSESSMENT
Expectation from the Training Material
• After having read this Presentation, in combination with the related
handbook, the reader should:
•
Identify the drivers and potential impacts of climate change
on coastal zones;
•
Have an overview of the methodological approaches, tools
and data available to assess the impact of climate change on
coastal zones;
•
Identify appropriate adaptation measures.
2
1.3 (I) Climate Change and Coastal Resources
 Coastal resources will be affected by a number of consequences of climate change,
including:
 Higher sea levels
 Higher sea temperatures, sea-surface temperature,
 El Niño/La Niña-Southern Oscillation (ENSO) events/climate cycle
 Changes in precipitation patterns and coastal runoff
 Changes in storm tracks, frequencies, and intensities, and
 Other factors like Wave climate, Storminess, Land subsidence etc.
Coastal Climate Change Drivers
Primary drivers of coastal climate change impacts, secondary drivers
and processes (adapted from NCCOE, 2004)
Primary driver
Secondary or process variable
Mean Sea Level
 Local sea level
Ocean currents, temperature and
acidification
 Local currents
 Local winds
Wind climate
 Local waves
Rainfall/runoff
 Groundwater
Some Climate Change Factors
Net extreme
event
hazards
Net regional
mean sea
level rise
Timeframe
Cause
Predictability
Recurring
extremes (Storm
surge/tide)
Hour-days
Wave, wind,
storms
Moderate to
uncertain
Tide ranges
Daily-yearly
Gravitational
cycle
Predictable
Regional sea level
variability
Seasonaldecadal
Wave climate,
ENSO, PDO
Moderate;
Not well known
Regional net land
movement
DecadesMillennia
Tectonic
Predictable once
measured
Regional SLR
Monthsdecades
Ocean warm/
current/climate
Observable;
future uncertain
Global mean SLR
Decadescentauries
Climate
change (temp,
ice melt)
Short term
understandable;
future uncertain
Potential Impacts
Climate Change: Air Temperature
- Global Context
1900-2000: Global mean- surface air temp
increased by 0.6 0C
Projected increase (1990-2100): 1.4 – 5.80C
(Based on greenhouse gas emission)
2030: + 0.7 in monsoon,+ 1.3 in winter
2050: + 1.1, + 1.8 in 2050.
Current Global Predictions of Sea Level Rise
 Conclusions about future sea-level rise in the IPCC’s Third Assessment Report (TAR,
2001) and Fourth Assessment Report (AR4, 2007) were broadly similar.
 The IPCC AR4 projections estimated global sea-level rise of up to 79 centimeters by
2100, noting the risk that the contribution of ice sheets to sea level this century could be
higher
Post AR4
 Research since AR4 has suggested that dynamic processes, particularly the loss
of shelf ice that buttresses outlet glaciers, can lead to more rapid loss of ice than
melting of the top surface ice alone.
 There is growing consensus in the science community that sea-level rise at the
upper end of the IPCC estimates is plausible by the end of this century, and that
a rise of more than 1.0 metre and as high as 1.5 metres cannot be ruled out.
Post AR4
Source: Church et al, 2008
Projected Global Average Surface and Sea Level Rise at the end
of 21st Century (Source: IPCC, 2007a) (Summary)
Temperature Change
(0C at 2090-99 relative to 1980-99)a
Sea level rise
(m at 2090-99 relative to 1980-99)
Case
Best
estimate
Likely
range
Model-based range excluding future rapid
dynamical changes in ice flow
Year 2000
concentration b
0.6
0.3-0.9
NA
B1 scenario
1.8
1.1-2.9
0.18-0.38
B2 scenario
2.4
1.4-3.8
0.20-0.45
A1T scenario
2.4
1.4-3.8
0.20-0.43
A1B scenario
2.8
1.7-4.4
0.21-0.48
A2 scenario
3.4
2.0-5.4
0.23-0.51
A1F1 scenario
4.0
2.4-6.4
0.26-0.59
Notes: aThese estimates are assessed from a hierarchy of models that encompass a
simple climate model, several Earth System Models of Intermediate Complexity, and a
large number of Atmosphere-Ocean General Circulation Models (AOGCMs).
bYear 2000 constant composition is derived from AOGCMs only.
IPCC AR4 is missing the
rapid ice flow changes….
“…an improved estimate of the range of SLR to 2100 including
increased ice dynamics lies between 0.8 and 2.0 m.”
Recent findings
~1 m
Considering the dynamic effect of ice-melt contribution to global sea level
rise, Vermeer and Rahmstorf (2009) estimated that by 2100 the sea level
rise would be approximately three times as much as projected (excluding
rapid ice flow dynamics) by the IPCC-AR4 assessment.
Even for the lowest emission scenario (B1), sea level rise is then likely to
be about 1 m and may even come closer to 2 m.
http://www.msnbc.msn.com/id/42878011/ns/us_newsenvironment
Climate Change: El Niño/ La Niña -Southern Oscillation (ENSO)
Global context
(Warm SST)
Develops in JAS, strengthen through OND, and
weakens in JFM
lowP
 El Niño—major warming of the equatorial
waters in the Pacific Ocean


The anomaly of the SST in the tropical Pacific
increases (+0.5 to +1.5 deg. C in NINO 3.4 area)
from its long-term average;
A high pressure region is formed in the western
Pacific and low-pressure region is formed in
the eastern Pacific —this produces a negative
ENSO index (SOI negative).
 La Niña—major cooling of the equatorial
waters in the Pacific Ocean

H(Cold SST)
low

The anomaly of the SST in the tropical Pacific
decreases (-0.5 to -1.5 deg. C in NINO 3.4 area)
from its long-term average;
A high pressure region is formed in the eastern
Pacific and low-pressure region is formed in
the western Pacific—this produces a positive
ENSO index (SOI positive).
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La Niña (strengthened trade winds)
La Niña, El Niño
(Cold SST) high
pressure
system
(Warm SST) low
pressure
system
El Niño (weakened trade winds)
SA
H
NINO 3.4
B
A
G
NWP
Nino 4
M
Nino 3
SP
A
S
W
E
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El Niño, La Niña, SST, and the Nino Region
El Nino is a major warming of the equatorial waters in the Pacific
Ocean. It usually occurs every 3 to 7 years
 NINO1+2 (0-10S, 80-90W)
 Warms first when an El Niño event develops
 NINO3 (5S-5N; 150W-90W)
 Has the largest variability in SST on El Niño time scales
 NINO3.4 (5S-5N; 170W-120W)
 Has large variability on El Niño time scales, and that is closer (than NINO3) to the region
where changes in local SST are important for shifting the large region of rainfall typically
located in the far western Pacific.
 NINO4 (5S-5N: 160E-150W)
 Changes of SST lead to total values around 27.5C, which is thought to be an important
threshold in producing rainfall
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Sea Level Change during EL Niño Year
+ 24”
- 12”
El Niño/ La Niña Years (1950-2012)
The numbers of El Niño/
La Niña years have
considerably increased
in
the recent years.
Scientists argue that
this is the result of
climate variability and
change (instability)
and
This trend is likely to
continue in future as we
are in a stage of
changing climate;
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*2008-09
13
*2009-11
So,
more
frequent
extreme
events
are
likely in the future—
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El Niño/ La Niña, Global Temperatures, and Precipitation

El Niño
Asia
Africa

NA
SA
La Niña
Asia
Africa
SA
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Climate Change: Trend in Sea Level Change (1993-2008), PDO
Global Context
Green,
Yellow, Red:
Rising SL;
Blue, purple:
Falling SL
Other Climate Change (Hurricane Katrina)
Global to Local context
Pacific Storms Storms
Coastal storms, and the strong winds, heavy rains, and high seas that accompany
them, pose a threat to the lives and livelihoods of the peoples of the Pacific.
http://www.pacificstormsclimatology.org/index.php
?page=partners
Pacific Storms (formerly PRICIP) is focused on
improving our understanding of patterns and trends
of storm frequency and intensity - “storminess”- within
the Pacific region.
♦ It is exploring how the climate-related processes that
govern extreme storm events are expressed within
and between three thematic areas: heavy rains, strong
winds, and high seas.
♦ It is developing a suite of extremes climatologyrelated data and information products.
Daily Time Series – Water levels
(all storm..)
(all tide..)
(storm, tide..)
Land Subsidence
Subsidence on the coast of Turkey following
an earthquake in 1999
Non-Climate Drivers
 Port/harbour construction
 Coastal protection works
 Upstream damming for freshwater supply
 Hydroelectric power
 Deforestation
 Coastal subsistence due to ground water abstraction—particularly significant in delta
region
 Socio-economic scenario changes in coastal regions including urbanization
 Geological natural hazards—earthquake.
Uncertainty in Local Predictions
 Relative sea level rise: global and regional components plus land movement
 Land uplift will counter any global sea level rise


Land subsidence will exacerbate any global sea level rise
Other dynamic oceanic and climatic effects cause regional differences (oceanic
circulation, wind and pressure, and ocean-water density differences add additional
component)
Science Summary
 Under a high-emissions scenario, a sea-level rise of up to a meter or more by the
end of the century is plausible.
 Changes in the frequency and magnitude of extreme sea level events, such as
storm surges combined with higher mean sea level, will lead to escalating risks of
coastal inundation. Under the highest sea-level rise scenario by mid-century,
inundations that previously occurred once every hundred years could happen
several times a year
 Sea-level rise will not stabilise by 2100. Regardless of reductions in greenhouse
gas emissions, sea level will continue to rise for centuries; an eventual rise of
several meters is possible.
1.3 (II) Potential Impacts
Effect category
Example effects on the coastal Environment
Bio-geophysical




Displacement of coastal lowlands and wetlands
Increased coastal erosion
Increased flooding
Salinization of surface groundwater
Socio-economic






Loss of property and lands
Increased flood risk/loss of life
Damage to coastal infrastructures
Loss of renewable and subsistence resources
Loss of tourism and coastal habitants
Impacts of agriculture/aquiculture and decline soil and
water quality
Example Effects of Climate Change on the Coastal Zone (2)
Effect category
Example effects on the coastal Environment
Secondary impacts
of accelerated sea
level rise
 Impact on livelihoods and human health
 Decline in healthy/living standards as a result of decline
in drinking water quality
 Threat to housing quality
Infrastructure and
economic activity
 Diversion of resources to adaptation responses to sea
level rise impacts
 Increasing protection costs
 Increasing insurance premiums
 Political and institutional instability, and social unrest
 Threats to particular cultures and ways of life
Biophysical Impacts
Climate driver
(trend)
Main physical/ecosystem effects on coastal
ecosystems
CO2 concentration
 Increased CO2 fertilization, decreases ocean acidification
negatively impacting coral reefs and other pH
SST (I, R)
 Increased stratification/changes circulation; reduced incidence
of sea ice at higher latitudes; increased coral bleaching and
mortality; poleward species migration; increased algal blooms.
(I: increasing, R:Regional
variability)
Sea level (I, R)
 Inundation, flood and storm damage; erosion; saltwater
intrusion; rising water tables/impeded drainage; wetland loss
(and change)
Storm Intensity (I, R)
 Increased extreme water levels and wave heights; increased
episodic erosion, storm damage, risk of flooding and defence
failure
 Altered surges and storm waves and hence risk of storm
damage and flooding
Storm frequency (?,
R); Storm Track (?, R)
Wave Climate
Run-off (R)
 Altered wave conditions, including swell; altered patterns of
erosion and accretion; re-orientation of beach plan form
 Altered flood risk in coastal lowlands; altered water
quality/salinity; altered fluvial sediment supply; altered
circulation and nutrient supply.
Vulnerable Regions Mid-estimate (45 cm) by the 2080s
Caribbean
Pacific
Oc ean
SMALL
ISLANDS
A
C
PEOPLE ATRISK
(millions per region)
A
> 50 million
B
10 - 50 million
C
< 10 million
region boundary
vulnerable island region
C
Indian
Oc ean
SMALL
ISLANDS
B
Coastal Hotspots
 Low-lying coastal areas, deltas and countries—many of which are small island developing
states—and less developed countries are especially vulnerable to climate change
impacts.
 Other vulnerability hot spots include areas with poor and insecure land tenure, and dense
or urbanized populations that will have to migrate with sea level rise.
Atolls
Impacts of Climate Change: Antigua and Barbuda
•
Damage to critical habitats (beaches, mangroves, sea grass beds, coral reefs)
•
Loss of wetlands, Lands due to Sea level change
•
Increased coral bleaching as a result of a 2°C increase SST by 2099
•
Destruction to coastal infrastructure, loss of lives and property
•
Changes in coastal pollutants will occur with changes in precipitation and runoff
•
General economic losses to the country
Source: http://unfccc.int/resource/docs/natc/antnc2.pdf
Also see: http://unfccc.int/national_reports/non-annex_i_natcom/items/2979.php
Impacts of Climate Change: Venezuela
•
Venezuela is in the midst of a genuine power and water crisis. There may not be a clear
cut answer to this question “What is causing Venezuela's energy crisis”, and different
people provide differing interpretations.
Among others, pointing the finger at weather changes, President Chávez said “It's El Niño,” partly to
be blamed for this recent crunch;
The El Niño is blamed to have resulted in a lack of rainfall and the cause of water shortages, which in
turn have starved Venezuela's hydroelectric dams which provide approximately three quarters of the
nation's electricity.
Coastal Megacities (>8 million people)
Tianjin
Dhaka
Seoul
Osaka
Istanbul
Tokyo
New York
Shanghai
Manila
Los Angeles
Bangkok
Lagos
Mumbai
Lima
Karachi
Buenos Aires
Rio de Janeiro
Madras
Jakarta
Calcutta
Sea-Level Rise: Summary
New research indicates:
1.
2.
3.
4.
5.
6.
Doubled melting rate of Greenland ice sheet,
Net melting of the Antarctic ice sheet,
Global rise approaching 3.0 mm/yr, twice the rate last century,
Continued heating of atmosphere – heating of water column,
More than 1 m rise is now expected during this century.
30C temperature rise suggests 3-6 m sea-level rise in a century.
There are still major uncertainties in sea-level science, but these latest
results are significant in that:
1.
2.
3.
They do not point in the direction of smaller rates of rise,
They are consistent with the worse case of longstanding predictions,
Counter arguments grow fewer and fewer……