sea level change around the philippines - amazon s3 · 2015-12-03 · sea level change wendy...

Sea level change

Wendy Clavano

Overview

Global sea levelchange

Regional variability

Local factors andlocal risk

Temporalvariability

Water level effects:Davao example

Risks from sealevel rise

Summary

Resources andreferences

Thanks

Extras

Sea level change around the Philippines

Wendy Clavano

Institute of Environmental Science for Social Change (ESSC)

Conference on Internal Migration and DisplacementDavao City, Philippines

20 May 2012

Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

OverviewI How are sea levels changing around the Philippines?I Global change, regional variability, local factorsI Spatial variability, but also temporal variabilityI Effect of rising sea level on extreme eventsI Risks to ecological services and the human

ecosystem

Sea level change

Wendy Clavano

Overview




Temporalvariability



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Extras

Global sea level changeMain factors causing global increase

I thermal expansionI melting of small glaciersI ice loss from the Greenland and West Antarctic Ice

Sheets

Sea level change

Wendy Clavano

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Projected range of mean sea level rise1

I Eustatic rate: 3.1(±0.4)mm/yr (1992-2011)

Synthesis and Outlook for the Future 409

Figure 13.5 Projected sea - level rise for the 21st century. The projected range of global averaged sea - level rise from the IPCC (2001) assessment report for the period 1990 – 2100 is shown by the lines and shading (the dark shading is the model average envelope for the range of greenhouse gas scenarios considered, the light shading is the envelope for all models and for the range of scenarios, and the outer lines include an allowance for an additional land - ice uncertainty). The AR4 IPCC projections (90% confi dence limits) made in 2007 are shown by the bars plotted at 2095, the magenta bar is the range of model projections, and the red bar is the extended range to allow for the potential but poorly quantifi ed additional contribution from a dynamic response of the Greenland and Antarctic Ice Sheets to global warming. The red arrow indicates that “ larger values cannot be excluded, but understanding of these effects is too limited to assess their likelihood or provide a best estimate or an upper bound for sea - level rise ” ; updated from Church et al. (2008) .

1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 21000.0

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Additional contributionsfrom potential ice−sheetdynamic processes

Larger valuescannot be excluded

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about 20%) far from the decaying ice sheets. As a result, ice - sheet contributions to future sea - level rise are likely to have a disproportionate impact in some far - fi eld and potentially vulnerable regions.

13.4 Projections of Sea - Level Rise for the 21st Century and Beyond

The IPCC Third Assessment Report (TAR; IPCC 2001 ) projections of sea - level rise were expressed in the form of globally averaged levels for 2100 compared with 1990 levels (the lines and shaded regions in Figure 13.5 ), while the AR4 (IPCC 2007 ) were expressed for the 2090 – 2100 decade (shown as the bars plotted at 2095 in Figure 13.5 ) compared with 1980 – 2000 averages (approximately equal to the 1990 values).

The average of the TAR model projections for the full range of greenhouse gas scenarios is about 30 – 50 cm (dark shading in Figure 13.5 ). The range of all model projections over all scenarios is about 20 – 70 cm (light shading). The full range of projections, including an allowance for uncertainty in estimates of contributions from land - based ice, were for a sea - level rise of 9 – 88 cm (outer black lines).

The AR4 model projections are composed of two parts. The fi rst part consists of the estimated sea - level rise (with a 90% confi dence range) from ocean thermal expansion, glaciers and ice caps, and modeled ice - sheet contributions and is for a sea - level rise of 18 – 59 cm in 2095 (the magenta bar). This contribution is similar to, but slightly smaller than, the equivalent range from the TAR (the light shaded

Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

Regional variability2

I Rate around the Philippines: 5.8 (±0.6)mm/yr

ANRV399-MA02-06 ARI 13 November 2009 17:23

Sea level change (mm year–1)

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Figure 3(a) Map of spatial trend patterns of observed sea level between January 1993 and December 2008. (b) Same as (a) but a uniform globalmean trend of 3.4 mm year−1 has been removed.

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Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

Regional variabilitySome factors affecting regional changes

I land water storageI gravitational attraction of water to land or ice massI vertical land movement (subsidence or uplift)

Sea level change

Wendy Clavano

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Temporalvariability



Summary


Thanks

Extras

Increase in sea levels by 20503

I Not relative sea level

Sea level change

Wendy Clavano

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Summary


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Coastal vulnerability index4

I mean sea level trendI mean significant wave heightI mean tidal rangeI coastal slopeI (coastal erodibility)I (rate of erosion)

Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

Coastal vulnerability indexI Physical factors, not including human vulnerability

Sea level change

Wendy Clavano

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Temporalvariability



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Extras

ENSO and the summer monsoon (JAS)I high sea levels match high MEI values

1993 1994 1995 1996 1997 1998

1999 2000 2001 2002 2003 2004

2005 2006 2007 2008 2009 min = −27.1; max = 36.2

JAS mean SSHA [mm]

log

scal

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−30−15−7−4−202471530

Sea level change

Wendy Clavano

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ENSO and the winter monsoon (DJF)I high anomalies when MEI values switch extremes

1993 1994 1995 1996 1997 1998

1999 2000 2001 2002 2003 2004

2005 2006 2007 2008 2009 min = −27.7; max = 22.3

DJF mean SSHA [mm]

log

scal

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−30−15−7−4−202471530

Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

Water level effects: Davao exampleI Frequency distribution of water levels, median ∼2m

0 1 2 3 4 50.5

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3.5Tidal levels at Davao (1984−1997)

Frequency of hourly events (x1000)

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Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

Effect of a 20-cm increase in mean sea levelI Increase in frequency of high water levels

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Frequency analysis of annual maximum series for Davao tide gauge, 1984−1997

ObservationsFitted distribution95% confidence interval20cm increase in sea level1996 maximum water level

Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

Risks from sea level rise5

I Coastal flooding (surge and backwater effect)I Land loss (wetlands, erosion)I Freshwater aquifer contaminationI Soil degradation from salinization

Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

Risk to human ecosystemsI Disruption of lives and livelihoodI Displacement of property and industriesI Destruction of resources that provide ecological

servicesI Destabilization of resource tenure

Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

SummaryI Global change requiring local actionI Spatial and temporal variabilityI Issues other than simply water levelsI Risks to both natural and human ecosystems

Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

ReferencesI 1Church, J.A. et al. (2010) in Understanding

Sea-Level Rise and Variability edited by J. A. Churchet al., pp. 402–419.

I 2Cazenave, A. and W. Llovel (2010) Annu. Rev. Mar.Sci. 2, 145-73.

I 3Clavano, W. R., Ecojesuit (Programs and Projects),http://ecojesuit.com/, 30 April 2012.

I 4Thieler, E. R. and E. S. Klose (1999-2000) USGSOpen File Reports, http://woodshole.er.usgs.gov/project-pages/cvi/.

I 5Nicholls, R. J. et al. (2007) in IPCC WGII AR4,edited by M. L. Parry et al., pp. 315–356.

http://ecojesuit.com/

http://woodshole.er.usgs.gov/project-pages/cvi/

http://woodshole.er.usgs.gov/project-pages/cvi/

Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

ResourcesI Mean significant wave height: Young, I. R. et al.

(2011) Science 332, 451–455.I Topography & bathymetry: S2004 v14.1, 22 Jun

2011.I Vector shoreline: GSHHS v1.5, 14 Sep 2004

(updated v2.2.0, Jul 2011).I Tidal range: FES2004, 22 Mar 2007.I Mean sea level trends (Oct 1992–Dec 2011): AVISO,http://www.aviso.oceanobs.com/.

I GIA model: Peltier, W. R. (2004) Ann. Rev. EarthPlanet. Sci. 32, 111–149.

I Philippine human exposure and vulnerability indices:Manila Observatory (2005),http://vm.observatory.ph/.

I Geohazard maps: DENR MGB (2011),http://geohazard.essc.org.ph/.

http://www.aviso.oceanobs.com/

http://vm.observatory.ph/

http://geohazard.essc.org.ph/

Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

ThanksI University of ArizonaI Brigham Young UniversityI EPaM, Commission universitaire pour le

Développement (Belgium)I M. Mulligan, King’s College LondonI F. P. Siringan, Marine Science Institute, U.P. DilimanI I. Young, Australian National UniversityI S. Zieger, Swinburne University of TechnologyI P. Woodworth, U.K. National Oceanography CentreI Natural Resources Canada Library

Sea level change

Wendy Clavano

Overview




Temporalvariability



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Extras

Number of people at risk from sea level rise6

30 Robert J. Nicholls

Figure 2.9 The regions most vulnerable to coastal fl ooding, based on an illustrative scenario for the 2080s, assuming a middle estimate of global sea - level rise by that

time of 45 cm (note: the African coastline comprises three “ regions ” ). (Adapted from Nicholls et al. 1999 .)

2.6 Future Impacts of Sea - Level Rise

The future impacts of sea - level rise will depend on a range of factors, including the degree to which sea - level rise accelerates, the level and manner of coastal development, and the success (or failure) of adaptation. Assessments of the future impacts of sea - level rise have taken place on a range of scales from local to global. They all confi rm potentially large impacts following Table 2.1 , especially increases in inundation fl ooding and storm damage. Taking account of population expo-sure, sensitivity, and adaptive capacity, South and Southeast Asia and Africa appear to be most vulnerable in absolute terms due to storm - induced fl ooding combined with sea - level rise (Figure 2.9 ). Nicholls et al. (1999) estimated that for a roughly 40 - cm global rise in sea level by the 2080s and the IS92a socioeconomic scenarios (the business - as - usual emissions (and socioeconomic) scenarios used prior to the Special Report on Emission Scenarios (SRES) scenarios), more than 70 million people might be impacted in Asia, and more than 10 million people in Africa. Signifi cant residual risk will remain in other coastal areas of the world such as around the southern North Sea, and major fl ood disasters remain possible in any coastal region. Under the SRES climate and socioeconomic scenarios the

6Nicholls, R. J. (2010) in Understanding Sea-Level Rise and Variability, edited by J. A. Church et al., pp.17–51.

Sea level change

Wendy Clavano

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Predicted tide for Davao, January 1984I No weather effects

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 310.5

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3.5Example of semidiurnal tidal type (Davao tide gauge) with moon phases

Time (days in January 1984)

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First Quarter Full Moon Last Quarter New Moon

Sea level change

Wendy Clavano

Overview




Temporalvariability



Summary


Thanks

Extras

Global MSL and MEI values7

GMSL (60-day smoothed, detrended, seasonal signals removed)

Multivariate ENSO Index

7CU Sea Level Research Group (2011), http://sealevel.colorado.edu/?page=1.

http://sealevel.colorado.edu/?page=1

sea level change around the philippines - amazon s3 · 2015-12-03 · sea level change wendy...

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