sea level changes: implications for the coast richard warrick international global change institute...
DESCRIPTION
Average of models, All emission scenarios Temperature Change (deg.C) Global Temperature Change (IPCC, 2001) Future ProjectionsTRANSCRIPT
Sea Level Changes: Implications for the Coast
·I·G·C·I·
RICHARD WARRICKInternational Global Change Institute (IGCI)
University of Waikato
Major sources of uncertainty:• GHG emission rates GHG emission rates
(socio-economic and technological uncertainty)(socio-economic and technological uncertainty) • Climate sensitivity Climate sensitivity
(scientific modelling uncertainties)(scientific modelling uncertainties)
• Land ice response (additional uncertainty for sea level change)
FUTURE WARMING and SEA LEVEL RISE – how much ?
Average of models, All emission scenarios
Tem
pera
ture
Cha
nge
(deg
.C)
Global Temperature Change
(IPCC, 2001)
Future Projections
Average of models, All emission scenarios
All models, All emission scenarios
Tem
pera
ture
Cha
nge
(deg
.C)
Global Temperature Change
1.4 oC lowest scenario, low sensitivity
5.8 oC highest scenario, high sensitivity
(IPCC, 2001)
Future Projections
Global Sea-level Rise
(IPCC, 2001)
Average of models, All emission scenarios
All models, All emission scenarios
Sea-
leve
l Ris
e (m
etre
s)
All models, All emission scenarios, Land-ice uncertainty
Future Projections
8 cm lowest scenario, low sensitivity, low land-ice
88 cm highest scenario, high sensitivity, high land-ice
Global Sea-level Rise
(IPCC, 2001)
Average of models, All emission scenarios
All models, All emission scenarios
Sea-
leve
l Ris
e (m
etre
s)
All models, All emission scenarios, Land-ice uncertainty
Future Projections
Aspects of future change that are important for the coast• Sea level • Sea-surface temperature• Rainfall amounts, intensity• Changes in ENSO• Storm frequency and intensity• Storm surge risks• Wind and wave regimes
WARNING!!: PREDICTIONS OF REGIONAL-SCALE CHANGES ARE STILL VERY
UNCERTAIN
CoastCLIM: Modelling Shoreline Change
CoastCLIMModelling Change in Shoreline Position
dC/dt = (Ceq - C)/τ + Εs Shoreline Change
τ is τime (yrs)C is τhe shoreline posiτion (m) relaτive τo τhaτ of τ=0,Ceq is τhe equilibrium value of Cτ is τhe shoreline response τime (yrs)Εs is a sτochasτically-generaτed sτorm erosion facτor
Ceq = z l/(h+d) + S Bruun Rule
z is sea level change (m)l is τhe closure disτance (m)h is τhe depτh of maτerial exchange (m)d is τhe dune heighτ (m)S is long τerm accreτion (m)
dC/dt = (Ceq - C)/τ + Εs Shoreline Change
τ is τime (yrs)C is τhe shoreline posiτion (m) relaτive τo τhaτ of τ=0,Ceq is τhe equilibrium value of Cτ is τhe shoreline response τime (yrs)Εs is a sτochasτically-generaτed sτorm erosion facτor
Ceq = z l/(h+d) + S Bruun Rule
z is sea level change (m)l is τhe closure disτance (m)h is τhe depτh of maτerial exchange (m)d is τhe dune heighτ (m)S is long τerm accreτion (m)
CoastCLIMModelling Change in Shoreline Position
dC/dt = (Ceq - C)/τ + Εs Shoreline Change
τ is τime (yrs)C is τhe shoreline posiτion (m) relaτive τo τhaτ of τ=0,Ceq is τhe equilibrium value of Cτ is τhe shoreline response τime (yrs)Εs is a sτochasτically-generaτed sτorm erosion facτor
Ceq = z l/(h+d) + S Bruun Rule
z is sea level change (m)l is τhe closure disτance (m)h is τhe depτh of maτerial exchange (m)d is τhe dune heighτ (m)S is long τerm accreτion (m)
CoastCLIMModelling Change in Shoreline Position
dC/dt = (Ceq - C)/τ + Εs Shoreline Change
τ is τime (yrs)C is τhe shoreline posiτion (m) relaτive τo τhaτ of τ=0,Ceq is τhe equilibrium value of Cτ is τhe shoreline response τime (yrs)Εs is a sτochasτically-generaτed sτorm erosion facτor
Ceq = z l/(h+d) + S Bruun Rule
z is sea level change (m)l is τhe closure disτance (m)h is τhe depτh of maτerial exchange (m)d is τhe dune heighτ (m)S is long τerm accreτion (m)
·I·G·C·I·CoastCLIM Outputs
Shoreline Change1940-2100
Shoreline Change1940-2100
Shoreline Change1940-2100
Bay of Plenty Application
Shoreline in 2100
Present shoreline
Bay of Plenty Application
Shoreline in 2100
Present shoreline
DEMONSTRATION