RISES –AM –

RESPONSES TO COASTAL CLIMATE CHANGE: INNOVATIVE STRATEGIES FOR HIGH END

SCENARIOS –ADAPTATION AND MITIGATION

Tom Bucx (Deltares)

RISC-KIT final conference, Delft, 7 April 2017

Analyse the implications of high-end scenarios (global warming >2º with respect to pre-industrial level) for vulnerable coastal areas

Better quantification of impacts and vulnerabilities and feasible adaptation

pathways, through 13 case studies - combining local, regional and global approaches - synergies and trade-offs between mitigation and adaptation across scales

Inform policy and decision makers, contributing to EU policies

Start/end: Nov 2013 - Nov 2016 Total budget: 5,6 MEuro 12 partners, Lead by Agustin Sanchez-Arcilla, UPC, Spain http://www.risesam.eu

1. UPC Catalonia Univ Technology

2. GeoEcoMar

National Inst Marine Geology & Geoecology

3. IRTA Inst. Recerca i Tecnologia Agroalimentàries

4. SOTON University of Southampton 5. Deltares Deltares

6. CAU Christian-Albrechts-Universitaet zu Kiel

7. NOC – NERC

National Ocean. Centre - Natural Env Res Council

8. HZG Helmholtz-Zentrum Geesthacht

9. VU-IVM Stichting VU-VUniv

10. GCF Global Climate Forum

11. CMCC Centro Euro-Mediterranea Cambiamenti Climatici

12. UOS University of Sussex

Scal

es

Regional Scale

Catalan Coast Harbours - Beaches Croatian Coast

Local Scale

Elbe - Hamburg Liverpool - Mersey

Low-lying coasts (Holland, Aveiro)

Ebro delta

Danube delta Ho Chi Minh City

Maldives

Global Scale

Global Impacts (DIVA) Global Deltas

Arc

hety

pes

Main Case Studies

Estuaries

Mersey Liverpool

Elbe

Hamburg

Low-lying Coasts

Holland Aveiro

Deltas

Danube Black Sea

Ebro Med. Sea

Cross – Scale Assessment Framework

Drivers

- Climate change - SLR scen. - Socio-Economic scen.

Pressures

- Sea level, waves … - population, land use, …

Impacts

- Flooding - Erosion

Coastal system State / Response

Spatial layers Occupation Base Network

Grey – Soft – Green measures (Convent. – BwN)

D P S I R

Cross – Scale Assessment Framework

Guidelines for the assessment in the case studies 8 step approach Step 1 Case study description using CAS Step 2 Model development and validation Step 3 Impact assessment of reference cases (BaU) Step 4 Impact assessment with additional adaptation options Step 5 Developing and evaluation adaptation pathways Step 6 Stakeholder workshop Step 7 Selection of preferred adaptation pathways Step 8 Implications for global-regional-local levels

Policy briefs

Sea level rise Anticipated future maximum water levels and respective hazard level (AR5) along the Mediterranean coast will already reached by the mid 21st century. Storminess No major changes in frequency are anticipated for whole Europe The Mediterranean and Black Sea will experience a widespread decrease of future storm intensity. NW Europe The changes in sea level extremes under the RCP8.5 scenario show heterogeneous spatial patterns but in general are moderate.

EXTREME SEA LEVELS The societal impacts of sea level change will primarily occur via the extreme levels rather than as a direct consequences of mean sea level changes.

The RCPs are a set of four pathways that lead to radiative forcing levels of 2.6, 4.5, 6 and 8.5 W/m2, by the end of the century. Representative Concentration Pathways (RCP)

EU28 population (in LECZ) – SSP3 • Slightly increase to 48 million in 2025 and consequently

decreases to 32 million in 2100 • Population of the Mediterranean countries declines stronger

(from 12.2 million to 8.6 million) than in northern European countries (from 30.1 million to 21.9 million)

SSP1 describes a sustainable world with low challenges; SSP2 is a ‘Middle of the Road’ pathway; SSP3 assumes regional rivalry with high challenges for both, mitigation and adaptation. SSP4, is characterised by inequality and high challenges for adaptation; SSP5 is the pathway of fossil-fuelled development and has high challenges for mitigation

Shared Socio-Economic Pathways (SSP)

EU28 population (in LECZ) – SSP5 • Increase from 67 million in 2050 to 93 million in 2100 • In the Mediterranean the population grows to 25.6 million

and in the northern European countries to 65.5 million

SSP3

Global population • The Low Elevation Coastal Zone (LECZ), area below 10m

above mean sea-level, constitutes 2% of world’s land area but around 10% of world’s population (600 million people)

• Under every socio-economic scenario population is expected to exceed 1 billion in 2050

SOCIO-ECONOMIC DEVELOPMENT will be a major driver of impacts besides SLR

SSP5

Global

EU28

EU28 Adaptation • Adaptation is affordable for all European nations under most

scenarios • In many cases, hard protection may not be practical or

desirable (e.g. disruption of sediment supply, viability, access) and innovative adaptation options need to be implemented

Total annual costs (dike building, maintenance, flood damages) • For RCP8.5 for the EU28 in 2100 reach 32.9 million under

SSP3 and 91.3 million under SSP5 • These costs can reach up to or even exceed 1.5% of the

annual GDP for some nations but are considerably more affordable for others

Avoided damage • By 2050, for RCP4.5 and RCP8.5 less than 0.1% of GDP • For the high-end 0.5% of GDP by 2050 and up to 14% by

2100

12% of coastline account for 89% of coastal population and 94% of coastal floodplain assets

Global impact Ignoring SLR could result in up to US$ 50 trillion in annual flood damage under the high-end scen. Adaptation is possible, effective and economically robust

• No severe financial or technological limits to reduce flood risk in the 21st century • Coastal flood risk can be maintained at or below today's levels, provided that large

upfront investments can be mobilised where needed

EU28 BARRIERS TO ADAPTATION

• Financial, institutional and social barriers constitute the greatest challenge • On the financial side, adaptation often requires large upfront investments which

are difficult to mobilize, even if the investment is cost efficient on the long run • From an institutional point of view, there is lack of appropriate mechanisms to

deal with different stakes at hand

6 Coastal Archetypes with high-risk for sea level rise

The main impacts of rising sea levels are erosion, inundation (flooding), rising groundwater levels and saltwater intrusion

Adaptation strategies and options for the high risk coastal archetypes

• Traditional interventions are expected to become difficult to sustain under high-end climate scenarios • Natural (BwN) solutions are better to cope with varying wave conditions and rising sea-levels due to

less energy needs and costs associated to their implementation

Speed and magnitude of sea level rise, and socio-economic developments are uncertain Some adaptation measures requiring large investments Need for an approach to support decision making under uncertainty that produces a dynamic, flexible plan that can be adapted as conditions change

Dynamic Adaptive Policy Pathways

Haasnoot et al. (2013) Glob. Env. Change. 10.1016/j.gloenvcha.2012.12.006

Adaptation tipping points and pathways

• These generic maps will serve as inspiration to develop tailor-made adaptation pathways for any specific coastal area pertaining to the archetype(s)

• Linked to local policy objectives, adaptation measures and their tipping points

Generic adaptation pathways for the 6 coastal archetypes

Pathway Generator: to explore policy pathways in an interactive way https://publicwiki.deltares.nl/display/AP/Pathways+Generator

EXPLORING ADAPTATION PATHWAYS HAS MULTIPLE BENEFITS • Assessment of coastal management, to know to what extent they can meet their own policy objectives

while maintaining the same protection strategy • Generates insight in the possible adaptation measures, their life time, and follow up measures • Creates insight in decisions for the short term and decision options for the long term • Opens up the minds for explicitly considering a diversity of adaptation measures • Involves stakeholders to co-produce long term coastal zone adaptation strategy by discussing and

explicating their preferences and responsibilities.

WHAT CAN EU-POLICYMAKERS DO? • Stimulate local, regional and national governments to apply adaptive planning regarding the impacts

of sea level rise, through the application of adaptation pathways as a way to deal with the uncertainties and long-term implications of short-term action

• Focus EU-policy by organize research- and adaption programs around these high risk coastal archetypes and stimulate the development and implementation of locally or regionally tailored coastal adaptation pathways

• Remove institutional barriers and increase research budgets and programs with regard to the governance of climate adaptation

THANK YOU

Upper limit (95%, RCP8.5), 1.8m

High-end climate change Global sea level projections

Drivers Climate change Economic change Population growth

Coastal system (state) Impacts (Coastal System Indicators)

Bas

e la

yer

Morphology - Coast length / type (Open, Estuary, Delta) - Coast line position - Beach width - Height / Slope gradient Natural resources - Available sediment / sediment load - Availabel fresh water / river discharge - Available oil, gas, coal, peat, salt Biotopes/ Habitats - Dunes, salt marshes, mangroves, beach - Habitat productivity

Morphology - Affected length (per coastal type) - Coastline retreat - Beach erosion rate - Land subsidence rate Natural resources - Loss of available natural resources (sediment, fresh water, oil, gas, coal, salt) - Change in river sediment load - Change in (seasonal ) river discharge - Change in salt concentration in water and soil - Quality degradation of water and soil - Green house gases non-emitted or sequestered Biotopes/ Habitats - Loss or change of biodiversity / habitats - Loss of habitat area or habitat productivity

Evaluation criteria of adaptation measures • Effectiveness Policy criteria: • Robustness • Flexibility and adaptability • Costs • Implementation feasibility

Stakeholders and decision-

makers

Policy objectives

Targets Priorities

Dec

isio

n pr

oces

s

Pressures Climate change pressures - Sea-level rise - Temperature change - Precipitation change Extreme events - Extreme water levels (by storm surge or tide) - Extreme waves (runup/ overtopping) - Extreme river discharges - Extreme precipitation Socio-economic pressures - Use of natural resources - Urbanisation - Increased tourism - Land use change - Pollution - Sediment retention - Subsidence

Responses (adaptation) Grey measures -Sand nourishments - marshland stabilization Green measures - Natural foreshore sedimentation - Beach and habitat restoration - Afforestation - Mangroves - Ecosyst preservation/restoration

Net

wor

k la

yer

Coastal protection structures - Dikes, breakwaters, groynes, facilities Transport infrastructure - Roads , railways - Waterways, harbours - Cabless, pipes (electricity, gas, water) - Power stations - Oil refineries

Coastal protection structures - Affected infrastructure and related facilities - Barrier breaching - Overtopping Transport infrastructure -Affected infrastructure (roads, rail - & waterways, cables, pipes) - Affected harbours (a.o. agitation) - Reduction of transport and port operations

Grey measures - Dikes/sea walls; tidal barrages - Elevating infrastructure Green measures - Eco-dike - Dune development Soft measures -Relocation -Diversion of maritime traffic

Occ

upat

iona

l lay

er Population - Population density in flood-prone areas - Number of tourists Land use functions - Surface areas (urban, industrial, rural/agricultural, natural, archaeological/ heritage , recreational) Economy - Economic performance of area / GDP - Exports from the area - Agricultural productivity

Population - Population affected by floods or droughts Land use functions - Affected areas (urban, industrial, agricultural, natural, recreational - including beach) - Flood depth, area and duration Economy - Loss of tourism / number of tourists - Damage to assets, productivity, GDP - Decrease in exports

Grey measures - Land reclamation - Water pumping Green measures -Conversion of land use -Conversion of agriculture Soft measures - Creation of inundation areas - Set-back zones - Spatial planning - Flood-proof or floating buildings

Adaptation

Policy indicator

s

Adaptation Coastal system

indicators Mitigation

Combined Spatial Layer and DPSIR framework for RISES-AM- (detailed version)