Adaptation pathways to uncertain climate change

Marjolijn Haasnoot and colleagues

Adaptation pathways to uncertain climate change

the case of sea-level rise

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Identify risks, objectives, uncertainties and (long-term) adaptation needs.

Map solution space, including options and their thresholds, limits and opportunities.

Design a dynamic plan and implement intial actions and monitoring system

Explore and evaluate adaptation pathways.

Align with maintenance and social goals.

Monitor for signals about progress, opportunities and thresholds.

adaptation pathways

Systematic approach to adaptation pathways planning

Haasnoot et al. 2013, IPCC SROCC 2019. Several guidances exist: CRIDA, World Bank, national guidances

Long-term sea-level rise necessitates a commitment to adaptation Population at risk to a 100-year event increases

Without adaptation, the population at risk of a 100-year flood increases 21%

at 0.15 m of sea level rise and doubles at 0.75 m SLR. Large increases occur in Asia, but also in Africa and Europe

Uncertainty Antarctica

https://doi.org/10.1016/j.crm.2021.100355 Impacts beyond

2100

Long-term sea-level rise necessitates a commitment to adaptation Population at risk to a 100-year event increases

Without adaptation, the population at risk of a 100-year flood increases 21%

at 0.15 m of sea level rise and doubles at 0.75 m SLR. Large increases occur in Asia, but also in Africa and Europe

Uncertainty Antarctica

https://doi.org/10.1016/j.crm.2021.100355 Impacts beyond

2100

Timing of exceedance of risk thresholds

https://doi.org/10.1016/j.crm.2021.100355

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Adaptation options

Beschermen

Katwijk

Maeslantkering

Duitsland, Noordzee

Zandmoter, Ter Heijde

Mangroves, salt marshes

Protect

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Adaptation options

Beschermen

Floating city Idea New York

Advance

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Adaptation options

Beschermen

Schoonschip Amsterdam, © Isabel Nabuurs)

Floating paviljoen, Rotterdam

Second levee, natural land raising Ho Chi Minh City, © Stijn Koole

Groningen Zeeland © WNF/NIOZ

Accommodate

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Adaptation options

Beschermen

>

Noordwaard, ruimte voor de rivier

Kingston, USA

Avoid

x

Adaptation options have thresholds, limits, opportunities

• Solution space is shaped by biophysical, cultural, socio-economic, political, institutional dimensions.

• ‘Hard’ (unsurpassable) limits and

‘soft’ (surpassable) limits, e.g.:

− Technical

− Physical (space, material)

− Cost-benefit

− Law/regulations

− Financial

− Time

• Innovation needed to address scale and rate

10 https://doi.org/10.1007/s10113-020-01623-8

Wadplaten

Kritische stijgsnelheid

~6 mm/jaar Texel, Vlie

~10 mm/jaar Borndiep

~30 mm/jaar Pinkegat

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Adaptation pathways to (long-term) ongoing sea-level rise

Haasnoot et al. 2021, Science, https://doi.org/10.1126/science.abi6594

Nested pathways

Haasnoot et al. 2021, Science, 10.1126/science.abi6594

Haasnoot et al. 2021, Science, 10.1126/science.abi6594

Questions?

@lijnonline

marjolijn.Haasnoot@deltares.nl

Exploring pathways inc. thresholds, limits and opportunities can:

- support staging adaptation and help to

- break this into manageable steps over time,

- align it with maintenance or other social goals and - implement depending on how the future unfolds.

Long term sea-level rise necessitates a commitment to adaptation now.

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Beschermen

>

BeschermenAdvance

BeschermenAccommodate

Avoid

x