Special Report on the Ocean and Cryosphere in a Changing Climate

Click here to discuss this policy with our chatbot

Category: UNFCCC

Document Type: Ipcc Report

Role: Main

IPCC 2019 Report Summary: Impacts and Adaptation for Low-Lying Islands and Coasts

This document is the Executive Summary of Cross-Chapter Box 9 from the IPCC Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC), published in 2019. Its purpose is to assess the current and projected impacts of ocean and cryosphere changes on Low-Lying Islands and Coasts (LLIC), including Small Island Developing States (SIDS), and to evaluate adaptation options and limits. The scope covers LLIC globally, examining their shared vulnerabilities (e.g., low elevation, human disturbances) and context-specificities across different geographies like cities, megacities, small islands, deltas, and Arctic coasts. The report highlights that LLIC, which host around 11% of the global population, generate about 14% of global GDP, and contain many cultural heritage sites, are already experiencing cascading and compounding climate-related risks. Disproportionately higher risks are projected throughout the 21st century. Vulnerable human communities, particularly in coral reef environments and polar regions, may exceed adaptation limits well before the end of this century, even under low greenhouse gas emission pathways (high confidence). Depending on 21st-century mitigation and adaptation effectiveness, most low-lying regions may face adaptation limits beyond 2100 due to the long-term commitment of sea level rise (medium confidence). The report does not impose specific obligations, deadlines, or compliance dates, nor does it name regulations or statutes. It identifies affected sectors including human communities, populations, economies, cultural heritage, terrestrial and marine ecosystems, built assets, and activities. Adaptation options discussed range from hard engineering and ecosystem-based measures to securing current settings and relocating people, built assets, and activities. The effectiveness of these options depends on the scale of impacts, ecosystems' and societies' adaptive capacity, and the presence of transformational governance (high confidence).

How Climate Copilot helps

  • Get alerts when policies like this change or new ones appear in your sector.
  • Ask AI to summarise, extract obligations, and answer questions — with citations.
  • Organise notes and your own documents alongside the source material.

No signup needed.

Full text:

Cross-Chapter Box 9:
Integrative Cross-Chapter
Box on Low-lying
CCB9
Islands and Coasts
Authors:
Alexandre K. Magnan (France), Matthias Garschagen (Germany), Jean-Pierre Gattuso (France),
John E. Hay (Cook Islands/New Zealand), Nathalie Hilmi (Monaco/France), Elisabeth Holland (Fiji),
Federico Isla (Argentina), Gary Kofinas (USA), Iñigo J. Losada (Spain), Jan Petzold (Germany),
Beate Ratter (Germany), Ted Schuur (USA), Tammy Tabe (Fiji), Roderik van de Wal (Netherlands)
Review Editor:
Joy Pereira (Malaysia)
Chapter Scientist:
Jan Petzold (Germany)
This cross-chapter box should be cited as:
Magnan, A.K., M. Garschagen, J.-P. Gattuso, J.E. Hay, N. Hilmi, E. Holland, F. Isla, G. Kofinas, I.J. Losada, J. Petzold, B.
Ratter, T.Schuur, T. Tabe, and R. van de Wal, 2019: Cross-Chapter Box 9: Integrative Cross-Chapter Box on Low-Lying
Islands and Coasts. In: IPCC Special Report on the Ocean and Cryosphere in a Changing Climate [H.-O. Pörtner, D.C.
Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A. Alegría, M. Nicolai, A. Okem, J.
Petzold, B. Rama, N.M. Weyer (eds.)]. In press.
657

Cross-Chapter Box 9
Executive Summary
Ocean and cryosphere changes already impact Low-Lying Islands and Coasts (LLIC), including Small
Island Developing States (SIDS), with cascading and compounding risks. Disproportionately higher risks
are expected in the course of the 21st century. Reinforcing the findings of the IPCC Special Report on
Global Warming of 1.5ºC, vulnerable human communities, especially those in coral reef environments and polar
regions, may exceed adaptation limits well before the end of this century and even in a low greenhouse gas
emission pathway (high confidence1). Depending on the effectiveness of 21st century mitigation and adaptation
pathways under all emission scenarios, most of the low-lying regions around the world may face adaptation
limits beyond 2100, due to the long-term commitment of sea level rise (medium confidence). LLIC host around
11% of the global population, generate about 14% of the global Gross Domestic Product and comprise many world cultural
heritage sites. LLIC already experience climate-related ocean and cryosphere changes (high confidence), and they share both
commonalities in their exposure and vulnerability to climate change (e.g., low elevation, human disturbances to terrestrial
and marine ecosystems), and context-specificities (e.g., variable ecosystem climate sensitivities and risk perceptions by
populations). Options to adapt to rising seas, e.g., range from hard engineering to ecosystem-based measures, and from
securing current settings to relocating people, built assets and activities. Effective combinations of measures vary across
geographies (cities and megacities, small islands, deltas and Arctic coasts), and reflect the scale of observed and projected
impacts, ecosystems’ and societies’ adaptive capacity, and the existence of transformational governance (high confidence)
{Sections 3.5.3, 4.4.2 to 4.4.5, 5.5.2, 6.8, 6.9, Cross-Chapter Box 2 in Chapter 1}.
Introduction
LLIC are already experiencing the impacts of climate-related changes to the ocean and cryosphere, for both extreme events
and slow onset changes (Sections 4.3.3, 5.3.1 to 5.3.6, 6.2, 6.8, 6.9), due to their low elevation, narrow ecological zonation,
climate sensitive ecosystems and natural resources, as well as increasing anthropogenic pressures (Sections 1.5, 4.3.2).
High levels of impacts to coastal morphology, ecosystems and dependent human communities are detectable today and
disproportionately higher risks are expected in the course of the 21st century (medium evidence, high agreement) (Sections
4.3.4, 5.3.7), even under a low emission pathway compatible with a 1.5ºC global warming (Hoegh-Guldberg et al., 2018; IPCC,
2018). The magnitude of projected impacts (i.e., risks; Cross-Chapter Box 2 in Chapter 1) will depend on future greenhouse
gas emissions and the associated climate changes, as well as on other drivers such as population movement into risk-prone

Tags: Adaptation, Adaptation Planning, Climate Change, Climate Change Risks, Coastal Erosion, Disaster Risk Management, Governance, Housing, Infrastructure, Land Use, Migration, Mitigation, Oceans, Planning, Policy, Report, Research, Spatial Planning

Original Source