Lead Authors: Marco Bindi (Italy), Sally Brown (UK), Ines Camilloni (Argentina), Arona Diedhiou (Ivory Coast/Senegal), Riyanti Djalante (Japan/Indonesia), Kristie L. Ebi (USA), Francois Engelbrecht (South Africa), Joel Guiot (France), Yasuaki Hijioka (Japan), Shagun Mehrotra (USA/India), Antony Payne (UK), Sonia I. Seneviratne (Switzerland), Adelle Thomas (Bahamas), Rachel Warren (UK), Guangsheng Zhou (China)

Impacts of 1.5°C Global Warming on Natural and Human Systems

Coral reefs can provide significant coastal protection benefits to people and property. Here we show that the annual expected damages from flooding would double, and costs from frequent storms would triple without reefs. For 100-year storm events, flood damages would increase by 91% to $US 272 billion without reefs. The countries with the most to gain from reef management are Indonesia, Philippines, Malaysia, Mexico, and Cuba; annual expected flood savings exceed $400 M for each of these nations. Sea-level rise will increase flood risk, but substantial impacts could happen from reef loss alone without better near-term management. We provide a global, process-based valuation of an ecosystem service across an entire marine biome at (sub)national levels. These spatially explicit benefits inform critical risk and environmental management decisions, and the expected benefits can be directly considered by governments (e.g., national accounts, recovery plans) and businesses (e.g., insurance). Coral reefs provide significant coastal protection from storms but they have experienced significant losses. Here the authors show that the annual damages from flooding would double globally without reefs and they quantify where reefs provide the most protection to people and property.

/pdf/the-global-flood-protection-savings-provided-by-coral-reefs-36qjayyla3.pdf

The global flood protection savings provided by coral reefs

There is growing awareness that ‘nature-based solutions' (NbS) can help to protect us from climate change impacts while slowing further warming, supporting biodiversity and securing ecosystem servi...

https://royalsocietypublishing.org/doi/pdf/10.1098/rstb.2019.0120

Understanding the value and limits of nature-based solutions to climate change and other global challenges

Do Not Cite, Quote or Distribute 4-1 Total pages: 139 1 Chapter 4: Sea Level Rise and Implications for Low Lying Islands, Coasts and Communities 2 3 Coordinating Lead Authors: Michael Oppenheimer (USA), Bruce Glavovic (New Zealand), Tuhin Ghosh 4 (India) 5 6 Lead Authors: Amro Abd-Elgawad (Egypt), Rongshuo Cai (China), Miguel Cifuentes-Jara (Costa Rica), 7 Rob Deconto (USA), John Hay (Cook Islands), Jochen Hinkel (Germany), Federico Isla (Argentina), 8 Alexandre K. Magnan (France), Ben Marzeion (Germany), Benoit Meyssignac (France), Zita Sebesvari 9 (Hungary), AJ Smit (South Africa), Roderik van de Wal (Netherlands) 10 11 Contributing Authors: Maya Buchanan (USA), Gonéri Le Cozannet (France), Catia Domingues 12 (Australia), Virginie Duvat (France), Tamsin Edwards (UK), Miguel D. Fortes (Philippines), Thomas 13 Frederikse (Netherlands), Jean-Pierre Gattuso (France), Robert Kopp (USA), Erwin Lambert (Netherlands), 14 Elizabeth McLeod (USA), Mark Merrifield (USA), Siddharth Narayan (US), Robert J. Nicholls (UK), 15 Fabrice Renaud (UK), Jonathan Simm (UK), Jon Woodruff (USA), Poh Poh Wong (Singapore), Siyuan Xian 16 (USA) 17 18 Review Editors: Ayako Abe-Ouchi (Japan), Kapil Gupta (India), Joy Pereira (Malaysia) 19 20 Chapter Scientist Maya Buchanan (USA) 21 22 Date of Draft: 20 April 2018 23 24 Notes: TSU Compiled Version 25 26

/pdf/sea-level-rise-and-implications-for-low-lying-islands-coasts-1ptd3trc7d.pdf

Sea Level Rise and Implications for Low Lying Islands, Coasts and Communities

Urban natural environments as nature-based solutions for improved public health – A systematic review of reviews

An investigation of scale issues in coastal flooding using a conceptual systems model

Introduction Coastal floods account for a large proportion of the damage to life and property due to natural disasters world-wide. Out of the 15 greatest natural disasters in the world in terms of monetary losses between 2004 and 2008, 14 were coastal (Kron 2008). However, despite the enormity of a particular flood event, people often return to a flood-prone area after a disaster (Cigler 2007; Parker 1995). This necessitates a need for pro-active management of coastal flood systems. A coastal flood system may be thought of as a geographic unit comprising all natural and human elements potentially affected by coastal floods.

Investigating the source – pathway – receptor – consequence framework for coastal flood system analyses

Nature Based Solutions: Lessons from Across the World

Bridging the Gap between Engineering and Ecology: Towards a Common Framework for Conventional and Nature-Based Coastal Defenses

With coastlines becoming increasingly urbanised worldwide, the economic risk posed by storm surges to coastal communities has never been greater. Given the financial and ecological costs of manmade coastal defences, the past few years have seen growing interest in the effectiveness of natural coastal &#8220;defences&#8221; in reducing the risk of flooding to coastal properties, but estimating their actual economic value in reducing storm surge risk remains a challenging subject.In this study, we estimate the value of mangroves in reducing annual losses to property from storm surges along a large stretch of coastline in Florida (USA), by employing a catastrophe modelling approach widely used in the insurance industry. We use a hydrodynamic coastal flood model coupled to a property loss model and a large property exposure dataset to estimate annual economic losses from hurricane-driven storm surges in Collier County, a hurricane-prone part of Florida. We then estimate the impact that removing mangroves in the region would have on average annual losses (AAL) caused by coastal flooding. We find that mangroves reduce AAL to properties behind them by over 25%, and that these benefits are distributed very heterogeneously along the coastline. Mangrove presence can also act to enhance the storm surge risk in areas where development has occurred seaward of mangroves.In addition to looking at annual losses, we also focus on the storm surge caused by a specific severe event in Florida, based on Hurricane Irma (2017), and we estimate that existing mangroves reduced economic property damage by hundreds of millions of USD, and reduced coastal flooding for hundreds of thousands of people.Together these studies aim to financially quantify some of the risk reduction services provided by natural defences in terms of reducing the cost of coastal flooding, and show that these services can be included in a catastrophe modelling framework commonly used in the insurance industry.

Siddharth Narayan

Papers

An investigation of scale issues in coastal flooding using a conceptual systems model

Investigating the source – pathway – receptor – consequence framework for coastal flood system analyses

Nature Based Solutions: Lessons from Across the World

Bridging the Gap between Engineering and Ecology: Towards a Common Framework for Conventional and Nature-Based Coastal Defenses

What value do mangroves have in reducing the cost of storm surges