Resilient coasts: optimising co-benefit solutions (Co-Opt)

海洋和社会在沿海相互作用最强烈，那里的社区既受益于海洋环境，又受到海洋环境的威胁。2017年，在英国政府的风险登记册上，沿海洪水是仅次于大流行流感的第二高风险。仅在英格兰，就有超过180万户家庭面临沿海洪水和侵蚀的风险。极端事件已经对沿海地区产生了非常重大的影响，2013/14年冬季沿海洪灾造成的损失超过5亿GB，直接经济影响平均每年超过2.6亿GB。在下个世纪，沿海灾害将会增加，主要是由不可避免的海平面上升推动的。与此同时，英国承诺到2050年实现净零碳排放。因此，至关重要的是要确保英国海岸得到管理，以确保海岸保护对未来气候具有弹性，并实现净零抱负。通过在目前计划的所有地点维持坚硬的灰色防御来保护海岸不太可能具有成本效益。因此，可持续的海岸管理和适应将需要更广泛的行动，并更多地使用与自然相适应的、多功能的、可以带来额外好处的更软的“绿色”解决方案。然而，绿色解决方案的采用仍然参差不齐。根据气候变化委员会的数据，接受有管理的调整的速度慢了五倍，无法实现2030年的既定目标。原因是复杂的，跨越了整个人类-环境系统。基于自然的解决方案往往缺乏公众舆论的支持，并遇到社会阻力。尽管取消了对坚固防御的长期承诺，但由于高昂的前期成本、难以评估所提供的多种共同利益以及未来环境和社会经济预测固有的不确定性，绿色方法的经济理由仍然不确定。用于支持当今沿海管理和政策制定的框架(如海岸线管理计划)没有提供全面和一致的办法来解决这些问题。后果是这些政策方法的有效性降低。因此，要实现英国海岸的可持续管理，将需要新的框架，该框架涵盖整个复杂的人类-环境系统，并提供全面的科学基础，以确定不同的价值系统如何与决策制定相互作用，气候变化将如何影响沿海生态系统服务，以及决策支持工具如何结合多种不确定性。CoOPT将提供一个新的集成和跨学科的基于系统的框架，将有效支持海岸和海岸线管理中从硬性“灰色”防御到软性“绿色”解决方案所需的过渡。这一框架将首次将复杂的沿海社会生态系统的概念表述、气候变化下沿海生态系统服务的量化评估以及社会观念和价值观如何影响这两个要素的特征结合起来。我们的新框架将与国家、地区和地方利益攸关方合作，在英国的四个案例研究中进行演示。这将为支持沿海管理和政策制定提供一个可扩展和适应性强的解决方案。COP-OPT是与对实施和交付沿海和海岸线管理至关重要的项目伙伴(如环境署、威尔士自然资源公司、苏格兰自然资源公司、沿海团体)共同设计的，将满足他们的具体需要，包括制定全面的成本效益分析，并在必要的政策变化时就行动计划提出建议。通过支持对复杂的沿海人类-环境系统进行更全面和跨学科的描述，海岸科学合作项目将进一步惠及广泛的沿海科学基础。

Sea and society interact most strongly at the coast where communities both benefit from and are threatened by the marine environment. Coastal flooding was the second highest risk after pandemic flu on the UK government's risk register in 2017. Over 1.8 million homes are at risk of coastal flooding and erosion in England alone. Extreme events already have very significant impacts at the coast, with the damage due to coastal flooding during the winter 2013/14 in excess of £500 million, and direct economic impacts exceeding £260 million per year on average. Coastal hazards will be increasing over the next century primarily driven by unavoidable sea level rise. At the same time, the UK is committed to reach net zero carbon emissions by 2050. It is therefore essential to ensure that UK coasts are managed so that coastal protection is resilient to future climate and the net zero ambition is achieved. Protecting the coast by maintaining hard 'grey' defences in all locations currently planned is unlikely to be cost-effective. Sustainable coastal management and adaptation will therefore require a broader range of actions, and greater use of softer 'green' solutions that work with nature, are multifunctional, and can deliver additional benefits.Examples already exist and include managed realignment, restoration of coastal habitats, and sand mega-nourishments. However, the uptake of green solutions remains patchy. According to the Committee on Climate Change, the uptake of managed realignment is five times too slow to meet the stated 2030 target. Reasons are complex and span the whole human-environment system. Nature-based solutions often lack support from public opinion and meet social resistance. Despite removing long-term commitment to hard defences, the economic justification for green approaches remains uncertain due to high upfront costs, difficulty in valuing the multiple co-benefits offered, and uncertainties inherent to future environmental and socio-economic projections. The frameworks used to support present day coastal management and policy making (e.g. Shoreline Management Plans) do not provide comprehensive and consistent approaches to resolve these issues. Consequences are that the effectiveness of these policy approaches is reduced. Delivering sustainable management of UK coasts will therefore require new frameworks that embrace the whole complex human-environment system and provide thorough scientific underpinning to determine how different value systems interact with decision making, how climate change will impact coastal ecosystem services, and how decision support tools can combine multiple uncertainties.Co-Opt will deliver a new integrated and interdisciplinary system-based framework that will effectively support the required transition from hard 'grey' defences to softer 'green' solutions in coastal and shoreline management. This framework will combine for the first time a conceptual representation of the complex coastal socio-ecological system, quantitative valuation of coastal ecosystem services under a changing climate, and the characterisation of how social perceptions and values influence both previous elements. Our new framework will be demonstrated for four case studies in the UK in collaboration with national, regional, and local stakeholders. This will provide a scalable and adaptive solution to support coastal management and policy development. Co-Opt has been co-designed with project partners essential to the implementation and delivery of coastal and shoreline management (e.g. Environment Agency, Natural Resources Wales, NatureScot, coastal groups) and will address their specific needs including development of thorough cost-benefit analyses and recommendations for action plans when preferred policy changes. Co-Opt will further benefit the broad coastal science base by supporting more integrated and interdisciplinary characterisation of the complex coastal human-environment system.