Strengthening international cooperation on sustainable urbanisation: nature-based solutions for restoration and rehabilitation of urban ecosystems Actions should develop models, tools, decision support systems, methodologies, strategies, guidelines, standards and approaches for the design, construction, deployment and monitoring of nature-based solutions and restoration, prevention of further degradation, rehabilitation and maintenance measures for urban and peri-urban ecosystems and the ecological coherence and integrity of cities. Actions should review and capitalise upon existing experiences and good practices in Europe and (for option a) China or (for option b) CELAC. The strategies and tools should be part of an integrated and ecologically coherent urban planning and city-making process that would secure a fair and equitable distribution of benefits from the restored urban ecology and limit its exposure to environmental stresses. Methodologies, schemes and indicators should be developed to allow for the assessment of the cost-effectiveness of the restoration measures, also accounting for their possible negative effects. They should account for the totality of the benefits delivered by the restored ecosystems in terms of, for example, enhancing cities’ climate-proofing and resilience, enhancing mitigation options, improving human health and well-being, reducing inequalities and reducing cities’ environmental footprint. Actions should also dedicate efforts to awareness raising, outreach activities and education of citizens, including school children about the benefits of nature for their social, economic and cultural well-being.Actions should bring together European and – depending on the option chosen – Chinese or CELAC research partners, government agencies and urban authorities, private sector and civil society with relevant expertise and competence and foster participatory engagement in urban ecological restoration actions. Further to the eligibility and admissibility conditions applicable to this topic, proposals are encouraged to ensure, to the extent possible, an appropriate balance in terms of effort and/or number of partners between the EU and the international partners, which would correspond to their respective ambition, objectives and envisaged work. This would enhance the impact of the actions and the mutual benefits for both the EU and the international partners.In line with the strategy for EU international cooperation in research and innovation (COM(2012)497), international cooperation is encouraged. Proposals should pay attention to the special call conditions for this topic.To ensure that knowledge, evidence and capacity developed within the framework of this topic covers an as broad range of conditions and urban contexts as possible across Europe, urban and peri-urban areas and ecosystems funded through projects under sub-topic a) are not invited to sub-topic b). Exceptions may be made on a case-by-case basis, provided that applicants can duly and convincingly justify the added value – in terms of additional knowledge, evidence and capacity regarding nature-based solutions for restoration and rehabilitation of urban ecosystems – of addressing the same area(s) under sub-topic b) in addition to them being covered through a project funded under sub-topic a). The appropriate use of Horizon 2020 resources in funding such cases will be assessed during the evaluations and the potential granting process.The participation of social sciences and humanities disciplines, addressing also the gender dimension, is crucial to properly address this topic. Cooperation and synergies with the activities undertaken within the Covenant of Mayors initiative for Climate and Energy[[www.covenantofmayors.eu]] initiative (supported by the EC) should be sought where appropriate.Actions should address only one of the following sub-topics:a) Strengthening EU-China collaboration (2018)This topic is part of the EU-China flagship initiative on Environment and Sustainable Urbanisation which aims at promoting substantial coordinated and balanced research and innovation cooperation between the EU and China.China-based participants have the possibility to apply for funding under the Chinese co-funding mechanism and other Chinese sources[[See http://ec.europa.eu/research/participants/docs/h2020-funding-guide/cross-cutting-issues/international-cooperation_en.htm#support-non-eu-countries]].b) Strengthening EU-CELAC collaboration (2019)The possibility for participants from some CELAC countries to apply for funding under national co-funding mechanism should be explored[[See http://ec.europa.eu/research/participants/docs/h2020-funding-guide/cross-cutting-issues/international-cooperation_en.htm#support-non-eu-countries]].The Commission considers that proposals requesting a contribution from the EU in the range of EUR 5 million would allow this specific challenge to be addressed appropriately. Nonetheless, this does not preclude submission and selection of proposals requesting other amounts. Unsustainable, non-resilient urbanisation patterns, the expansion or neglect of urban areas have caused the fragmentation, depletion and destruction of habitats, biodiversity loss and the degradation of ecosystems and their services. Increasing connectivity between existing, modified and new ecosystems and restoring and rehabilitating them within cities and at the urban-rural interface through nature-based solutions[[A definition is provided in the introductory text of this Work Programme]], is necessary to enhance ecosystem resilience and adaptive capacity to cope with the effects of climate and global changes and to enable ecosystems to deliver their services for more liveable, healthier and resilient cities. The project results are expected to contribute to:restored and functioning urban ecosystems with an enhanced capacity to deliver their services;making a business and investment case for nature-based solutions on the basis of increased evidence about the positive and negative impacts from restored urban ecosystems with regards to urban liveability, climate change resilience, social inclusion, urban regeneration, public health and well-being;guidelines for cost effective urban ecosystem restoration and ecological rehabilitation measures and new planning approaches and methods.