Global Waste Management Outlook

The Global Waste Management Outlook, a collective effort of the United Nations Environment Programme and the International Waste Management Association, is a pioneering scientific global assessment on the state of waste management and a call for action to the international community. Prepared as a follow up to the Rio+20 Summit and as a response to UNEP Governing Council decision GC 27/12, the document establishes the rationale and the tools for taking a holistic approach towards waste management and recognizing waste and resource management as a significant contributor to sustainable development and climate change mitigation. To complement the Sustainable Development Goals of the Post-2015 Development Agenda, the Outlook sets forth Global Waste Management Goals and a Global Call to Action to achieve those goals

Trends in climate adaptation solutions for mountain regions

This study addresses the critical need for documented adaptation progress in mountain regions by reviewing recently implemented or ongoing adaptation solutions collected from the Adaptation at Altitude Solutions Portal (A@A Solution Portal). Using a data driven approach, the research explores the characteristics, feasibility, and transformative potential of these solutions. Findings reveal a predominant focus on addressing droughts and floods, aligning with the IPCC’s emphasis on water-related impacts in mountains. Notably, watershed management practices emerge as popular solutions, showcasing their capacity to address multiple concerns beyond climate impacts. Education and awareness, along with land use practices, dominate the types of solutions, reflecting their positive impact on project acceptability and low associated risk of maladaptation. Agricultural land and forests are the main ecosystems where solutions are reported, with an evident association with education and awareness and land use change solutions. Most SDGs and Sendai targets are found to be addressed by the solutions emphasising the importance of documenting project experiences as way to bridge previously reported gaps between policy frameworks and on-the-ground implementation. Despite community involvement being high in many of the solutions, challenges such as gender inequality persists. While solutions often demonstrate local relevance and depth of change, upscaling remains challenging, with limited evidence of mainstreaming and replication. Sustainability criteria are moderately met, incorporating inclusive decision-making but with uncertainty regarding long-term plans. Furthermore, findings underscore the significance of co-developing and maintaining adaptation solution portals, illustrating how this approach enriches our understanding of adaptation progress in mountains. Moreover, this research contributes to broadening the scope of systematic adaptation assessments by providing a nuanced perspective that integrates local needs and diverse knowledge systems. In essence, this study makes a valuable contribution to the evolving landscape of adaptation research, emphasizing the importance of practical insights and collaborative efforts to address the complex challenges posed by climate-related impacts and corresponding adaptation efforts

Pattern Formation of the Attraction-Repulsion Keller-Segel System

In this paper, the pattern formation of the attraction-repulsion Keller-Segel (ARKS) system is studied analytically and numerically. By the Hopf bifurcation theorem as well as the local and global bifurcation theorem, we rigorously establish the existence of time-periodic patterns and steady state patterns for the ARKS model in the full parameter regimes, which are identified by a linear stability analysis. We also show that when the chemotactic attraction is strong, a spiky steady state pattern can develop. Explicit time-periodic rippling wave patterns and spiky steady state patterns are obtained numerically by carefully selecting parameter values based on our theoretical results. The study in the paper asserts that chemotactic competitive interaction between attraction and repulsion can produce periodic patterns which are impossible for the chemotaxis model with a single chemical (either chemo-attractant or chemo-repellent)

A Nested Variational Time Discretization for Parametric Anisotropic Willmore Flow

A variational time discretization of anisotropic Willmore flow combined with a spatial discretization via piecewise affine finite elements is presented. Here, both the energy and the metric underlying the gradient flow are anisotropic, which in particular ensures that Wulff shapes are invariant up to scaling under the gradient flow. In each time step of the gradient flow a nested optimization problem has to be solved. Thereby, an outer variational problem reflects the time discretization of the actual Willmore flow and involves an approximate anisotropic L 2-distance between two consecutive time steps and a fully implicit approximation of the anisotropic Willmore energy. The anisotropic mean curvature needed to evaluate the energy integrand is replaced by the time discrete, approximate speed from an inner, fully implicit variational scheme for anisotropic mean curvature motion. To solve the nested optimization problem a Newton method for the associated Lagrangian is applied. Computational results for the evolution of curves underline the robustness of the new scheme, in particular with respect to large time steps.