A system dynamics-based scenario analysis of residential solid waste management in Kisumu, Kenya

Managing the low carbon transition pathways through solid waste electricity

The potential of solid waste as an energy source is clear, owing to its wide availability and renewable properties, which provide a critical answer for energy security. This can be especially effective in reducing the environmental impact of fossil fuels. Countries that rely heavily on coal should examine alternatives such as electricity from solid waste to provide a constant energy supply while also contributing to atmospheric restoration. In this regards, Low Emissions Analysis Platform (LEAP) is used for simulation the entire energy system in Pakistan and forecasted its capital cost and future CO2 emissions in relation to the use of renewable and fossil fuel resources under the different growth rates of solid waste projects like 20%, 30% and 40% for the study period 2023-2053. The results revealed that, 1402.97 TWh units of energy are generated to meet the total energy demand of 1193.93 TWh until 2053. The share of solid waste based electricity in total energy mix is increasing from a mere 0.81% in 2023 to around 9.44% by 2053 under the 20% growth rate, which then increase to 39.67% by 2053 under the 30% growth rate and further increases to 78.33% by 2053 under the 40% growth rate. It is suggested that 40% growth rate for solid waste based electricity projects is suitable for Pakistan until 2053 because under this condition, renewable sources contributes 95.2% and fossil fuels contributed 4.47% in the total energy mix of Pakistan. Hence, CO2 emissions are reduced from 148.26 million metric tons to 35.46 million metric tons until 2053 but capital cost is increased from 13.23 b$ in 2023 to 363.11 b$ by 2053.

Forecasting the effects of municipal solid plastic waste generation and streaming using system dynamics: A case study in Dubai

To effectively manage municipal solid plastic waste (MSPW), municipalities need to select an appropriate combination of policies and technologies. Numerous policies and technologies are inputs for this selection problem, whereas decision-makers pursue several economic and environmental outcomes. The MSPW flow-controlling variables serve as an intermediary between the inputs and outputs of this selection problem. Examples of the flow-controlling, mediating variables include the source-separated and incinerated MSPW percentages. This study proposes a system dynamics (SD) model that anticipates the influence of these mediating variables on multiple outputs. The outputs include volumes of four MSPW streams and three sustainability-related externalities: GHG emissions reduction, net energy savings, and net profit. Using the SD model, decision-makers can determine the best levels for the mediating variables based on the desired outputs. Consequently, decision-makers can identify the MSPW system stages at which they must choose policies and technologies. Additionally, the values of the mediating variables will help clarify for decision-makers how strict they should be when imposing policies and how much to invest in technologies at the selected MSPW system stages. The SD model is applied to Dubai's MSPW problem. A sensitivity analysis experiment conducted on Dubai's MSPW system demonstrates that the earlier an action is taken, the better the results will be achieved. Consequently, reducing municipal solid waste should take priority, followed by increasing source separation, then post-separation, and finally, incineration with energy recovery. The results of another experiment employing a full factorial design with four mediating variables indicate that recycling would impact GHG emissions and energy reduction values more than incineration with energy recovery. However, these savings are global in nature.

Environmental Sustainability Impacts of Solid Waste Management Practices in the Global South

Solid waste management (SWM) is one of the key responsibilities of city administrators and one of the effective proxies for good governance. Effective SWM mitigates adverse health and environmental impacts, conserves resources, and improves the livability of cities. However, unsustainable SWM practices, exacerbated by rapid urbanization and financial and institutional limitations, negatively impact public health and environmental sustainability. This review article assesses the human and environmental health impacts of SWM practices in the Global South cities that are the future of global urbanization. The study employs desktop research methodology based on in-depth analysis of secondary data and literature, including official documents and published articles. It finds that the commonplace SWM practices include mixing household and commercial garbage with hazardous waste during storage and handling. While waste storage is largely in old or poorly managed facilities such as storage containers, the transportation system is often deficient and informal. The disposal methods are predominantly via uncontrolled dumping, open-air incinerators, and landfills. The negative impacts of such practices include air and water pollution, land degradation, emissions of methane and hazardous leachate, and climate change. These impacts impose significant environmental and public health costs on residents with marginalized social groups mostly affected. The paper concludes with recommendations for mitigating the public and environmental health risks associated with the existing SWM practices in the Global South.

Quantitative Evaluation of Waste Separation Management Policies in the Yangtze River Delta Based on the PMC Index Model

Numerous policies have been formulated and implemented to strengthen waste separation management activities in many countries. Waste separation management policies (WSMPs) must be evaluated as the precondition for reducing deviations from policy implementation and improving waste separation performance. Based on text mining technology and the construction of a policy modeling consistency (PMC) index model, we conducted a quantitative evaluation of 22 WSMPs issued by central governmental departments and provinces in the Yangtze River Delta, China from 2013 to 2021 and analyzed their optimization paths. The results suggest that the PMC index of the selected WSMPs has an upward trend. The average PMC index of 22 WSMPs was 6.906, indicating good quality in the policy texts. The PMC index identified seven, nine, five, and one of the policies as being perfect, excellent, good, and acceptable, respectively. The characteristics of WSMPs were further illustrated through PMC surface charts. Based on this, optimization paths for WSMPs with lower PMC indexes are proposed, which indicate that existing WSMPs have great potential for optimization in terms of harsher constraint regulations, context-appropriate incentives, and cultivation of market participants. Finally, this study provides a beneficial reference for similar cities or countries to improve their performance in the management of waste separation and environmental protection.

The wicked problem of waste management: An attention-based analysis of stakeholder behaviours

Surging amounts of waste are reported globally and especially in lower-income countries, with negative consequences for health and the environment. Increasing concern has been raised for the limited progress achieved in practice by diverse sets of policies and programmes. Waste management is a wicked problem characterised by multilayered interdependencies, complex social dynamics and webs of stakeholders. Interactions among these generate unpredictable outcomes that can be missed by decision makers through their understanding and framing of their context. This article aims to identify possible sources of persistent problems by focussing on what captures, shapes and limits the attention of stakeholders and decision-makers, drawing on the attention-based view from organisation theory. The theory describes the process through which issues and opportunities are noticed and how these are translated into actions, by focussing on the influencers at the individual, organisational and context scale. Views on issues and opportunities for waste management were collected in a series of fieldwork activities from 60 participants representing seven main types of stakeholders in the typical lower-middle income Kenyan city of Kisumu. Through a thematic analysis guided by the attention-based view, we identified patterns and misalignment of views, especially between government, community-based organisations and residents, which may contribute to persistent waste problems in Kisumu. Some point to detrimental waste handling practices, from separation to collection and treatment, as the main cause of issues. For others, these practices are due to a poor control of such practices and enforcement of the law. This study's major theoretical contribution is extending the application of attention theory to multi-stakeholder problems and to non-formalized organisations, namely residents and to the new field of waste management. This novel lens contributes a greater understanding of waste issues and their management in Africa that is relevant to policy and future research. By revealing the "wickedness" of the waste problem, we point to the need for a holistic and systems-based policy approach to limit further unintended consequences.