RESUMEN
Improper municipal solid waste (MSW) management contributes to greenhouse gas emissions, necessitating emissions reduction strategies such as waste reduction, recycling, and composting to move towards a more sustainable, low-carbon future. Machine learning models are applied for MSW-related trend prediction to provide insights on future waste generation or carbon emissions trends and assist the formulation of effective low-carbon policies. Yet, the existing machine learning models are diverse and scattered. This inconsistency poses challenges for researchers in the MSW domain who seek to identify and optimize the machine learning techniques and configurations for their applications. This systematic review focuses on MSW-related trend prediction using the most frequently applied machine learning model, artificial neural network (ANN), while addressing potential methodological improvements for reducing prediction uncertainty. Thirty-two papers published from 2013 to 2023 are included in this review, all applying ANN for MSW-related trend prediction. Observing a decrease in the size of data samples used in studies from daily to annual timescales, the summarized statistics suggest that well-performing ANN models can still be developed with approximately 33 annual data samples. This indicates promising opportunities for modeling macroscale greenhouse gas emissions in future works. Existing literature commonly used the grid search (manual) technique for hyperparameter (e.g., learning rate, number of neurons) optimization and should explore more time-efficient automated optimization techniques. Since there are no one-size-fits-all performance indicators, it is crucial to report the model's predictive performance based on more than one performance indicator and examine its uncertainty. The predictive performance of newly-developed integrated models should also be benchmarked to show performance improvement clearly and promote similar applications in future works. The review analyzed the shortcomings, best practices, and prospects of ANNs for MSW-related trend predictions, supporting the realization of practical applications of ANNs to enhance waste management practices and reduce carbon emissions.
Asunto(s)
Redes Neurales de la Computación , Residuos Sólidos , Administración de Residuos , Contaminantes Atmosféricos/análisis , Carbono , Gases de Efecto Invernadero/análisis , Aprendizaje Automático , Eliminación de Residuos/métodos , Residuos Sólidos/análisis , Administración de Residuos/métodosRESUMEN
Although large-scale solar (LSS) is a promising renewable energy technology, it causes adverse impacts on the ecosystem, human health, and resource depletion throughout its upstream (i.e., raw material extraction to solar panel production) and downstream (i.e., plant demolition and waste management) processes. The LSS operational performance also fluctuates due to meteorological conditions, leading to uncertainty in electricity generation and raising concerns about its overall environmental performance. Hitherto, there has been no evidence-backed study that evaluates the ecological sustainability of LSS with the consideration of meteorological uncertainties. In this study, a novel integrated Life Cycle Assessment (LCA) and Artificial Neural Network (ANN) framework is developed to forecast the meteorological impacts on LSS's electricity generation and its life cycle environmental sustainability. For LCA, 18 impact categories and three damage categories are characterised and assessed by ReCiPe 2016 via SimaPro v. 9.1. For ANN, a feedforward neural network is applied via Neural Designer 5.9.3. Taking an LSS plant in Malaysia as a case study, the photovoltaic panel production stage contributes the highest environmental impact in LSS (30 % of human health, 30 % of ecosystem quality, and 34 % of resource scarcity). Aluminium recycling reduces by 10 % for human health, 10 % for ecosystem quality, and 9 % for resource scarcity. The emissions avoided by the forecasted LSS-generated electricity offset the environmental burden for human health, ecosystem quality, and resource scarcity 12-68 times, 13-73 times, and 18-98 times, respectively. The developed ANN-LCA framework can provide LSS stakeholders with data-backed insights to effectively design an environmentally conscious LSS facility, considering meteorological influences.
RESUMEN
No global analysis has considered the warming that could be averted through improved solid waste management and how much that could contribute to meeting the Paris Agreement's 1.5° and 2°C pathway goals or the terms of the Global Methane Pledge. With our estimated global solid waste generation of 2.56 to 3.33 billion tonnes by 2050, implementing abrupt technical and behavioral changes could result in a net-zero warming solid waste system relative to 2020, leading to 11 to 27 billion tonnes of carbon dioxide warming-equivalent emissions under the temperature limits. These changes, however, require accelerated adoption within 9 to 17 years (by 2033 to 2041) to align with the Global Methane Pledge. Rapidly reducing methane, carbon dioxide, and nitrous oxide emissions is necessary to maximize the short-term climate benefits and stop the ongoing temperature rise.
RESUMEN
The COVID-19 pandemic caused profound impacts on the global economy, resulting in a sharp drop in carbon emissions as energy demand fell. The emissions reduction due to past extreme events often follows with a rebound after the economy recovers, but the pandemic's impacts on the long-term carbon emissions trend remain unknown. This study forecasts the carbon emissions of Group of Seven (G7) as developed countries and Emerging Seven (E7) as developing countries using socioeconomic indicators and artificial intelligence-powered predictive analytics to assess the pandemic's impacts on the long-term carbon trajectory curve and their progress toward achieving the Paris Agreement goals. Most E7's carbon emissions have strong positive correlations (> 0.8) with the socioeconomic indicators, whereas most G7's correlate negatively (> 0.6) due to their decoupled economic growth from carbon emissions. The forecasts show higher growth rates in the E7's carbon emissions after the rebound in the pandemic scenario compared to the pandemic-free scenario, while the impact on the G7's carbon emissions is negligible. The overall impact of the pandemic outbreak on long-term carbon emissions is small. Still, its short-term positive impact on the environment should not be misunderstood, and stringent emissions reduction policies must be implemented urgently to ensure the achievement of Paris Agreement goals. Graphical Abstract: Research methodology for assessing the pandemic's impacts on the G7 and E7 countries' long-term carbon trajectory curve. Supplementary Information: The online version contains supplementary material available at 10.1007/s10098-023-02508-0.