Strategies for reducing greenhouse gas emissions from municipal solid waste management in Pakistan

Unlocking the significant worldwide potential of better waste and resource management for climate mitigation: with particular focus on the Global South

Numbers do matter; the Intergovernmental Panel on Climate Change (IPCC)'s 2010 data that the waste sector is responsible for just 3% of global greenhouse gas (GHG) emissions has led to the misperception that solid waste management (SWM) has little to contribute to climate mitigation. Global efforts to control methane emissions and divert organic waste from landfills had already reduced direct emissions. But end-of-pipe SWM has also been evolving into more circular waste and resource management, with indirect GHG savings from the 3Rs (reduce, reuse, recycle) which IPCC accounts for elsewhere in the economy. The evidence compiled here on both direct emissions and indirect savings demonstrates with high confidence that better waste and resource management can make a significant contribution to climate mitigation, and must form a core part of every country's nationally determined contribution. Even the most advanced countries can still achieve much from the 3Rs. In the Global South, the challenge of extending waste collection to all and stopping open dumping and burning (sustainable development goal 11.6.1), essential to improve public health, can be turned into a huge opportunity. Moving early to divert waste from landfill by separation at source and collecting clean organic and dry recycling fractions, will mitigate global GHG emissions, slash ocean plastics and create decent livelihoods. But this can only happen with targeted climate, plastics and extended producer responsibility finance; and help to local communities to help themselves.

Considerations on the methane correction factor and fraction of methane parameters in the IPCC first-order decay model for active aeration landfills

Understanding the behavior of organic carbon in municipal solid waste landfills is a major challenge for estimating methane (CH4) emissions using the Intergovernmental Panel on Climate Change (IPCC) first-order decay (FOD) model. According to the IPCC guidelines, the default values of CH4 correction factor (MCF) and fraction of CH4 (F) for active aeration landfills are set as 0.4 and 0.5, respectively. However, whether it is reasonable to apply the default values of MCF and F to active aeration landfills is questionable. This study aims to estimate the MCF and develop a method to determine the F value for active aeration landfills. In this investigation, three landfill sites were operated as active aeration landfills to estimate the MCF and the F. The study results indicate that MCF values were lower than the default value of 0.4 provided in the IPCC guidelines under aerobic conditions with a CH4 concentration of less than 5%. According to the carbon balance analyses, there was a mismatch between the theoretical CH4/CO2 ratio based on the F default value of 0.5 and the measured CH4/CO2 ratio. Using the F calculation method proposed in this study, the theoretical CH4/CO2 ratio and the measured CH4/CO2 ratio was calculated equally. The F values during air injection ranged from 0.25 to 0.93 at three landfill sites, suggesting that adapting the F default value of 0.5 for active aeration landfills may lead to significant errors in the estimation of CH4 emissions using the IPCC FOD model.

Land footprint and GHG emissions from global food loss

BACKGROUND

Efficient land use represents a global challenge in the context of high levels of food loss (FL) and waste (FLW) and increasing greenhouse gas (GHG) emissions from global agricultural activities. This study aimed to estimate the land footprint (LF) associated with FL worldwide. It also estimated the GHG emissions from crop residues and their burning, and their relationship with food loss for the main crops worldwide. The study analyzed data from the Food and Agriculture Organization of the United Nations (FAO) regarding land use, FL, and global GHG emissions from crop residues.

RESULTS

The findings suggest that the average LF associated with FL worldwide is about 69 million ha per year, and the main food items responsible for most of the LF associated with FL are maize, wheat, and rice. The annual average emissions derived from burning crop residues of FL are 48.8 kilotons year^-1 of CH₄ and 1.26 kilotons year^-1 of N₂ O, and the emission of N₂ O derived from crop residues of FL is about 24.1 kilotons year^-1 , considering the three crops.

CONCLUSION

Food loss implies high levels of LF and GHG emissions, reinforcing the need for proper public and private initiatives worldwide to reduce FL and waste (FLW). Organizations such as the FAO and the Organisation for Economic Co-operation and Development (OECD) should incorporate indicators regarding FLW reduction to evaluate and monitor countries' performance. An international agreement also needs to be addressed to engage the world's nations in the reduction of FLW levels. © 2023 Society of Chemical Industry.

A facilitating framework for a developing country to adopt smart waste management in the context of circular economy

To achieve higher standards of sustainability, the waste management sector now requires the incorporation of circular economy (CE) principles. However, an easy transition toward the particular goal would require the use of smart waste technologies. To achieve the aforementioned goal, this study aims to provide a facilitating framework for the adoption of smart waste management in the context of CE for Pakistan. To help Pakistan transition toward the new paradigm, a total of 16 critical facilitators are evaluated based on five distinctive criteria using a novel fuzzy hybrid multi-criteria decision-making (MCDM) approach. The hybrid MCDM approach includes fuzzy Stepwise Weight Assessment Ratio Analysis (SWARA) for allocating weights to the determined criteria; whereas, the fuzzy VIšekriterijumsko kompromisno rangiranje (VIKOR) approach is used to rank the critical facilitators adopted from the secondary literature. The fuzzy approach in both cases is to deal with any kind of uncertainty during the data collection process. Based on the achieved results, the study suggests that before the application of smart waste technologies in the country, Pakistan should first focus on devising regulations that effectively address the mismanagement of waste produced in the country. Also, the industries in the country need to become more responsible and should adopt environmental management systems that foster waste minimization. Lastly, the country in the third phase should focus on the wide application of digitalization both in the streams of ICT and IoT, for collecting, sharing, and receiving waste data. The study further provides policy recommendations to the respective stakeholders that will help the country achieve zero-waste CE.