Modelling the Nexus of municipal solid waste sector for climate resilience and adaptation to nature-based solutions: A case study of Pakistan

Abstract

Municipal solid waste management is a major concern in developing economies, requiring collective international efforts to achieve carbon neutrality by diverting waste from disposal facilities. This study aims to highlight the importance of the waste sector as it has the potential to significantly contribute to climate change and its toxicity impact on the local ecosystem. Out of the total municipal solid waste generated, only 78 % is collected, either open dumped or thrown in sanitary landfills. The waste sector's ecological impact value is calculated for the Earth's regions, and it is very high at >50 % in Africa, Asia, Latin America and the Caribbean. This sectoral impact value is mainly responsible for greenhouse gas emissions and degradation of the local ecosystem health. Current business‒as‒usual practices attribute 3.42 % of global emissions to the waste sector. Various scenarios are developed based on waste diversion and related emissions modelling, and it is found that scenarios 3 and 4 will support the policymakers of the regions in attaining zero carbon footprints in the waste sector. Our findings conclude that cost-effective nature-based solutions will help low‒income countries reduce emissions from disposal sites and significantly improve the local ecosystem's health. Developed economies have established robust waste‒handling policies and implementation frameworks, and there is a need for collaboration and knowledge sharing with developing economies at the regional level to sustain the sector globally.

Keywords: Climate resilience; Ecological impact value (WS-EIV); Nature-based solutions; Waste & ecosystems; Waste management.

Graphical abstract

Fig. 1

Theme and novelty of the study/research work.

Fig. 2

Research formwork, areas and assumptions used for scenario development to perform environmental modelling.

Fig. 3

Scope of work of the study.

Fig. 4

The world population and waste generation trend over the period. (A) Regional population and waste generation. (B) Global population and waste generation projections.

Fig. 5

Assumptions used in scenario development. (A) Business as usual Scenario. (B) Landfill gas recovery under business as usual. (C) Scenarion-1. (D) Scenario-2. (E) Scenario-3. (F) Scenario-4.

Fig. 6

Environmental model for scenarios from the perspective of carbon neutrality. (A) GHG emissions value from each scenario. (B) BC emissions value from each scenario. (C) Geographic representation of emissions value in business as usual. (D) Geographic representation of emissions value in Scenario-1. (E) Geographic representation of emissions value in Scenario-2. (f) Geographic representation of emissions value in Scenario-3. (G) Geographic representation of emissions value in Scenario-4. (H) Implementation timelines for execution of proposed scenarios.

Fig. 7

Regional sensitivity analysis for various scenarios. (A) Analysis for Asia (B) Analysis for Africa (C) Analysis for LAC. (D) Analysis for NA. (E) Analysis for Oceania region.

Fig. 8

Economic analysis of various waste treatments and related climate impacts.

Fig. 9

Waste sector and climatic impact. (A) Per capita GHG emissions from the waste sector. (B) The correlation between temperature and related seal level rise from MSW sector's related emissions under S-BAU.

Fig. 10

MSW-related ecotoxicity: (A) Graphical presentation of global waste generation over the period under business as usual. (B) The waste sector ecological impact value under business as usual. (C) The waste sector ecological impact value for each scenario. (D) Chemical composition of leachate at Sahiwal disposal facility.

Fig. 11

Funding sources, amount and tonnage collection cost of waste management companies.

Fig. 12

MRF in Sahiwal city. (A) Recovered recyclables from MSW. (B) Organic compost manufactured from MSW. (C) Compost brand for marketing in agriculture sector.

Fig. 13

Proposed regional waste handling in Punjab. (A) Waste processing and recovery targets for treatment (B) Reduction in GHG emissions from waste diversion and potential carbon credits (C) Costing of landfills, transfer station and material recovery for the period of 10 years (D) Sites identified for establishment of transfer station cum MRF at district level in Punjab.

Fig. 14

Phytoremediation initiative in Lahore city. (A) Mehmood Booti dumpsite before phytocapping. (B) Site preparation for rehabilitation. (C) Rehabilitation of old dumpsite with phytocapping technique. (D) Comparison of gas emission from disposal sites.