Assessing the global warming potential impact of organic fertilizer strategies in rice cultivation in Sri Lanka.

Rice is the staple food in Sri Lanka, and over 15% of the national land is allocated for rice cultivation. Greenhouse gas (GHG) emissions from rice fields account for 10% of national GHG emissions. The country has committed to reducing its emissions by 14.5% between 2010 and 2030 and achieving net zero emissions by 2060. In 2021, the country banned agro-fertilizer imports and opted for organic fertilizers, leading to a notable decrease in production and posing challenges to food security. However, the impact of adopting compost fertilizers alone remains unexplored. This study evaluated the global warming impact of two organic fertilizer strategies: switching to compost fertilizer instead of urea and applying rice straw compost instead of retaining crop residue. We applied the Denitrification and Decomposition model (DNDC 95) to rice field management data from Sri Lanka's Mahaweli H agricultural region. Simulations suggest that both strategies would increase the global warming potential of rice fields, mainly owing to elevated N2O emissions. This outweighs the mitigation benefits of avoiding crop residue retention and adding organic carbon through compost. Overall, our results point to the potential risk of shifting exclusively to compost-based fertilizers.

A study on GHG emission assessment in agricultural areas in Sri Lanka: the case of Mahaweli H agricultural region.

Agricultural activities contribute 7% to Sri Lanka's economy and account for 20% of the national greenhouse gas (GHG) emissions. The country aims to achieve zero net emissions by 2060. This study was aimed at assessing the present state of agricultural emissions and identifying mitigation strategies. The assessment involved estimating agricultural net GHG emissions from non-mechanical sources in the Mahaweli H region, Sri Lanka, in 2018 using the Intergovernmental Panel on Climate Change (IPCC 2019) guidelines. New indicators were developed to measure emissions for major crops and livestock and used to show the flow of carbon and nitrogen. The region's agricultural emissions were estimated to be 162,318 t CO2eq y-1, of which 48% was from rice field methane (CH4) emissions, 32% from soil nitrogen oxide emissions, and 11% from livestock enteric CH4 emissions. Biomass carbon accumulation offset 16% of the total emissions. Rice crops exhibited the highest emission intensity of 4.77 t CO2eq ha-1 y-1, while coconut crop had the highest abatement potential of 15.58 t CO2eq ha-1 y-1. Approximately 1.86% of the carbon input to the agricultural system was released as carbon-containing GHG (CO2 and CH4), whereas 1.18% of the nitrogen input was released as nitrous oxide. The findings of this study suggest extensive adaptations of agricultural carbon sequestration strategies and increased nitrogen use efficiency to achieve GHG mitigation targets. The emission intensity indicators derived from this study can be used for regional agricultural land use planning to maintain designated levels of emissions and implement low-emission farms.

Environmental and economic performances of municipal solid waste management strategies based on LCA method: A case study of kinshasa.

Like many populated urban agglomerations in Africa, Kinshasa, the capital of Democratic Republic of Congo, faces several challenges to manage its exponentially growing Municipal Solid Waste. With its 12, 000, 000 people daily generating 7800 tons of Municipal Solid waste, the city still struggles with basic services such as waste collection and sanitary landfill. This causes major social, environmental and health related issues. With the aim of contributing to the implementation of a better management system in Kinshasa, this study evaluates the environmental impact and the cost of the existing waste management framework and proposes 6 alternative scenarios. Each scenario attempts to optimize Greenhouse gas emissions and cost, using the Life Cycle Assessment approach. Results show that the current municipal solid waste management in Kinshasa city emits 640,673 tons of CO2 equivalent per year and costs a total of 17, 776, 169.78USD yearly. Focusing on increasing waste collection coverage and recycling activities in the proposed 6 scenarios, scenario 4 where all municipal solid waste is collected, produces 4,042,402 tons of CO2 equivalent per year and costs 143, 296, 983.4 yearly. In scenario 7, considered the most optimized management model for Kinshasa in this study, municipal solid waste is valorized through different treatment processes and atmospheric pollution reaches 2,835,491 tons of CO2 equivalent yearly, with a management cost of 152, 790, 779.4 USD/year. This study finds that the optimization of the Municipal Solid Waste management system in Kinshasa city causes the atmospheric pollution in terms of CO2 equivalent to decrease by half, when all waste is collected. Landfill diversion rate reaches up to 70%, but the overall MSW management cost increases by almost eight times as much as the current operational cost. The optimization of the management system is done by increasing waste collection coverage and implementing diverse streams of waste valorization. Despite the wide use of the Life Cycle Assessment method in waste management and decision making, this method has not yet been, to the best knowledge of the authors, applied in estimating Greenhouse gas emissions and cost of the Municipal Solid Waste in the specific context of Kinshasa city.

Guangdong's embodied carbon emission in China's inter-provincial trade based on MRIO model.

This paper constructs an embodied carbon model in inter-provincial trade based on China's inter-provincial multi-regional input-output table. By analyzing the embodied carbon emissions for Guangdong with the forefront of economic development, this research reveals the impact of trade scale and structure between Guangdong Province and other provinces on embodied carbon emissions, and finds out key provinces and sectors for emission reduction. It can enable national and regional economic and environmental policies to be implemented into specific industries, guide capital flow to key sectors for emission reduction, provide comments for relevant national and provincial decision-making sectors to adjust trade structure, and play the role of inter-provincial trade in energy conservation and emission reduction.

Comparative study of linkage between environmental policy instruments and technological innovation: Case study on end-of-life vehicles technologies in Japan and EU.

A growing population and urbanization is a challenge for finite natural resources. Without strict regulation to recycle, recover and reuse resources, waste is discarded with no value. Every year throughout the world, more than twenty-five million vehicles turn into end-of-life vehicles (ELV) and most of their valuable resources end up in landfill sites. This research analyses the effect of regulation on ELV innovation for additional recovery of resources in Japan and EU nations using patent data as a proxy. The analysis determines the statistical difference in patent activity before and after regulations were enacted in the case studies. The relevant data on ELV technologies was gathered for the period 1985-2013. The study suggests that in general environmental regulation in Japan drove innovation and reveals that environmental policy in Japan was more effective in enabling innovation compared to EU nations. Specifically, the results from these developed countries can be used by the rapidly growing developing countries in automobile manufacturing like China for amendment of their ELV regulation accordingly.