Alternative MSW treatment options to reduce global greenhouse gases emissions - the Israeli example

The increased concern about environmental problems caused by inadequate waste management, as well as the concern about global warming, promotes actions toward a sustainable management of the organic fraction of the waste. Landfills, the most common means to dispose of municipal solid waste (MSW), lead to the conversion of the organic waste to biogas, containing about 50% methane, a very active greenhouse gas (GHG). One unit of methane has a global warming potential of 21 computed for a 100-year horizon or 56 computed for 20 years. The waste sector in Israel contributes 13% of total greenhouse gases (GHG) emissions for a time horizon of 100 years (for a time horizon of 20 years, the waste sector contribution equals to more than 25% of total GHG emissions). The ultimate goal is to minimize the amount of methane (CH4) by converting it to CO2. This can be achieved by physicochemical means (e.g., landfill gas flare, incineration) or by biological processes (e.g., composting, anaerobic digestion). Since the waste in Israel has a high organic material content, it was found that the most cost-effective means to treat the degradable organic components is by aerobic composting (investment of less than US$ 10 to reduce emission of one ton CO2 equivalent per year). Another benefit of this technology is the ability to implement it within a short period. The suggested approach, which should be implemented especially in developing countries, could reduce a significant amount of GHG at relatively low cost and short time. The development of a national policy for proper waste treatment can be a significant means to abate GHG emissions in the short term, enabling a gain in time to develop other means for the long run. In addition, the use of CO2 quotas will credit the waste sector and will promote profitable proper waste management.

Greenhouse gas (GHG) emissions from post-consumer waste and wastewater are a small contributor (about 3%) to total global anthropogenic GHG emissions. Emissions for 2004-2005 totalled 1.4 Gt CO2-eq year(-1) relative to total emissions from all sectors of 49 Gt CO2-eq year(-1) [including carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and F-gases normalized according to their 100-year global warming potentials (GWP)]. The CH4 from landfills and wastewater collectively accounted for about 90% of waste sector emissions, or about 18% of global anthropogenic methane emissions (which were about 14% of the global total in 2004). Wastewater N2O and CO2 from the incineration of waste containing fossil carbon (plastics; synthetic textiles) are minor sources. Due to the wide range of mature technologies that can mitigate GHG emissions from waste and provide public health, environmental protection, and sustainable development co-benefits, existing waste management practices can provide effective mitigation of GHG emissions from this sector. Current mitigation technologies include landfill gas recovery, improved landfill practices, and engineered wastewater management. In addition, significant GHG generation is avoided through controlled composting, state-of-the-art incineration, and expanded sanitation coverage. Reduced waste generation and the exploitation of energy from waste (landfill gas, incineration, anaerobic digester biogas) produce an indirect reduction of GHG emissions through the conservation of raw materials, improved energy and resource efficiency, and fossil fuel avoidance. Flexible strategies and financial incentives can expand waste management options to achieve GHG mitigation goals; local technology decisions are influenced by a variety of factors such as waste quantity and characteristics, cost and financing issues, infrastructure requirements including available land area, collection and transport considerations, and regulatory constraints. Existing studies on mitigation potentials and costs for the waste sector tend to focus on landfill CH4 as the baseline. The commercial recovery of landfill CH4 as a source of renewable energy has been practised at full scale since 1975 and currently exceeds 105 Mt CO2-eq year(-1). Although landfill CH4 emissions from developed countries have been largely stabilized, emissions from developing countries are increasing as more controlled (anaerobic) landfilling practices are implemented; these emissions could be reduced by accelerating the introduction of engineered gas recovery, increasing rates of waste minimization and recycling, and implementing alternative waste management strategies provided they are affordable, effective, and sustainable. Aided by Kyoto mechanisms such as the Clean Development Mechanism (CDM) and Joint Implementation (JI), the total global economic mitigation potential for reducing waste sector emissions in 2030 is estimated to be > 1000 Mt CO2-eq (or 70% of estimated emissions) at costs below 100 US$ t(-1) CO2-eq year(-1). An estimated 20-30% of projected emissions for 2030 can be reduced at negative cost and 30-50% at costs < 20 US$ t(-) CO2-eq year(-1). As landfills produce CH4 for several decades, incineration and composting are complementary mitigation measures to landfill gas recovery in the short- to medium-term--at the present time, there are > 130 Mt waste year(-1) incinerated at more than 600 plants. Current uncertainties with respect to emissions and mitigation potentials could be reduced by more consistent national definitions, coordinated international data collection, standardized data analysis, field validation of models, and consistent application of life-cycle assessment tools inclusive of fossil fuel offsets.

The role of global waste management and circular economy towards carbon neutrality

In December 2007 the United Nations Framework Convention on Climate Change (UNFCCC) took place in Bali. It was based on the IPCC report no. 4 presented in Barcelona on November 2007. The messages are briefly: • Warming of the climate system is unequivocal; • Global greenhouse gas (GHG) emissions due to human activities have grown since pre-industrial times; • Continued GHG emissions at or above current rates would cause further warming and induce many changes in the global climate system during the 21st century that would very likely be larger than those observed during the 20th century; • Key mitigation technologies in the waste sector: Landfill Gas (LFG) methane recovery; waste incineration with energy recovery; composting of organic waste; controlled waste water treatment; recycling and waste minimisation; biocovers and biofilters to optimise methane oxidation. The above by the IPCC proposed mitigation technologies for the waste sector can be categorized regarding specific waste treatment scenarios and their efficiency expressed in kg CO2 equivalent emitted per ton of waste. • Landfill w/o LFG recovery 1850 kg CO2-eq; • Landfill with LFG recovery 250–775 kg CO2-eq; • Energy-from-Waste plant −1000..−100 kg CO2-eq. With a population of little over 300 million people and a per capita municipal waste generation rate of 760 kg/person.year, the total waste generated in the USA is about 230 million Mg/year (OECD). With the treatment scenarios discussed above, the following can be stated: • If all wastes were landfilled waste disposal would correspond to 425 million tons of CO2 equivalents. • If all wastes were incinerated in Energy-from-Waste (EfW) plants, the emissions could be reduced by about 500 million tons of CO2 equivalents (about 9% of today’s US CO2 output) and make the waste management sector a GHG emissions sink. • The total electricity generated from EfW plants could be as high as 15,000 MW replacing about 50 standard 300 MW power plant units. To an average US 4 person household about 3 t/year of municipal solid wastes can be allocated, corresponding to an annual difference between landfilling without LFG recovery and EfW treatment of about 6.9 Mg CO2-eq /year. If this household wanted to achieve the same reduction of CO2 equivalent emissions by other means than having these wastes burnt in a modern EfW plant, they have the following options: • Remove one automobile from use (EPA: 6.0 Mg CO2-eq /year); • Cut household electricity consumption by 80% (EIA: 7.8 Mg CO2-eq /year). The European parliament commission has proposed to reduce CO2 emissions in Europe to 20–30% below 1990 levels. In comparison with Europe, annual GHG emissions (CO2-eq/person year) in the U.S. today are on a level about double that of the Europe. In order to achieve a similar reduction in the U.S., significant efforts have to be done on all energy fronts. Energy-from-Waste (EfW) is one of them, which at the same time solves a space and pollution problem and does not leave these issues to future generations.

In the 21st century, global warming and climate change are among the greatest environmental challenges and humanitarian crisis. Globally, annual greenhouse gas (GHGs) emissions from solid waste disposal sites is estimated to be approximately a quarter of total anthropogenic methane emission. Integrated solid waste management, therefore, provides significant opportunities to control environmental pollution and minimize the negative impacts of global climate change. This chapter illustrates the current status of global GHGs emission in relationship with population growth and solid waste generation. Mathematic models used to quantify GHGs generated from the waste sector as the zero-order model (i.e., SWANA, German EPER and IPCC Default Method) and the first-order model (i.e., TNO, LandGEM, IPCC First-Order Decay; FOD) are explained including application to certain inventory in selected countries. Life Cycle Assessment (LCA), which involves the cradle-to-grave concept, environmental burden from global warming and selected case studies are described and applied to assess GHGs emissions from various solid waste management options such as recycling, composting, sanitary landfilling, anaerobic digestion, incineration, mechanical biological treatment (MBT), source reduction, and utilization and application of biochar. Existing solid waste management practices and innovative options to achieve GHGs mitigation and community adaptation including resiliency are presented. Lessons learned and best practices in solid waste management from Thailand (i.e., Bangkok Kamphaeng Sean West: Landfill Gas to Electricity Project) and from other countries (i.e., GHGs mitigation project: MBT plant in Gaobeidian, Hebei province, People’s Republic of China; municipal solid waste composting project in Ikorodu, Lagos State, Federal Republic of Nigeria; and gasification, landfill gas and anaerobic digestion in Bali, Indonesia) are further discussed.

Achieving the Paris Agreement 1.5 C target requires a reversal of the growing atmospheric concentrations of methane, which is about 80 times more potent than CO 2 on a 20-year timescale. The Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report stated that methane is underregulated, but little is known about the effectiveness of existing methane policies. In this review, we systematically examine existing methane policies across the energy, waste, and agriculture sectors. We find that currently only about 13% of methane emissions are covered by methane mitigation policies. Moreover, the effectiveness of these policies is far from clear, mainly because methane emissions are largely calculated using potentially unrepresentative estimates instead of direct measurements. Coverage and stringency are two major blind spots in global methane policies. These findings suggest that significant and underexplored mitigation opportunities exist, but unlocking them requires policymakers to identify a consistent approach for accurate quantification of methane emission sources alongside greater policy stringency. ll

Advanced wastewater treatment processes and novel technologies are adopted to improve nutrient removal from wastewater so as to meet stringent discharge standards. Municipal wastewater treatment plants are one of the major contributors to the increase in the global greenhouse gas (GHG) emissions and therefore it is necessary to carry out intensive studies on quantification, assessment and characterization of GHG emissions in wastewater treatment plants, on the life cycle assessment from GHG emission prospective, and on the GHG mitigation strategies. Greenhouse Gas Emission and Mitigation in Municipal Wastewater Treatment Plants summarises the recent development in studies of greenhouse gases’ (CH4 and N2O) generation and emission in municipal wastewater treatment plants. It introduces the concepts of direct emission and indirect emission, and the mechanisms of GHG generations in wastewater treatment plants’ processing units. The book explicitly describes the techniques used to quantify direct GHG emissions in wastewater treatment plants and the protocol used by the Intergovernmental Panel on Climate Change (IPCC) to estimate GHG emission due to wastewater treatment in the national GHG inventory. Finally, the book explains the life cycle assessment (LCA) methodology on GHG emissions in consideration of the energy and chemical usage in municipal wastewater treatment plants. In addition, the strategies to mitigate GHG emissions are discussed. The book provides an overview for researchers, students, water professionals and policy makers on GHG emission and mitigation in municipal wastewater treatment plants and industrial wastewater treatment processes. It is a valuable resource for undergraduate and postgraduate students in the water, climate, and energy areas; for researchers in the relevant areas; and for professional reference by water professionals, government policy makers, and research institutes. ISBN: 9781780406305 (Print) ISBN: 9781780406312 (eBook) ISBN: 9781780409054 (ePUB)

Cutting through the noise on negative emissions

Abstract. To track progress towards keeping global warming well below 2 ∘C or even 1.5 ∘C, as agreed in the Paris Agreement, comprehensive up-to-date and reliable information on anthropogenic emissions and removals of greenhouse gas (GHG) emissions is required. Here we compile a new synthetic dataset on anthropogenic GHG emissions for 1970–2018 with a fast-track extension to 2019. Our dataset is global in coverage and includes CO2 emissions, CH4 emissions, N2O emissions, as well as those from fluorinated gases (F-gases: HFCs, PFCs, SF6, NF3) and provides country and sector details. We build this dataset from the version 6 release of the Emissions Database for Global Atmospheric Research (EDGAR v6) and three bookkeeping models for CO2 emissions from land use, land-use change, and forestry (LULUCF). We assess the uncertainties of global greenhouse gases at the 90 % confidence interval (5th–95th percentile range) by combining statistical analysis and comparisons of global emissions inventories and top-down atmospheric measurements with an expert judgement informed by the relevant scientific literature. We identify important data gaps for F-gas emissions. The agreement between our bottom-up inventory estimates and top-down atmospheric-based emissions estimates is relatively close for some F-gas species (∼ 10 % or less), but estimates can differ by an order of magnitude or more for others. Our aggregated F-gas estimate is about 10 % lower than top-down estimates in recent years. However, emissions from excluded F-gas species such as chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs) are cumulatively larger than the sum of the reported species. Using global warming potential values with a 100-year time horizon from the Sixth Assessment Report by the Intergovernmental Panel on Climate Change (IPCC), global GHG emissions in 2018 amounted to 58 ± 6.1 GtCO2 eq. consisting of CO2 from fossil fuel combustion and industry (FFI) 38 ± 3.0 GtCO2, CO2-LULUCF 5.7 ± 4.0 GtCO2, CH4 10 ± 3.1 GtCO2 eq., N2O 2.6 ± 1.6 GtCO2 eq., and F-gases 1.3 ± 0.40 GtCO2 eq. Initial estimates suggest further growth of 1.3 GtCO2 eq. in GHG emissions to reach 59 ± 6.6 GtCO2 eq. by 2019. Our analysis of global trends in anthropogenic GHG emissions over the past 5 decades (1970–2018) highlights a pattern of varied but sustained emissions growth. There is high confidence that global anthropogenic GHG emissions have increased every decade, and emissions growth has been persistent across the different (groups of) gases. There is also high confidence that global anthropogenic GHG emissions levels were higher in 2009–2018 than in any previous decade and that GHG emissions levels grew throughout the most recent decade. While the average annual GHG emissions growth rate slowed between 2009 and 2018 (1.2 % yr−1) compared to 2000–2009 (2.4 % yr−1), the absolute increase in average annual GHG emissions by decade was never larger than between 2000–2009 and 2009–2018. Our analysis further reveals that there are no global sectors that show sustained reductions in GHG emissions. There are a number of countries that have reduced GHG emissions over the past decade, but these reductions are comparatively modest and outgrown by much larger emissions growth in some developing countries such as China, India, and Indonesia. There is a need to further develop independent, robust, and timely emissions estimates across all gases. As such, tracking progress in climate policy requires substantial investments in independent GHG emissions accounting and monitoring as well as in national and international statistical infrastructures. The data associated with this article (Minx et al., 2021) can be found at https://doi.org/10.5281/zenodo.5566761.

Greenhouse gas emissions from different municipal solid waste management scenarios in China: Based on carbon and energy flow analysis

The waste sector is a significant source of greenhouse gas(GHG) emissions and clarifying its emission trends and characteristics is the premise for formulating GHG emission reduction strategies. Using the IPCC inventory model, the GHG emissions from the municipal solid waste(MSW) sector in China during 2010 to 2020 were estimated. The results showed that GHG emissions increased from 42.5 Mt in 2010 to 75.3 Mt in 2019, then decreased to 72.1 Mt in 2020. MSW landfills were the main source of GHG emissions. Further, with the increase in the proportion of waste incineration, the proportion of GHG incineration increased rapidly from 16.5% in 2010 to 60.1% in 2020. In terms of regional distribution, East and South China were the regions with the highest emissions, and Guangdong, Shandong, Jiangsu, and Zhejiang were the provinces with the largest GHG emissions. Implementing MSW classification, changing the MSW disposal modes from landfilling to incineration, improving the LFG collection efficiency of landfills, and using biological functional materials as the cover soil to strengthen the methane oxidation efficiency are the main measures to achieve GHG emission reduction in waste sectors.

Greenhouse gas emission inventories from waste sector in China during 1949–2013 and its mitigation potential

China is one of the largest contributors to global greenhouse gas (GHG) emissions, and the livestock sector is a major source of non-CO2 GHG emissions. Mitigation of GHG emissions from the livestock sector is beneficial to the sustainable development of the livestock sector in China. This study investigated the provincial level of GHG emissions from the livestock sector between 2000 and 2020 in China, to determine the driving factors affecting the provincial-level GHG emissions from the livestock sector, based on the logarithmic mean Divisia index (LMDI) model, which took into account of technological progress, livestock structure, economic factor, and agricultural population. Moreover, a gray model GM (1, 1) was used to predict livestock GHG emissions in each province until 2030 in China. The results showed that the GHG of Chinese livestock sector was decreased from 195.1 million tons (MT) CO2e in 2000 to 157.2 MT CO2e in 2020. Henan, Shandong, and Hebei provinces were the main contributors to the reduction in Chinese livestock GHG emissions, with their livestock GHG emissions reduced by 60.1%, 53.5% and 45.5%, respectively, in 2020 as compared to 2000. The reduction in GHG emissions from the Chinese livestock sector can be attributed to two main factors: technological progress and the shrinking of the agricultural laborers. In contrast, the agricultural economic development model with high input and high emissions showed a negative impact on GHG emission reduction in China’s livestock sector. Furthermore, the different livestock structure in each province led to different GHG reduction effects on the livestock sector. Under the gray model GM (1,1), the GHG emissions of the livestock sector will be reduced by 33.7% in 2030 as compared with 2020 in China, and the efficiency factor will account for 76.6% of the positive effect of GHG reduction in 2030. The eastern coastal region will be the main contributor to the reduction of GHG emissions from the Chinese livestock sector in 2030. Moreover, recommendations (such as upgrading livestock management methods and promoting carbon emission mitigation industries) should be proposed for the environmentally sustainable development of the livestock sector in the future.

Accuracy in national greenhouse gas (GHG) emissions estimation is a key element for outlining best strategies to reduce GHG emissions from various source sectors of the economy. In this study, an initial attempt has been made to estimate GHG emissions from waste sector in Rawal Town - an urban city of Rawalpindi district in Pakistan. Tier 1 approach of Revised 1996 Intergovernmental Panel on Climate Change (IPCC) Guidelines and the best available primary activity data collected for the study area were applied for the fiscal year June 2014-May 2015. Emissions of three GHGs - carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) under three waste management practices i.e. solid waste disposal sites, wastewater handling, and waste incineration were assessed. Out of the total 417.84 Gg CO2 equivalent emissions, the share of each gas (CH4, CO2 and N2O) in total emissions was found as 11.31, 0.53, and 0.58 Gg respectively. Solid waste disposal sites are identified as the largest source of CH4 emissions (10.73 Gg). To make the country's GHG emissions estimates more robust for waste sector, such type of local area based studies established on primary activity data could be advantageous for reducing uncertainties in national emission estimates.

Asian countries have been concentrating on providing sustainable economic growth since they have had to face the severe consequences of climate change. Thus, this study aims to fill a research gap by investigating whether waste sector emissions significantly contribute to greenhouse gas (GHG) emissions. In general, this study proposes three research hypotheses derived from a review of the literature on GHG emissions. The first and second hypotheses examine whether waste sector emissions, economic growth and other indicators significantly contributed to the total GHG emissions in 13 Asian countries between 2000 and 2016. The third hypothesis investigates whether countries individually and significantly determine waste sector emissions. Using pooled ordinary least squares and least squares dummy variable (LSDV) estimations, the study shows that that the emissions from the waste, agriculture, manufacturing, and construction sectors, as well as from land use and change, were positively associated with total GHG emissions. Second, economic growth and urban and rural population growth show the possibility of reducing GHGs in Asian countries. Subsequently, the LSDV estimation identified that India and Indonesia emitted 72 million tonnes and 148 million tonnes of carbon dioxide equivalent between 2000 and 2016 from the waste sector.