- Eden Shankar
WHAT IS THE RELATIONSHIP BETWEEN WASTE MANAGEMENT AND THE CLIMATE?
TAICT believes that good solid waste management practices are the first step to mitigating the climate crisis. The relationship between waste management and climate change may appear apparent on the surface. However, how much do most people really know about why effective waste management is key to reducing emissions and, therefore an essential component in securing a sustainable future? Greenhouse gases (GHGs) are emitted through a number of human activities, including the decomposition of organic waste on landfill sites. When waste decomposes, it produces methane, which is a powerful GHG. In fact, methane has a global warming potential 28 times greater than carbon dioxide (CO2) over a 100-year period! Therefore, by managing our waste effectively and reducing our reliance on landfills, we can make a significant dent in our GHG emissions. In this article, we will discuss the extent to which effective waste management practice aids in climate change mitigation and, conversely, consider the environmental impact of poor waste management practices.
Waste Generation in India
The average amount of waste generated by households in India varies in rural and urban areas and across cities with different population densities. As of 2021, India has been producing about 62 million tonnes of Municipal Solid Waste (MSW) annually. This can be broken down into 160,038.9 tonnes per day This includes organic waste as well as recyclable materials. The Central Pollution Control Board (CPCB) estimates that there is a collection efficiency of 95.4%, of which 50% is treated and 18.4% is landfilled. The remaining 31.7% is unaccounted for and, therefore presumably dumped illegally. However, the accuracy of these figures is questionable. The methods of collection for this report are not verifiable. Further, this high figure of collection efficiency seems unlikely when the reality on the ground is that 2,636 wards do not have a facility for door collection. Moreover, most slum dwellings, which account for a significant proportion of the country's population, have no waste management infrastructure or provisions at all.
Landfill at Bhalswa, New Delhi.
There are several reasons that a large proportion of waste in India goes either uncollected or unprocessed. Arguably, these reasons qualify for a discussion of a more political nature that unpacks India’s complicated relationship with bureaucracy, corruption and legislature. Additionally, the reasons for waste being left unsegregated are also complex in nature. The problem is not limited to citizens failing to practise segregation at source, but extends itself over to municipal corporations who collect waste and mix it all together even when it is segregated. It is more profitable for municipal corporations to collect mixed waste, as it results in higher fees for landfilling. Segregated waste can be recycled or composted, which is undertaken by external vendors and agencies, and therefore offers a lower profit margin. The reasons for the low rate of segregation go on; however, for the sake of this article, we will highlight the issue of why unsegregated waste is so difficult to process and further the impact of unprocessed and landfilled waste on the climate.
Solid Waste as a source of emissions
The solid waste generated by households can generally be categorised into wet, dry and hazardous waste. When segregated, the potential for productively utilising waste may as well be limitless. Wet waste can be composted or used to generate energy through bio-methanation. Recycling allows for dry waste to pass through supply chains many times over with a limited environmental impact, i.e. not creating further waste. Finally, hazardous waste that must be incinerated can also be utilised in waste-to-energy processes to create steam for the production of electricity.
However, when unsegregated, these forms of waste can have detrimental effects on public health and the environment. Waste that is not segregated at source is almost entirely impossible to segregate after collection, resulting in dumping or landfilling.
Landfills are one of the largest sources of human-generated methane emissions. When MSW is dumped in a landfill, it begins a process of decomposition that occurs in four phases. The first phase is aerobic, taking place when organic particles in the waste come into contact with oxygen. Following this, anaerobic (without oxygen) conditions are established, where microbes that aid in the decomposition of the waste begins to release methane. The biological decomposition of waste produces what is known as landfill gas, which comprises methane, carbon dioxide and other chemicals at low concentrations, such as ammonia, sulphide and other volatile organic compounds.
Landfills also produce leachate, a liquid percolating through the waste that contains high concentrations of organic carbon, nitrogen, chloride, iron, manganese and phenols, all of which vary depending on the composition of the waste, precipitation, the age of the waste and other factors. Leachate has very harmful effects on groundwater and, therefore on human and animal health. The heavy metals in the leachate are also retained by the soil, and uptake by plants, therefore entering the food chain, affecting crop growth and introducing disease to animals and humans consuming them. An effective system for the collection and removal of leachate is, therefore a prerequisite for all landfill sites.
Methane is the main GHG that causes the formation of ground-level ozone, which is a hazardous air pollutant that has effects on human and animal health and reduces crop yields. When leaving the atmosphere, methane undergoes a process of oxidisation, resulting in the formation of water vapour and carbon dioxide, which is another greenhouse gas that has significant warming effects. In this same process of oxidisation, methane reacts with hydroxyl radicals (OH), which normally serve to clean pollutants from the air. However, this reaction reduces the amount of OH available to remove other kinds of air pollutants. Reducing the amount of methane released into the air through human activity will have a significant impact on climate change, as it takes only about a decade for it to break down, as opposed to carbon dioxide, which takes several centuries. This means reducing methane emissions will help keep the world on track to 1.5°C warming compared to pre-industrial levels. Presently, MSW generated by households is the third largest anthropogenic source of methane, forming 11% of all methane emissions. This means that the effective processing of waste will have a direct impact on methane emissions and thus, on global warming.
The Bottom Line
Waste that is properly processed is less harmful to people and the planet and does not require a place, such as a landfill, to be stored. If all MSW generated by humanity, that is 2.01 billion tonnes a year*, were to remain unprocessed and need to be landfilled, the amount of space required, emissions caused and ultimately increase in global temperature would increase unfathomably. Waste management has a direct relationship with the climate crisis, as illustrated above. Therefore it is crucial that we not only begin to practice waste segregation at a household level but also hold municipal institutions accountable for their failure to manage waste adequately. Dumping waste that could be processed is a violation of our right to a decent and healthy quality of life, and it has severe implications on the lives and health of current and future generations, especially those belonging to lower socio-economic backgrounds. This issue deserves to be treated in a manner that reflects this severity. You can read more about our public interest litigation that is doing this here.
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