Waste Management

Summary——————–Overview——————–Solutions

Sustainable waste management is simple in the natural world. Thanks to the carbon, water, and other cycles, organic waste is never really wasted. It’s just repurposed to the benefit of the ecosystem. Although there are many more challenges associated with sustainable waste management in the human world, the objective is the same. Waste must be handled to the benefit of society.

Effective waste management strategies are essential to recover materials and reduce impacts. In this section, we’ll see how countries can improve their waste management systems to mitigate climate change and biodiversity loss.

Types of Waste

Municipal Solid Waste

Municipal solid waste [MSW] can be defined in a number of ways. Here, we’ll define MSW as residential, commercial, and institutional waste. It’s the category of waste that individuals typically think of when discussing waste management. In 2016, 2.01 billion tonnes [20.1 billion pandas] of MSW were generated. This yearly waste output is projected to increase by 69% by 2050.

In 2016, these 2.01 billion tonnes of MSW emitted 1.6 billion tonnes of CO2e, which represents 35% of global GHG emissions the same year. If waste management systems remain unchanged, MSW emissions are projected to increase by 63% by 2050.

Developed countries generate the most MSW per capita, with North America leading the way at 2.21 kg of waste per person per day. For reference, the global average is 0.74 kg/capita/day.

Other Types of Waste

Waste doesn’t need to be municipal or solid. In fact, MSW represents only a fraction of the global waste output. Industry and agriculture respectively generated 17 and 4.5 times more waste than MSW in 2016.

Comparing special waste generation to MSW’s global average of 0.74 kg/capita/day, it’s clear that improving waste management at the larger scales is a priority. Especially in high-income countries that generate the bulk of industrial waste.

Municipal Waste Management Systems

Municipal waste management systems may not deal with numerous types of special waste, but many of them employ good practices that can be used for special waste management. Industries and other large waste producers can incorporate these practices to reduce their impacts.

As such, the remainder of this section will focus on MSW to determine which practices can lead to sustainable special waste management.

MSW Composition

MSW is a broad category of waste that includes recyclables, organic matter, and non-recoverable waste. Globally, MSW is dominated by organic waste, which makes sense considering that roughly a third of all food produced for human consumption is wasted or lost.

Waste Collection

The first step in a waste management system is waste collection. Unfortunately, the cheapest option is to not collect waste at all, which explains why many developing countries continue to experience low waste collection rates. Uncollected waste can emit significant amounts of GHGs and contribute to biodiversity loss, as it’s usually open dumped or burned.

When waste does get collected, countries can decide which waste management practices to employ. Once again, open dumping and burning are the cheapest options, so many low-income countries adopt these polluting practices at a large scale.

High-income countries that are fortunate enough to be able to manage waste sustainably often choose to do so. By separating the different types of MSW and employing effective waste management practices, high-income countries can minimize their waste-related impacts.

Non-recoverable Waste

Once waste is collected, it can be sorted as recyclable, compostable, or non-recoverable waste. In developed countries, layers of non-recoverable waste are usually deposited in landfills, which are essentially craters in the Earth waiting to be filled with waste. These layers are then compacted very tightly to ensure that landfills last as long as possible.

A well-designed landfill has many pollution control measures in place to make sure that pollutants don’t contaminate the surrounding soil. It also aims to control methane emissions that arise from organic waste decomposition in the absence of air.

Despite these pollution control processes, landfilling is widely regarded as a last resort practice in developed countries, assuming that open dumping and burning aren’t acceptable alternatives.

Instead, countries are looking at waste management practices that offer benefits, even for non-recoverable waste. One such practice is incineration, where waste is burned in a controlled facility to recover energy. The amount of GHGs emitted from this combustion process varies depending on the pollution control technologies adopted, while the ash output is usually landfilled.

For smaller countries, incineration is a good way to reduce waste volumes that enter landfills, which can extend landfill lifetimes and avoid having to dig new ones.

Recyclables

Recycling is another alternative practice to landfilling that provides multiple benefits. Similar to incineration, recycling can reduce the amount of waste headed toward landfills, which extends their lifetime. However, contrary to incineration, recycling doesn’t recover energy from waste. It instead recovers materials that have already gone through energy/pollution-intensive manufacturing. This way, new products made with recycled materials don’t need to deplete more resources or consume more energy [even though recycling does require energy].

In an ideal circular economy, recycling would be efficient enough to avoid waste, decrease resource extraction, and reduce energy consumption across all sectors. Unfortunately, as seen in an earlier section, recycling faces plenty of obstacles that keep this ideal circular economy out of reach, for now. The following graph shows how much plastic waste management systems have to improve to reach a circular economy.

Organic Waste

Organic waste can also be diverted from landfills. On top of extending landfill lifetimes, separating organic waste is essential to reduce GHG emissions, since organic matter can produce methane as it decomposes in landfills. As a reminder, methane is 28 times more greenhousy than CO2.

Diverting organic waste is also important to recover the nutrients present in food scraps, yard trimmings, and other organics. These recovered nutrients can then be used to make natural compost and fertilizer, which reduces the need for synthetic products. In turn, that often results in less GHG emissions and pollution.

Composting is one of the few waste management practices that can effectively recover nutrients. Composting’s main benefit when compared to other strategies is that it’s simple. Since decaying organic matter only produces CO2 when in contact with air, there’s no need to worry about potent methane emissions. Additionally, composting sequesters some of the organic waste’s carbon content directly into the compost product, along with valuable nutrients. So composting can have negative emissions due to captured biogenic emissions and avoided use of synthetic fertilizers.

Another way to recover value from organic waste is through biogas or renewable natural gas production. As discussed in an earlier section, organic waste can be anaerobically digested to produce these gases, which can then be combusted to produce energy. The gasification process also outputs digestate, which is essentially concentrated organic waste. This nutrient-rich by-product can be used to make fertilizer.

Reducing Waste Impacts

The 3 Rs

The most effective way to lower waste impacts is to reduce waste generation, and the easiest way to do that is to reduce production. “Reducing by design” is one option that companies have to reduce their waste impacts, without compromising the business side of things. Governments can incentivize companies to reduce by design with “extended producer responsibility” policies, using the green dot program for example. Alas, reducing production completely is impossible.

As such, waste management systems also need to adopt better practices to reduce waste impacts. Special focus should be placed on industrial, agricultural, and other non-MSW types of waste that dominate global waste production. Governments can improve policies to incentivize companies to reduce their waste and manage it with good practices.

Waste Exports

Governments can also review policies surrounding international waste exports. With large gaps in waste management quality between high-income and low-income countries, it’s essential to take advantage of good practices when available.

Currently, waste generated by companies in developed countries can easily end up polluting low-income countries, due to weak international policies on waste exports. Making it harder for companies to export their waste can reduce impacts worldwide.

E-Waste

Impacts

Waste management systems are always adapting to the new types of waste generated by companies. Unfortunately, innovation can occasionally outpace waste management advances. When that happens, global waste crises can arise, resulting in significant GHG emissions and toxic pollution.

The global e-waste [electronic/electrical waste] crisis is a prime example. Though e-waste accounts for a relatively small share of global waste generation, it can have severe environmental impacts when managed poorly.

Notably, when e-waste is open dumped, heavy metals can leach and pollute surrounding air, water, and soil for decades. When e-waste is burned – either to recover valuable metals or reduce waste volumes – GHGs are released into the atmosphere.

Value

Good e-waste management practices can recover valuable materials and reduce impacts. The average tonne of e-waste contains 100 times more gold than a tonne of gold ore. Considering that 50 million tonnes were generated in 2018, e-waste’s estimated value of $62.5 billion USD seems reasonable. By 2050, annual e-waste generation is projected to reach 120 million tonnes.

Unfortunately, only 20% of e-waste was recycled formally in 2018. Governments can develop policies to improve this recycling rate, to increase material recovery and reduce environmental impacts. For reference, it’s estimated that recycling metals is 2-10 times less energy consuming than smelting new metals from mineral ores. More specifically, mining gold from e-waste can emit 80% less CO2 than ‘normal mining’.