IB Environmental systems and societies 7.3B Waste Disposal and Management Notes

The Waste Hierarchy: Prevent First, Dispose Last

1. Waste management follows a hierarchy: the best options stop waste being made, and the worst simply bury or burn it.
2. In order of preference: reduce, reuse, recycle, recover energy, and only then dispose in landfill.
3. This splits into two approaches: preventative strategies that stop waste at the source, and restorative strategies that clean up damage already done.
4. Prevention is more sustainable because cleaning up is costly, incomplete and only ever reactive.

Preventative Strategies: Stopping Waste at the Source

1. Reduce consumption
   1. Buying less and choosing durable, low-packaging goods cuts waste before it exists (minimalism, zero-waste living).
2. Design out waste
   1. Eco-design makes products recyclable, repairable or biodegradable from the start.
3. Producer responsibility
   1. Extended Producer Responsibility (EPR) makes manufacturers pay for their products' end-of-life, which pushes better design.
4. Education and awareness
   1. Campaigns shift behaviour, from cutting single-use plastic to composting at home.

Restorative Strategies: Cleaning Up After the Damage

1. Clean-up of pollution
   1. Removing waste already released, such as ocean-plastic collection or oil-spill skimming.
2. Ecosystem restoration
   1. Rebuilding damaged habitats through reforestation or wetland rehabilitation.
3. Pollutant removal
   1. Bioremediation uses plants or microbes to draw pollutants out of soil and water.

Disposal Methods: Weighing the Trade-Offs

Every disposal method trades cost, energy, pollution and land against each other, and none is perfect.

1. Landfill
   1. Bury waste in lined sites. Cheap and scalable, and modern sites can capture methane for energy.
   2. But leachate pollutes groundwater, methane drives warming, sites fill up, and they are often placed near poor communities.
2. Incineration
   1. Burn waste at high temperature. Cuts volume by up to 90% and destroys pathogens, useful for medical waste.
   2. But it releases CO₂ and dioxins if poorly controlled, is costly, and leaves toxic ash.
3. Waste-to-energy
   1. Incineration that captures the heat as electricity, cutting fossil-fuel use and landfill.
   2. But it still emits CO₂, needs heavy investment, and can discourage recycling by demanding a constant supply of waste.
4. Recycling
   1. Reprocess materials into new products, saving raw materials and energy and cutting landfill.
   2. But not everything is recyclable, sorting is costly, and many plastics downcycle into lower-quality material.
5. Composting
   1. Let organic waste decompose into fertiliser, cutting landfill methane and enriching soil.
   2. But it needs space and time, can smell or attract pests, and handles only organic waste.
6. Export
   1. Ship waste abroad for processing. Cheaper for the exporter, but shifts the pollution and health burden onto poorer countries (see 7.3A).

Making Disposal Sustainable: Tools That Change Behaviour

1. Economic tools
   1. Taxes on landfill and plastic bags discourage waste; deposit-refund schemes and tax breaks reward recycling.
2. Laws and bans
   1. Bans on single-use plastics and mandatory recycling set the rules, but without enforcement they are ignored.
3. Infrastructure and access
   1. Kerbside collection, composting bins and e-waste drop-offs make the sustainable choice the easy one.

The Circular Economy: Designing Waste Out of the System

1. A linear economy runs “take, make, dispose”; a circular economy keeps materials in use in a closed loop.
2. Design for longevity
   1. Durable, repairable, modular products, such as Fairphone's swappable parts, cut e-waste.
3. Reuse and repair
   1. Refurbishment and resale extend product life, from Patagonia's repair service to second-hand platforms.
4. Recycle and recover
   1. Recovering materials at end of life: H&M turns old clothes into new fibre, and Apple's Daisy robot strips iPhones for metals.
5. Regenerate
   1. Using renewable, biodegradable inputs so waste feeds back into nature rather than piling up.

From Ownership to Access

1. The circular economy also shifts thinking from owning products to accessing services through leasing, rental and sharing.
2. This challenges the traditional growth model built on selling ever more new goods.