New Megacities are outgrowing their trash systems, and MSW-to-energy could close the gap.

Jakarta collects about a quarter of the trash its residents generate. Karachi manages a third. Sao Paulo, one of the wealthier megacities in the developing world, still only picks up 36 percent. The rest sits in open dumps, gets burned in the street, or washes into rivers and eventually the ocean. These aren't outlier cities. They're a preview of what happens when municipal solid waste (MSW) generation outpaces the infrastructure built to handle it, a gap that's opening up in more places every year.

The scale is hard to grasp from a single household bin. The World Bank estimated the world generated 2.24 billion tonnes of solid waste in 2020. By 2022 that figure had already climbed to 2.56 billion tonnes, a level the World Bank's own 2018 projections hadn't expected to hit until 2030. At current trends, annual waste generation reaches nearly 3.88 billion tonnes by 2050, a 75 percent jump from 2020 levels. Urbanization is the main driver: cities produce more waste per person than rural areas, and the world keeps adding city dwellers faster than it adds landfill capacity or collection trucks.

Why megacities hit the wall first

A megacity, defined as an urban area with more than 10 million people, concentrates every part of the waste problem into one place. Collection routes get longer and more expensive to run. Land for new landfills gets scarcer and more contested, since nobody wants a dump next door and cities have already used up their cheap, accessible sites. Informal settlements often sit outside any formal collection route at all, so waste piles up where the city's infrastructure was never built to reach.

The result is a two-tier system. Wealthier neighborhoods get regular pickup. Everywhere else, residents burn trash for lack of a better option, dump it in waterways, or watch it collect in open piles that breed disease and leach into groundwater. The World Bank has flagged that billions of people worldwide still lack access to controlled waste disposal, and megacities in South Asia, Southeast Asia, and parts of Africa carry a disproportionate share of that gap. The American Society of Civil Engineers has raised similar flags closer to home, warning that U.S. solid waste infrastructure is aging faster than it's being replaced, even in a country with far more collection capacity than Jakarta or Karachi.

Turning the volume problem into a power source

The instinct in a lot of these cities has been to build more landfills or ship the problem somewhere else. Neither scales. Landfill space is finite and getting more expensive as cities grow outward into the land that used to hold it. Exporting waste has run into its own wall too, as countries that used to accept it have tightened or closed their borders to foreign trash.

Waste-to-energy conversion offers a different math. Instead of treating MSW purely as a disposal problem, it treats the waste stream as a fuel source. Modern conversion processes can extract usable energy from material that would otherwise sit in a landfill for decades releasing methane, a greenhouse gas more than 25 times as potent as carbon dioxide over a 100-year period. Done well, this cuts landfill volume, reduces methane emissions, and produces renewable power at the same time. It doesn't replace recycling or waste reduction, but it gives cities a third option for the material that's left over after those efforts, which for most megacities is still the majority of what gets thrown away.

The cities furthest along on this, from parts of Northern Europe to Singapore, have shown that waste-to-energy can run at a scale that actually moves the needle on a city's total waste volume, not just a demonstration project on the side. That's the model megacities in faster-growing regions need to look at now, before their landfill capacity runs out entirely.

Nexus Biofuel works on exactly this problem: converting municipal solid waste into clean, usable energy so cities aren't stuck choosing between overflowing landfills and burning what they can't collect. If you want to see how MSW-to-energy conversion could fit into your city's or company's waste strategy, get in touch with our team.

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MSW, waste-to-energy, municipal solid waste, renewable energy, megacities