Not only carbon dioxide but also soot released from fires has impact on global warming, study finds
The focus on plastics in our oceans has highlighted the global problem of waste disposal. Household bin collection and the recycling, composting, burying or incinerating of our rubbish are key functions of a modern city. But in low-income countries about 90% of waste ends up in open dumps or is burned in the open air.
Obviously, burning waste creates carbon dioxide and the smoke contains health-harmful particles, but it also contains tiny black particles of soot which have a huge short-term climate impact. Researchers from London’s King’s and Imperial colleges burned small samples of rubbish and measured the smoke. Soot amounts were greatest when the rubbish contained two plastics: polystyrene and polyethylene terephthalate (more commonly abbreviated to PET and often used to make drinks bottles). Burning waste containing textiles, many of these being plastic, also contributed to high soot releases.
Using data on the contents of rubbish from around the world, the researchers estimated that the soot from open waste burning had a global warming impact equivalent to between 2% and 10% of the global emissions of carbon dioxide. Unless addressed, this problem is set to worsen as the amount that we throw away is expected to increase by 70% by 2050.