India’s macroplastic pollution emissions highest, warns study

Emissions from plastic pollution are the highest in India, with the country contributing to nearly one-fifth of global plastic emissions, according to a recent study published in the journal Nature and highlighted by a Mongabay-India (MI) report.

As reported by MI, the study, conducted by researchers at the University of Leeds, has created the ‘first ever global inventory of macroplastic pollution’. It names ‘uncollected plastic waste’ and ‘uncontrolled burning’ as the biggest causes of plastic pollution emissions. India tops the list, producing nearly 9.3 million tonnes (Mt) of macroplastic waste emissions every year, followed by Nigeria (3.5 Mt), Indonesia (3.4 Mt), and China (2.8 Mt).

Titled ‘A local-to-global emissions inventory of macroplastic pollution’, the study’s abstract states that negotiations for a global treaty on plastic pollution will shape future policies on plastics production, use and waste management. Its parties will benefit from a high-resolution baseline of waste flows and plastic emission sources to enable identification of pollution hotspots and their causes. The study estimates global plastic waste emissions at 52.1[48.3–56.3]Mt per year, with approximately 57%wt. and 43%wt. open burned and unburned debris, respectively.

This study defines macroplastic (plastic particles >5 mm) emission as “material that has moved from the managed or mismanaged systems in which waste is subject to a form of control, however basic (contained state) to the unmanaged system or the environment (uncontained state) with no control.” It further classifies emissions in two categories: debris, which is physical particles bigger than 5 mm and open, uncontrolled burning.

According to the study’s methodology, as pointed out in the MI report, India has been overestimating its waste collection coverage and underestimating its official waste generation rate. The authors believe this to be the case because the official statistics do not include rural areas, open burning of uncollected waste or informally recycled waste.

The study had a pointed, single-format focus on macroplastic emissions. The authors say that while “plastic pollution exists in many forms (macroplastic debris, air pollution, GHG emissions, chemicals and microplastics), it is implausible to quantify all of these in a single piece of work.” The study excludes emissions from construction and demolition, industrial plastic waste and sewage treatment, textiles, electrical and electronic equipment waste, and waste material arising at sea.

The researchers employed four different global datasets including data from the World Bank and the United Nations, and two national databases in this study, to create a city-level solid waste management database with worldwide coverage. Using machine learning and probabilistic material flow analysis, they identified emission hotspots across 50,702 municipalities worldwide from five land-based plastic waste emission sources – uncollected waste; littering; collection system; uncontrolled disposal; and rejects from sorting (recycling system).

The researchers found that the difference of emissions in plastic waste between the Global North and Global South countries, is stark, as the MI report notes. While littering is a major problem in the former, uncollected waste and uncontrolled burning were huge issues in the latter. The study also indicates that uncollected waste accounts for 68% of all plastic waste emissions and 85% of all debris emissions in the Global South. The authors state that understanding the mechanisms of plastic emission and gaining insights into the nature, scale, and causes of plastic pollution will support the creation of evidence-based action plans at national and sub-national levels to eliminate plastic from our environment. They strongly recommend the use of their research to mobilise the necessary resources from the Global North (those involved in the production and retail of plastics at all levels).

The study warns that plastic pollution is a global challenge requiring immediate action owing its environmental persistence and negative impact on ecosystems, infrastructure, society and the economy. The importance of this burgeoning issue has recently been recognized by the ratification of a United Nations draft resolution to create an internationally legally binding instrument to end plastic pollution, hereafter the ‘Plastics Treaty’. A global plastic pollution emissions inventory has been suggested as being critical to the success of the Plastics Treaty and such inventories have already been applied in the climate change field and as early evidence for a global legally binding agreement on mercury, eventually the Minamata Convention.