Landfills are responsible for planet –warming, say experts

By Our Special Correspondent

A study suggests that landfills are releasing significant amounts of planet-warming methane into the atmosphere from decomposing waste.

Scientists used satellite data from four major cities around the world — Delhi and Mumbai in India, Lahore in Pakistan, and Buenos Aires in Argentina — and found that city-level emissions in 2018 and 2019 were 1.4 to 2.6 times higher than previous estimates.

The study, published in Science Advances on Wednesday, aims to help local governments organize targeted efforts to limit global warming by identifying specific sites of major concern.

When organic waste such as food, wood or paper decomposes, it releases methane into the air. Landfills are the third-largest source of methane emissions worldwide, after oil and gas systems and agriculture.

Methane makes up only 11% of greenhouse gas emissions and persists in the air for about a dozen years, but it traps 80 times more heat in the atmosphere than carbon dioxide. Scientists estimate that at least 25% of today's warming is driven by methane from human activities.

"This is the first time that high-resolution satellite images have been used to observe landfills and quantify their methane emissions," said Jones Massackers, lead author of the study and a climate scientist at the Netherlands Institute for Space Research.

"We found that these landfills, which are relatively small compared to city sizes, account for a large portion of the total emissions from a given area," he said.