Science: Changes in waste management could buy us time to tackle the climate crisis

Although industry, transport, and energy are the most talked about sectors in the climate crisis and emissions context, one sector was somewhat neglected: solid waste. An international team of scientists pointed out in the Science journal that changes in solid waste management could even temporarily slow down the warming of the planet, saving us some time to deal with the climate crisis. Yee Van Fan from the Faculty of Mechanical Engineering at Brno University of Technology was also involved in the research.

„Why do we focus on waste management? It is not the major greenhouse gas emitter compared to the energy and transportation sectors. However, organic waste generates a significant amount of methane. Methane, compared to carbon dioxide, has a warming potential 84 times higher than CO2. Even after one hundred years, it still has a warming potential of 28 times higher,“ emphasizes co-author of the study Yee Van Fan from Sustainable Process Integration Laboratory (SPIL), Brno University of Technology.

According to the study, if we are able to maintain the methane emissions constant, the warming caused by them will be constant as well. On the contrary, even if the CO2 emissions are constant, the warming effect will still increase. „But if we are able to decrease the methane emission, it could actually give us a cooling effect. This is why we are targeting methane reduction as a near-term solution because it can buy us some time to deal with CO2 emissions and climate crisis,“ adds Fan.

The paper published in Science is a collaborative work of researchers from Malaysia, South Korea, and the Czech Republic. The multidisciplinary nature of the topic required scientists with different backgrounds: environmentalists, mathematicians, and economists. The predictions in the model are based on historical data, taking into account 43 countries that are responsible for 86 % of global solid waste production (in 2016). In addition to a four-page paper, the researchers provided about 40 pages of supplementary materials. The paper stressing the urgency of the waste management situation is a first-of-its-kind study and was chosen as a cover topic of Science published on 17 November.

The researchers linked the study's calculations to two climate targets: the Paris Agreement’s 1.5° and 2°C pathway goals and the terms of the Global Methane Pledge, a plan to cut methane emissions by 30 % in 2050. The study results are both hopeful and cautionary: by combining the right set of waste management strategies, mankind has a chance to reduce methane emissions enough to reverse the global warming trend temporarily. At the same time, these big changes must be implemented quickly (between 2033 and 2041 at the latest, according to the study), which is a huge challenge.

The authors tried to forecast solid waste growth under different scenarios, based on e.g. population and GDP growth. To this, they linked the GHG emissions forecast in five scenarios. „If we implement no changes, meaning we will follow current waste treatment strategies, you can see that around 2045, we will exceed the 2°C target,“ says Fan.

Several strategies are shown to combat the methane emissions produced by solid waste: digesting organics, halving waste, composting organics, and retrofitting landfills. „Behavioural changes are important: how we will change our lifestyle to reduce waste production. Technology is another important aspect; we need to change waste management from a linear economy into a circular economy,“ stresses Fan.

The article in the journal Science can be accessed on the web here.

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Published	2023-12-06
Link	https://www.vut.cz/en/sustainability/f38144/d249960