For the first time, researchers from ETH Zurich have calculated in absolute terms the extent to which the production of chemicals is currently affecting nature worldwide – and the results are staggering. In addition to greenhouse gas emissions, the new method also takes into account land use and fresh water consumption.
More than 99 percent of the most produced chemicals are unsustainable; their production is based on fossil raw materials and consumes more natural resources than the earth can provide in the long run. This is the conclusion of a sustainability analysis developed at ETH Zurich, which for the first time provides absolute statistics on the global environmental impact of the chemical industry.
“Our method compares the sources that consume chemicals with the ecological budget of our planet – this is a new approach,” says Gonzalo Guillén Gosálbez, Professor of Chemical Systems Engineering at ETH Zurich. He led the study, which was recently published in the journal Green Chemistrytogether with Javier Pérez-Ramírez, Professor of Catalysis Engineering at ETH.
Standard practice for sustainability assessments in the chemical industry today focuses on calculating the carbon footprint of a particular product – from raw material through production to disposal. Known as life cycle analysis, this enables a comparison between different types of production. However, it is of limited use in assessing global impacts on natural ecosystems.
Such conventional life cycle analyzes of chemicals often take only CO2 emissions accounted for, which hinders Pérez-Ramírez. “Climate change is not the only problem,” he says. “If we focus only on solutions that only reduce carbon emissions, we could actually end up shifting environmental burdens to other categories and causing some underlying damage.”
‘Green’ chemicals are not always sustainable
Pérez-Ramírez uses the example of biofuels to explain how such ecological damage can occur: when fossil fuels are replaced by plant-based raw materials such as corn or wood (known as first-generation biofuels), significantly less new CO2 is released into the atmosphere. However, large areas of arable land, a lot of water and also fertilizers are needed to produce the necessary biomass.
Therefore, the stated goal of the two researchers was to conduct a more comprehensive assessment of the life cycle for chemicals – and thereby make a direct connection to the earth’s ecological budget. They base their calculations on the so-called planetary boundaries. This scientific concept describes the influence of humans on nine important processes of the Earth system, such as loss of biodiversity and changes in land use.
In their study, the scientists calculated whether and to what extent the global production of a total of 492 chemicals exceeded seven of these limits. To this end, the ETH researchers link existing data and accounting models on raw material procurement, the supply chain and the various production steps at global level.
They found that more than 99 percent of the chemicals studied crossed at least one planetary boundary. However, according to this new method, only three of the chemicals can be considered environmentally sustainable in absolute terms.
Petroleum is the basic ingredient of chemicals
“The fact that almost all of the chemicals studied were harmful to the environment hardly surprised us,” says Pérez-Ramírez. After all, more than 85 percent of the basic carbon structure in which today most chemicals are still obtained from fossil raw materials.
“If the base chemicals are made from petroleum, then all the products made from them are also not sustainable,” says Pérez-Ramírez. The planetary boundaries that are strongly associated with anthropogenic greenhouse gases – climate change, ocean acidification and the integrity of the biosphere – are by far the ones that exceed chemicals the most.
But the authors of this work were surprised to find that some chemicals cross the Earth’s biophysical boundaries more than 100 times.
Towards sustainable production processes
It has long been recognized that the chemical industry must move away from the use of fossil raw materials. But now this study, for the first time, has quantified the problem on a global scale. “The message is clear: we can and must act now,” said Guillén Gosálbez.
In the advisory meetings that the ETH professor holds with chemical companies, they practically all show the willingness to make their production more environmentally friendly – also for economic reasons: “Sustainability has become a global trend and a topic that is paying more and more customers attention to, “says Guillén Gosálbez.
Bringing about a fundamental change in production processes is ultimately a matter of cost. “It is essential for companies to know in advance how many changes in a particular production step will increase the sustainability of their product,” explains Guillén Gosálbez. Until now, the industry has had few applications to conduct such an absolute sustainability evaluation.
Therefore, the researchers want to further develop their method so that it can not only be used to evaluate existing production processes, but also to optimize the potential of new approaches. “Ideally, this will allow us to find the best – that is, the most resource efficient – mix of the various production technologies for a chemical,” says Pérez-Ramírez.
Safe planetary boundary for pollutants, including plastic, exceeded, say researchers
Victor Tulus et al., Planetary metrics for the absolute assessment of environmental sustainability of chemicals, Green Chemistry (2021). DOI: 10.1039 / D1GC02623B
Citation: How the production of chemicals interferes with nature calculated in absolute numbers (2022, 1 February) Retrieved 1 February 2022 from https://phys.org/news/2022-02-production-chemicals-interfering-nature-absolute .html
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