Cardboard packaging, already the most sustainable material for cartons, has reduced its carbon footprint according to a study carried out by a leading Swedish research organisation.
The Carbon Footprint of Carton Packaging 2023 was commissioned by Pro Carton and carried out by the Research Institute of Sweden (Rise) and the data checked by the Institut für Energie und Umweltforschung in Heidelberg.
The headline finding is that the carton board and carton converting industry had combined to reduce the cradle to grave carbon footprint of cartons by 24% over a similar study in 2018. GHG emissions due to fossil fuels dropped 17% since the previous study.
The main reason is investment in renewable energy, both on site and from the grid, supported by investment in more energy efficient plant and machinery. The study assesses only the weight of cartons, not any additional benefits from light weighting or changes to structural design to reduce the amount of material needed for each unit.
The research looked at both the cradle to gate and the cradle to grave carbon impact using data collected in 2021. This included carbon from both fossil fuel and biogenic greenhouse gas emissions, typically from biomass generation at paper mills.
The cradle to grave calculation produced a carbon footprint go 249kg CO2 per tonne of cartons and a cradle to gate impact of 148kg for the tonne of cartons. The study balanced the total amount of carbon released against the beneficial impacts of forest management to produce the next crop for pulp and board.
Pro Carton celebrates the results saying that this underlines the circularity leadership of carton board as a packaging material, backed by science based studies, which is increasingly important to converters, brands and retailers and ultimately consumers.
The figures will also help individual converters improve their performance, says pro carton director general Horst Bittermann. “Our members can compare their own data against industry averages and evaluate how their tremendous efforts to further improve energy efficiency, to use renewable energy sources and to upgrade internal processes to the latest state of the art, have paid off. The cradle to gate value of 148kg CO2 is a substantial improvement on our way to a low or even carbon neutral, bio based economy and reflects process improvements and the investments taken by the industry.”
As well as energy used to make the pulp and the board, which amounts to the majority of the carbon released, the study took into account glues, inks, varnishes and laminates that might be used in the converting process. Printing accounts for 18% of the cradle to gate impact while transport from mill to converter is 5% of the impact.
