The transformation of industries and the carbon issue have reached a global consensus: in 2021 over 130 countries and 110 regions have set a goal of achieving carbon neutrality, equivalent to around 88% of global greenhouse gas emissions. The key to this lies primarily in low-carbon energy systems and a sophisticated circular economy. According to the International Energy Agency, the demand for mineral resources for clean energy technologies will increase four- to six-fold if the goal of limiting the global temperature rise to below 2 °C is to be achieved. In this context, the extraction of strategic metals such as aluminium, copper and nickel will also be crucial for the transition to clean energy. But above all, governments and industry organisers should take active measures to stimulate aluminium companies to develop technologies to improve the efficiency of aluminium use and reduce carbon emissions.

Against this background, carbon emissions within the aluminium cycle become an integral part of the analysis of the relationship between aluminium and the economy.

The development of clean energy and low-carbon technology has already led to greater demand for aluminium: Aluminium is used as an indispensable raw material in construction, packaging, transportation, electrical engineering, aerospace and other sectors. The International Aluminium Institute reports that the annual growth rate of aluminium demand could reach 33 million tonnes worldwide by 2030. The World Bank estimates that the cumulative demand for aluminium in low-carbon technology will exceed around 800 million tonnes by 2050. Demand for aluminium in photovoltaics is estimated to increase to 486 million tonnes by 2050.

According to the China Nonferrous Metal Industry Association, China has been the world's largest aluminium consumer since 2006. In 2021, aluminium consumed in China accounted for 60% of global aluminium consumption. Clearly, China is relatively dependent on aluminium resources for its future development. However, the contradictions between the huge demand, high dependence on aluminium resources (external dependence ratio of over 56.88% in 2020), low resource efficiency and high emissions in production are obvious in China. According to the China Nonferrous Metals Industry Association, carbon emissions from aluminium extraction, refining and smelting will account for about 6 % of gross domestic emissions in 2020. Aluminium production generated far more carbon emissions than other non-ferrous metals.

Under the double pressure of the contradiction between supply and demand and the goal of emission reduction, it is necessary to analyse the fuzzy relationship between economic growth and aluminium consumption or aluminium-related carbon emissions: Driven by the need for clean energy and low-carbon transformation in industry, increasing aluminium demand adds to this fuzziness. An integrated decoupling model for aluminium consumption and carbon emissions in the context of the anthropogenic aluminium cycle will further explore this issue – previous studies have already proposed the concept of decoupling to express the relationships between resource use or environmental impacts and economic growth. Decoupling theory states that resource use or environmental impacts increase with economic growth at the beginning of industrialisation. This trend then reverses after a certain point.

As part of the research, the first step was to conduct a material flow analysis (MFA) for the period 2000-2020 for China's aluminium cycle to quantify both aluminium flow and carbon emissions in each life cycle process of aluminium. Then, the decoupling index of aluminium use and carbon emissions was assessed and decomposed using the LMDI decomposition model. The results show, firstly, that secondary aluminium has not become an effective complement to primary aluminium in China and, secondly, that the expansive negative decoupling state is the most widespread state. The decoupling effects of carbon emissions were also better than those of aluminium consumption. Technology improvements were also an important factor in the decoupling process - but these were mostly unable to offset the growth in aluminium consumption or carbon emissions.

This is an excerpt from the article „Decoupling analysis between economic growth and aluminum cycle: From the perspective of aluminum use and carbon emissions“ from the Journal of Environmental Management (Elsevier, Autoren Ying Chen, Xuehong Zhu, Anqi Zeng). Original text, resources and further information can be found here: https://www.sciencedirect.com/science/article/abs/pii/S0301479723012495