A race to zero - Assessing the position of heavy industry in a global net-zero CO2 emissions context

In this study, we explore the decarbonisation pathways of four carbon and energy-intensive industries (respectively iron & steel, clinker & cement, chemicals and pulp & paper) in the context of a global 2050 net-zero carbon emissions objective using the IMAGE integrated assessment model. We systematically test the robustness of the model by studying its responses to four different decarbonisation narratives and across six different world regions. The study underpins earlier conclusions in the literature on ‘residual emissions’ and ‘hard-to-abate sectors’, such as the persistence of residual emissions and the overall continued use of fossil fuels by heavy industries within the global 2050 net-zero context (with the pulp & paper sector as an exception). However, under the condition that net-negative emissions are achieved in the power and energy conversion sectors prior to the 2050 landmark, the indirect emission removals can compensate for the residual emissions left in the industry sectors, rendering these sectors ‘net-zero’ as early as the 2040s. Full decarbonisation of industrial (sub)sector(s) is found to be possible, but only under very specific narratives and likely outside of the 2050 timeline for the iron & steel, clinker & cement and the chemical sector. Subsequently, we find that the decarbonisation patterns in IMAGE are industry and regionally specific, though, different strategic considerations (narratives) did not substantially change the models’ decarbonisation response before or after 2050. Important aspects of the decarbonisation responses are the (direct and indirect) electrification of the iron & steel sector, a full dependency on carbon removal technologies in the clinker & cement sector, the closing of carbon and material loops in the chemical sector and zero-carbon heating for the pulp & paper sector. However, further research and modelling efforts are needed to study a broader palette of conceivable decarbonisation pathways and implications for industry within a global 2050 net-zero economy context.