Material requirements and emission footprints of low-carbon technology diffusion

In 2015 the world agreed to combat climate change by taking efforts to keep the global temperature increase well below 2 degrees compared to pre-industrial levels. To keep global warming within the limit of 1.5 degrees,... [ view full abstract ]

In 2015 the world agreed to combat climate change by taking efforts to keep the global temperature increase well below 2 degrees compared to pre-industrial levels. To keep global warming within the limit of 1.5 degrees, actions to curb greenhouse gas emissions cannot be further delayed. The world cannot wait for some breakthrough technologies, that not only do not produce emissions, but hopefully also extract emissions from the atmosphere. What can be achieved in the short to medium run is a full exploitation of existing low-carbon technologies. That is, replacing all production processes with the best (in terms of emissions) currently available technology, or, in other terms, accelerating the diffusion of the low-emission technologies.

This change comes along with significant alterations in global production chains mainly brought about by different material inputs used in the production of the clean technologies and the inputs needed by these technologies for production. So far, when analyzing the impacts of low carbon transition pathways, generally the latter, that is the final outcomes (i.e. in-use emissions or emissions generated or materials used by using the new production technique) have been considered. Upstream environmental impacts of the capital requirements of this transition have been mostly neglected from the analysis.

Using multi-regional input-output (MRIO) analysis it is possible to analyze the diffusion of technologies from both perspectives in a consistent global framework. We present the findings regarding material and emission footprints of different low carbon technology diffusion scenarios until 2050. Special focus is given on the necessary capital investments in low-carbon technologies and the link to consumption in the world’s biggest economies.

To this end, a forward looking model with simple dynamics (EXIOfutures) is created based on the data from the MRIO database EXIOBASE. Existing scenarios, e.g. those designed for the IEA’s energy technology perspectives or the IPPC’s representative concentration pathways (RCPs) or shared socio-economic pathways (SSPs), are used to drive technological change in EXIOfutures. EXIOfuturesis not meant to perfectly forecast global economic development. Rather, given the existing scenarios or “states of the world” and EXIOfuturesshows how these can be reached using technological change and a change in consumption behavior. While emissions are expected to be consistently lower in the long run scenarios, amount and composition of materials used depend on the actual technologies used to realize the scenario. Emissions might increase in the short run as low-carbon technologies may have slightly higher embodied emissions associated with their production than their high-carbon counterparts. Nonetheless, with increasing diffusion of clean technologies, the gap between production-based and consumption-based emissions/material use will be reduced significantly in the long run. It won’t be closed completely, as OECD and EU countries continue to import a large share of their tangible consumption goods, while producing mostly less carbon intense services domestically.