Scenarios for a 2 °C world: a trade-linked input–output model with high sector detail

Abstract

In this study a scenario model is used to examine if foreseen technological developments are capable of reducing CO₂ emissions in 2050 to a level consistent with United Nations Framework Convention on Climate Change (UNFCCC) agreements, which aim at maximizing the temperature rise to 2 °C compared to pre-industrial levels. The model is based on a detailed global environmentally extended supply–use table (EE SUT) for the year 2000, called EXIOBASE. This global EE SUT allows calculating how the final demand in each region drives activities in production sectors, and hence related CO₂ emissions, in each region. Using this SUT framework, three scenarios have been constructed for the year 2050. The first is a business-as-usual scenario (BAU), which takes into account population, economic growth, and efficiency improvements. The second is a techno-scenario (TS), adding feasible and probable climate mitigation technologies to the BAU scenario. The third is the towards-2-degrees scenario (2DS), with a demand shift or growth reduction scenario added to the TS to create a 2 °C scenario. The emission results of the three scenarios are roughly in line with outcomes of typical scenarios from integrated assessment models. Our approach indicates that the 2 °C target seems difficult to reach with advanced CO₂ emission reduction technologies alone.

Policy relevance

The overall outlook in this scenario study is not optimistic. We show that CO₂ emissions from steel and cement production and air and sea transport will become dominant in 2050. They are difficult to reduce further. Using biofuels in air and sea transport will probably be problematic due to the fact that agricultural production largely will be needed to feed a rising global population and biofuel use for electricity production grows substantially in 2050. It seems that a more pervasive pressure towards emission reduction is required, also influencing the basic fabric of society in terms of types and volumes of energy use, materials use, and transport. Reducing envisaged growth levels, hence reducing global gross domestic product (GDP) per capita, might be one final contribution needed for moving to the 2 °C target, but is not on political agendas now.

Keywords:

• scenario
• supply–use tables
• technology development

Acknowledgements

We thank three anonymous reviewers for their comments and suggestions, which greatly improved this manuscript. This work was supported by EU grant agreement no. 308680.under the FP7 call ENV.2012.6.1-4: Exploiting the full potential of economic instruments to achieve the EU's key greenhouse gas emissions reductions targets for 2020 and 2050.

Notes

1. As the study started before Croatia joined the EU, the EU is defined here as the EU27.

2. South Africa is part of the BRICs while all other African countries are part of the RoW.

3. The software repository can be found at the website of Leiden University (http://cml.leiden.edu/research/industrialecology/researchprojects/projects/cecilia.html).