Sebastiaan Deetman

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

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.

The impact of technology availability on the timing and costs of emission reductions for achieving long-term climate targets

While most long-term mitigation scenario studies build on a broad portfolio of mitigation technologies, there is quite some uncertainty about the availability and reduction potential of these technologies. This study explores the impacts of technology limitations on greenhouse gas emission reductions using the integrated model IMAGE. It shows that the required short-term emission reductions to achieve long-term radiative forcing targets strongly depend on assumptions on the availability and potential of mitigation technologies. Limited availability of mitigation technologies which are relatively important in the long run implies that lower short-term emission levels are required. For instance, limited bio-energy availability reduces the optimal 2020 emission level by more than 4 GtCO2eq in order to compensate the reduced availability of negative emissions from bioenergy and carbon capture and storage (BECCS) in the long run. On the other hand, reduced mitigation potential of options that are used in 2020 can also lead to a higher optimal level for 2020 emissions. The results also show the critical role of BECCS for achieving low radiative forcing targets in IMAGE. Without these technologies achieving these targets become much more expensive or even infeasible.

Deep CO2 emission reductions in a global bottom-up model approach

Most studies that explore deep GHG emission reduction scenarios assume that climate goals are reached by implementing least-cost emission mitigation options, typically by implementing a global carbon tax. Although such a method provides insight into total mitigation costs, it does not provide much information about how to achieve a transition towards a low-carbon energy system, which is of critical importance to achieving ambitious climate targets. To enable sensible deep emission reduction strategies, this study analysed the effectiveness of 16 specific mitigation measures on a global level up to 2050, by using an energy-system simulation model called TIMER. The measures range from specific energy efficiency measures, like banning traditional light bulbs and subsidizing electric vehicles, to broader policies like introducing a carbon tax in the electricity sector. All measures combined lead to global CO2 emission reductions ranging between 39% and 73% compared to baseline by 2050, depending on the inclusion of sectoral carbon taxes and the availability of carbon capture and storage (CCS) and nuclear power. Although the effectiveness of the measures differs largely across regions, this study indicates that measures aimed at stimulating low-carbon electricity production result in the highest reductions in all regions.Policy relevanceThe results of the calculations can be used to evaluate the effects of individual climate change mitigation measures and identify priorities in discussions on global and regional policies. The type of fragmented policy scenarios presented here could provide a relevant bottom-up alternative to cost-optimal implementation of policies driven by a carbon tax. We identify overlapping and even counter-productive climate policy measures through an analysis that presents the policy effectiveness by region, and by sector. The set of 16 policy measures addresses the largest emitting sectors and represents options that are often discussed as part of planned policies.

Deriving European Tantalum Flows Using Trade and Production Statistics

Even though tantalum has a high economic importance and is associated with armed conflict, the use of tantalum throughout the supply chain of importing economies is not well understood. This article adds to existing qualitative descriptions of the tantalum supply chain by performing a quantified substance flow analysis (SFA) of tantalum for Europe in the year 2007. The exercise is meant to show how readily available statistical information could be used along with simple and transparent assumptions on product composition and allocation, to yield an enabling and visual representation of the supply chain for critical materials. The case of tantalum shows some surprising results. First of all, this study shows that tantalum in computer hard disks and artificial joints may be more relevant than found in previous studies. Further, we find that the tantalum consumption in Europe may be larger than expected based on geological survey reports, attributed to a high fraction of tantalum being imported in subcomponents and final products. Further research is needed to substantiate this claim, but what is clear is that a detailed SFA provides valuable insights into the consumption of tantalum as a critical material, throughout the stages in the supply chain related to the production and use of tantalum‐containing products. The exercise also allowed production of waste generation profiles and enabled identification of e‐waste as an important focus group in order to improve tantalum recycling rates and eventually to reduce societys dependence on scarce or conflict‐related raw materials.

Regional differences in mitigation strategies: an example for passenger transport

This paper shows the importance of including region-specific circumstances in long-term climate change mitigation strategies, by example of a modeling exercise of the transport sector. Important emission reduction options in the transport sector include biofuels, electric vehicles and efficiency standards. The most effective combination of these options depends, among others, on the availability of biofuels, the effectiveness of efficiency standards, and the (expected) emission intensity of the power sector—all of which differ between regions. Differences in climate policies between regions influence these factors. For instance, fuel efficiency standards slowdown the long-term transition in regions where plugin hybrid electric cars compete with gasoline cars (such as the USA or Europe) by decreasing the costs for driving gasoline costs and therefore in fact increase long-term emissions. Another example is that promoting electric vehicles is less effective in regions which are expected to rely heavily on fossil fuels for power generation, such as South Africa, China and India. Based on these findings from the TIMER energy model, we introduce an indicative region-specific framework for assessing mitigation strategies for the transport sector up to 2050, for different ambition levels of climate policy.

Scenarios for Demand Growth of Metals in Electricity Generation Technologies, Cars, and Electronic Appliances

This study provides scenarios toward 2050 for the demand of five metals in electricity production, cars, and electronic appliances. The metals considered are copper, tantalum, neodymium, cobalt, and lithium. The study shows how highly technology-specific data on products and material flows can be used in integrated assessment models to assess global resource and metal demand. We use the Shared Socio-economic Pathways as implemented by the IMAGE integrated assessment model as a starting point. This allows us to translate information on the use of electronic appliances, cars, and renewable energy technologies into quantitative data on metal flows, through application of metal content estimates in combination with a dynamic stock model. Results show that total demand for copper, neodymium, and tantalum might increase by a factor of roughly 2 to 3.2, mostly as a result of population and GDP growth. The demand for lithium and cobalt is expected to increase much more, by a factor 10 to more than 20, as a result of future (hybrid) electric car purchases. This means that not just demographics, but also climate policies can strongly increase metal demand. This shows the importance of studying the issues of climate change and resource depletion together, in one modeling framework.

Strategic design of long-term climate policy instrumentations, with exemplary EU focus

The Paris climate goal requires unprecedented emission reduction, while CO2 concentrations are now rising faster than ever. Internally inconsistent instrumentation has developed on the go, not fit for deep reduction. Mainly national technology-specific instruments, for example, have made the EU pure cap-and-trade system superfluous and have fragmented electricity markets. Systematic instrumentation design requires an adequate categorization of instruments, newly developed here for that purpose. This instrument ordering links to generality and bindingness. Starting points for any instrumentation design are sparseness, completeness, and non-overlap. Details in instrumentations may further depend on specific circumstances in different countries and regions. Planning & Control starts with technology-specific instrumentation, with subsidies and standards to reduce fossil emissions in electricity production; effective Fleet Standards for transport; dynamic standards and permits regarding industry emissions; and standards and technology subsidies squeezing out fossils use in buildings and appliances. Subsidies create learning curves. Consistency and effectiveness tend to require centralization. Institutionalism uses two core institutional instruments. A comprehensive upstream emission tax with proceeds to the country or state level creates incentives. An open-to-all, real-time priced electricity market enables also small-scale renewables and secondary producers on the grid. Infrastructure is provided publicly. A level playing field results for mostly decentral climate action, both public and private. Policy relevance Technical instrument choices may seem neutral but cannot be so: policy is about choices. Two governance strategies are now mutually competing and counteracting. Planning & Control links to welfare theory and optimization, with broad integration of several policy goals, measurable targets, and deep public–private cooperation. Institutionalism has a background in history, economics, sociology, and political science, with institutions driving long-term development. Incentives and option creation are central, indicating results only roughly. There is strict public–private delimitation. These different views on governance lead to mutually exclusive sets of instruments. Explicit instrumentation strategies are required for consistency, effectiveness, and legitimacy. Internationally, Planning & Control requires binding country caps for (almost) all countries, UN-type. Institutionalism requires a limited agreement on a high rising emission tax, open for all countries to join a starting group, WTO-type. Choices are ultimately based on governance preferences.