Stabilising global CO2 emissions can be achieved at moderate costs
Mitigation policies: technological flexibility at moderate costs
How can the global energy system be transformed? What are the possible mitigation pathways? What are the associated costs? These are some of the questions being addressed within the ADAM project. The most remarkable early result is that stabilising global CO2 emissions can be achieved by different technological strategies at moderate costs. We report on the comparison of five energy-environment-economy models.
For this model comparison one common baseline scenario (e.g. GDP, CO2 emissions and energy consumption) was chosen to allow for comparability. To provide a more robust picture of the feasibility and mitigation costs of stabilisation, five energy-economy models were included which are different in their economic structure and assumptions. Moreover, a set of scenarios is run where certain technologies are fixed to the business-as-usual case in order to evaluate the option value of each respective technology. The stabilization target for this model comparison is – as a first step – a scenario stabilising at 550ppm CO2-eq.
The results of this model comparison show that: (i) all models can achieve the CO2 stabilization target at moderate costs; (ii) the models follow different strategies, for example concerning the energy mix to achieve this target; and (iii) the models themselves are flexible in their strategies.
Each of the models follows a different strategy to achieve the emission reductions, for example by reducing energy use, focusing on a large amount of renewables, or by placing the emphasis on a mix of carbon capture and storage (CCS) and renewables. By setting a restriction on a given technology, the models reveal high flexibility at reaching the target without that particular technology. In principle, every model can achieve the stabilisation target when either induced technological change due to climate policy or the amount of renewables, nuclear or CCS, are fixed to their baseline values.
This adaptability is mirrored in the mitigation costs. There are differences in costs between the models that range from a GDP gain of 0.6% to a GDP loss of 2.1% compared to the baseline scenario. The option values for the different technologies are not very pronounced; the differences within one model are generally less than one percentage point of GDP.
Whereas in the business-as-usual scenario the energy mix is dominated by fossil energy, the energy mix of the future shows more flexibility. This means that no single energy technology is irreplaceable to reach the mitigation targets. A mix of technology options is needed and the best strategy seems to be to support a broad portfolio of energy carriers. This result is consistent with the economic analysis.
For further information see Work Package M2 or contact: Brigitte Knopf, Potsdam Institute for Climate Impact Research,
