Technological options are critical for economic viability of 2°C climate target
Tapping renewable energy sources, capturing and storing of industrial emissions of carbon dioxide and improving energy efficiency are pivotal for holding the increase in global temperature below 2°C. In a special issue of “The Energy Journal”, a team of researchers of the Potsdam Institute for Climate Impact Research (PIK) and four other European institutions reports that atmospheric concentrations of greenhouse gases can be stabilized at correspondingly low levels at moderate costs.
Dependency on specific technologies increase
However, costs, as well as the dependency on specific technologies, increase with the chances to achieve the 2°C target. “We have started from the assumption of a ‘first-best’ world where current and newly developed technologies are fully available,” says Ottmar Edenhofer, chief economist at PIK. “However, we have also investigated a ‘second-best’ world where some of the technologies are not available or have a limited potential,” adds the lead author of the article ‘The Economics of Low Stabilization: Model Comparison of Mitigation Strategies and Costs’. The scientists found that the costs of mitigation are substantially higher or that ambitious climate targets are actually unattainable in the second-best world.
Adaptation and mitigation strategies
As part of the EU-funded project “Adaptation and mitigation strategies: supporting European climate policy” (ADAM) the researchers have explored the technological options for reaching three different stabilization levels of atmospheric greenhouse gases. These correspond to carbon dioxide concentrations of 550, 450, and 400 parts per million (ppm) with a 15, 50, and 75 percent chance, respectively, to achieve the 2°C target. The scientists used five state-of-the-art energy-environment-economy models to illustrate the technological and economic scenarios and systematically compared the results.
Models provide technology pathways
“The models provide a number of technology pathways that have a high likelihood of achieving the 2°C target,” says Brigitte Knopf, the scientific coordinator of the ADAM model comparison. All models achieved the low stabilization at 400 ppm at moderate costs. Expressed as aggregated gross domestic product losses until 2100, the global mitigation costs are reported to be below 2.5 percent. But this requires a portfolio of technologies, the researchers found.
No silver bullet to tackle climate change
“There is no silver bullet to tackle climate change, but, interestingly, the models agree on the ranking of importance of energy technologies,” says Knopf. Without either carbon capture and storage (CCS) or the expansion of renewable energy beyond business-as-usual, stabilization of atmospheric greenhouse gases becomes significantly more expensive. Ambitious climate mitigation targets might not be achieved at all. In one model, the extensive use of biomass for heat and power production was another essential option for the feasibility of the low stabilization level. In two other models, costs doubled with a limitation of biomass use to a sustainable potential.
Effect of nuclear energy as a mitigation option is limited
In contrast, the effect of nuclear energy as a mitigation option is limited as refraining from the expansion of nuclear energy is possible at almost no additional costs. Furthermore, the models show that even a global phase out of nuclear energy is possible at slightly increased mitigation costs. “It is clear that a model analysis alone cannot address the full range of economic, political and risk management issues raised by the use of some of the technologies,” says Knopf.
Potential risks of CCS
The feasibility and potential risks of CCS, for example, are largely unknown today and also to what extent the extensive use of biomass would compete with food production and nature conservation. But the study does indicate clearly that the development of a portfolio of technologies is crucial in order to keep mitigation costs low, paving the way for a global climate agreement.
Go to Potsdam Institute for Climate Impact Research