The Intergovernmental Panel on Climate Change (IPCC) completed its Fifth Assessment Report on Sunday in Copenhagen. Ottmar Edenhofer, Co-Chair of the IPCC Working Group III ‘Mitigation of Climate Change’, and one of the authors of the now released Synthesis Report, points to the contrast between the potentially irreversible impacts of unmitigated climate change and the manageable costs of ambitious mitigation.
“Emissions of greenhouse gases are rising, rising, rising,” says Edenhofer, who is chief economist of the Potsdam Institute for Climate Impact Research (PIK) and director of the Berlin-based Mercator Research Institute on Global Commons and Climate Change (MCC). GHG emissions growth accelerated between 2000 and 2010 compared to the previous three decades.
“We are currently not on track to meet the agreed two degrees goal. And the more we delay the respective mitigation efforts, the greater the risks facing us will be – risks of climate impacts, but also the risks of mitigation,” explains Edenhofer.
The IPCC Synthesis Report shows that unabated climate change increases the likelihood of severe, pervasive and irreversible impacts. These include negative impacts for biodiversity, ecosystem services, and economic development and they amplify risks for livelihoods, and food and human security.
“Mitigation also entails risks,” Edenhofer points out. Open questions concern, for instance, the upscaling of electricity generation from biomass or carbon dioxide capture and storage, which is a technology untested at large-scale deployment. “But these risks are manageable, which is the fundamental difference to the potentially unmanageable risks of climate change,” Edenhofer continues.
The contribution of his Working Group to the Fifth Assessment Report shows that global economic growth is not strongly affected by climate policy. “There is no doubt that climate policy has its costs, but it does not cost the Earth to save the planet for our children,” says Edenhofer.
The economist regards carbon pricing as essential. “The atmosphere is a limited disposal that cannot be used for free,” Edenhofer underlines.
The Synthesis Report is the fourth and final contribution to the IPCC’s Fifth Assessment Report. In Copenhagen, its Summary for Policymakers has been approved. The contributions of the three IPCC Working Groups were published in autumn 2013 and spring 2014.