Pathways to Post-fossil Economy in a Well Below 2 ℃ World

We explore the pathways for mitigating climate change to at most 2 ℃ and below by imposing a representative target trajectory for radiative forcing and by range of different price trajectories for greenhouse gas emissions. Due to the inertia in both the energy and climate systems, it appears questionable whether the objective of limiting global warming to well-below 2 ℃ is achievable without considerably overshooting the target within the current century. Exceeding the constraints of the estimated carbon budget also means that the initial overshooting must be later compensated by removing the excess emissions with negative emissions, which may become very difficult without substantial technological changes leading the world into a sustainable post-fossil economy. We outline an idealised technology pathway aligning with these viewpoints. The analysis highlights the necessity for immediate mitigation action for avoiding excessive overshooting, the key role of negative emissions, and the prospects of producing synthetic fuels, chemicals and materials from renewables and carbon dioxide for enabling the transition into the post-fossil economy.