Time to act now? Assessing the costs of delaying climate measures and benefits of early action

摘要: This paper compares the results of three state art climate-energy-economy models IMACLIM-R, ReMIND-R, and WITCH to assess costs climate change mitigation in scenarios which implementation a global agreement is delayed or major emitters decide participate at later stage only. We find that for stabilizing atmospheric GHG concentrations 450 ppm CO2-only, postponing 2020 raises by least about half delay 2030 renders ambitious targets infeasible achieve. In standard policy scenario—in allocation emission permits aimed equal per-capita levels year 2050—regions with above average emissions (such as EU US alongside rest Annex-I countries) incur lower taking early action, even if efforts world experience delay. However, regions low are net exporters India) can possibly benefit from higher future carbon prices resulting illustrate economic mechanism behind these observations analyze how (1) lock-in intensive infrastructure, (2) differences prices, (3) changes reduction commitments action influence costs.