The Economics of Low Stabilization: Model Comparison of Mitigation Strategies and Costs

TLDR

The study synthesizes a model comparison evaluating the technological feasibility and economic impacts of meeting low greenhouse gas concentration targets that limit warming to below 2 °C. All five models confirm that low GHG concentration targets are technically feasible and economically viable, with bio‑energy plus CCS essential for the 400 ppm pathway and aggregate costs staying below 0.8 % of global GDP for 550 ppm and below 2.5 % for 400 ppm by 2100.

Abstract

This study gives a synthesis of a model comparison assessing the technological feasibility and economic consequences of achieving greenhouse gas concentration targets that are sufficiently low to keep the increase in global mean temperature below 2 degrees Celsius above pre-industrial levels. All five global energy-environment-economy models show that achieving low greenhouse gas concentration targets is technically feasible and economically viable. The ranking of the importance of individual technology options is robust across models. For the lowest stabilization target (400 ppm CO2 eq), the use of bio-energy in combination with CCS plays a crucial role, and biomass potential dominates the cost of reaching this target. Without CCS or the considerable extension of renewables the 400 ppm CO2 eq target is not achievable. Across the models, estimated aggregate costs up to 2100 are below 0.8% global GDP for 550 ppm CO2 eq stabilization and below 2.5% for the 400 ppm CO2 eq pathway.