Lamontagne’s study defines tolerable economic conditions as follows: the present value of abatement costs would not exceed 3% of gross world product and climate damages would not exceed 2% of gross world product. Current gross world product is estimated to be$80trillion, so 3% of that would be $2.4 trillion. Although this a large dollar amount, it would be a reasonable investment as a percentage of gross world product. Tolerable climate is defined as limiting warming by 2 degrees Celsius by 2100.
Abatement costs that range between 3% and 5% of global world product would be considered both aggressive and yet also uncertain in terms of limiting warming. However, because not taking action guarantees failure, immediate action is the best shot at having a tolerable future. The cost of alternative energy sources and how quickly abatement efforts take placewill determine the eventual, actual cost. In addition, actions that are important for the climate in the near term will not be important fifty or a hundred years on. Whatever climate abatement initiatives we undertake today, and which will surely be expensive, will primarily benefit future generations.
The study used a model that explored 5.2 million alternative scenarios. Limiting warming to 2 degrees Celsius is possible, but only feasible in the most optimistic scenarios. Further, the analysis shows that in order to have at least a 50 percent chance of achieving a tolerable climate and economic future, net zero CO2 emissions need to be reached by the year 2030. The window for action is narrow: time is running out to reduce emissions and avert really significant climate impacts.
Jonathan Lamontagne is assistant professor of civil and environmental engineering at Tufts University School of Engineering. He researches water resources, decision-making under uncertainty, hydrologic statistics, and integrated global change assessment. His study, Robust abatement pathways to tolerable climate futures require immediate global action,was published in Nature Climate Change.
He received his M.S. and Ph.D. in environmental water resources systems analysis from Cornell University. His graduate studies focused on flood frequency analysis and the incorporation of uncertainty in hydropower systems planning. Following his graduate studies, Lamontagne worked as a postdoctoral research associate at Cornell University, studying uncertainty and robustness issues for models of the integrated human-climate system. He joined the Tufts Department of Civil and Environmental Engineering in 2017.
Follow Jonathan Lamontage on Twitter @jr_lamontagne and Tufts University School of Engineering @TuftsEngineer.