Climate Economics Support for the UN Climate Targets
In this article researchers show that UN climate targets may be optimal even in the Dynamic Integrated Climate–Economy (DICE) integrated assessment model.
Abstract
Under the UN Paris Agreement, countries committed to limiting global warming to well below 2 °C and to actively pursue a 1.5 °C limit. Yet, according to the 2018 Economics Nobel laureate William Nordhaus, these targets are economically suboptimal or unattainable and the world community should aim for 3.5 °C in 2100 instead. Here, we show that the UN climate targets may be optimal even in the Dynamic Integrated Climate–Economy (DICE) integrated assessment model, when appropriately updated. Changes to DICE include more accurate calibration of the carbon cycle and energy balance model, and updated climate damage estimates. To determine economically ‘optimal’ climate policy paths, we use the range of expert views on the ethics of intergenerational welfare. When updates from climate science and economics are considered jointly, we find that around three-quarters (or one-third) of expert views on intergenerational welfare translate into economically optimal climate policy paths that are consistent with the 2 °C (or 1.5 °C) target.
Authors
Martin Hänsel
Potsdam Institute for Climate Impact Research, Leibniz Association, Potsdam, Germany
Moritz Drupp
Department of Economics and Center for Earth System Research and Sustainability (CEN), University of Hamburg, Hamburg, Germany
Daniel Johansson
Division of Physical Resource Theory, Department of Space, Earth & Environment, Chalmers University of Technology, Gothenburg, Sweden
Mark Freeman
York Management School, University of York, York, UK
Ben Groom
Department of Geography and Environment and Grantham Research Institute on Climate Change and the Environment, London School of Economics and Political Science, London, UK
