Open Access

Daniel Callies, Darrel Moellendorf

• With the significant disconnect between the collective aim of limiting warming to well below 2°C and the current means proposed to achieve such an aim, the goal of this paper is to offer a moral assessment of prominent alternatives to current international climate policy. To do so, we’ll outline five different policy routes that could potentially bring the means and goal in line. Those five policy routes are: (1) exceed 2°C; (2) limit warming to less than 2°C by economic de-growth; (3) limit warming to less than 2°C by traditional mitigation only; (4) limit warming to less than 2°C by traditional mitigation and widespread deployment of Negative Emissions Technologies (NETs); and (5) limit warming to less than 2°C by traditional mitigation, NETs, and Solar Radiation Management as a fallback. In assessing these five policy routes, we rely primarily upon two moral considerations: the avoidance of catastrophic climate change and the right to sustainable development. We’ll conclude that we should continue to aim at the two-degree target, and that to get there we should use aggressive mitigation, pursue the deployment of NETs, and continue to research SRM.