Identifying the policy space for climate loss and damage.

C urrently planned greenhouse gas mitigation efforts would not prevent climate warming from going beyond 2°C as aspired to in the 2015 Paris Agreement (1), adding to climate-related impacts already under way (2). Although climate adaptation has been strengthened in the Paris Agreement, climate-related risks may exceed adaptation possibilities of communities and countries. To this effect, an important decision in the Paris Agreement was the endorsement of the Warsaw International Mechanism (WIM) for Loss and Damage (L&D) (3). This established L&D as a distinct pillar of climate negotiations, yet with an unclearly defined remit. With a policy framework yet to emerge, the 22nd Conference of the Parties (COP 22) of the United Nations Framework Convention on Climate Change (UNFCC) in November in Marrakesh will review the structure, mandate, and effectiveness of the WIM, first institutionalized in 2013. Risk science can provide a rationale and delineate a policy space for L&D, composed of curative measures for unavoided and unavoidable impacts, and transformative measures for avoiding and managing intolerable risks. Climate risks considered by the WIM are associated with extreme events—flooding, droughts, heat waves, and cyclones—and slow-onset impacts, including sea level rise and melting glaciers. Lacking official definition, losses have been associated with irreversibility—e.g., fatalities from climate events or households stuck in disaster-induced poverty traps, whereas damages refer to impacts that can be alleviated. A useful distinction has been made between avoidable, unavoided, and unavoidable L&D (4). Discussion of the WIM has been contested (5) and wide-ranging (6). The Alliance of Small Island States (AOSIS), whose members face substantial climate-related stress, initiated the debate more than two decades ago, proposing that parties with historically high emissions take responsibility via some sort of compensation instrument. With endorsement from other vulnerable developing countries, AOSIS has been arguing for an international mechanism basically made up of two components: support for risk management, including insurance efforts, and a rehabilitation or compensatory component addressing increasingly negative impacts (7). Many developed countries concur in principle on the need to help those suffering from climate change impacts but have been unwilling to accept notions of liability and have stressed the need to institutionalize incentives for tackling risks (8), as, for example, suggested by the 2015 Sendai Framework for Disaster Risk Reduction (DRR) (9). These parties suggested to cover the matter under adaptation, but the decision to have a standalone article of the Paris agreement (Article 8) refer to the WIM came about only after developing countries insisted that L&D is distinct. Vulnerable countries celebrated the inclusion of the WIM in the agreement, while developed countries managed to include assurance that the WIM does not provide a basis for liability and compensation, which remain important background issues informing any potential implications of the WIM.