Slow Onset Events

Strategic Workstream on Slow Onset Events
Expert Group on Slow onset events

Strategic workstream (a) of the current five-year workplan of the Warsaw International Mechanism Executive Committee (WIM ExCom) focuses on enhancing cooperation and facilitation in relation to slow onset events.

The impacts of climate change include slow onset events and extreme weather events, which may both result in loss and damage. Slow onset events, as initially introduced by the Cancun Agreement (COP16), refer to the risks and impacts associated with increasing temperatures, desertification, loss of biodiversity, land and forest degradation, glacial retreat and related impacts, ocean acidification, sea level rise, and salinization.

Work facilitated by the WIM ExCom on this workstream

The WIM ExCom has been conducting a number of activities since 2015, including under strategic workstream (a) of its five-year rolling workplan, to improve the state of knowledge to understand and the capacity to address slow onset events and their impacts.

The Expert Group on Slow onset events helps execute the work of the WIM ExCom in guiding the implementation of the Warsaw International Mechanism in an advisory role.

Resources under the workstream on slow onset events

Improving the state of knowledge on loss and damage associated with slow onset events

The WIM ExCom published a technical guide on sea level rise in 2025, developed in collaboration with its expert group on slow onset events. The guide discusses the risks and impacts of observed and projected rising sea levels on communities and the environment. It features a range of approaches from case studies, including protective measures such as coastal armouring, flood barriers, and elevating structures, alongside nature-based solutions, accommodation strategies and managed retreat for at-risk communities.
The WIM ExCom collaborated with the publisher Elsevier to respond to the growing need to enhance the understanding of the adverse effects of slow onset events on vulnerable populations and relevant approaches for addressing them. The special issue of the journal Current Opinion in Environmental Sustainability on slow onset events related to climate change was published in 2021.
A technical paper on slow onset events, drawing on the discussions from regional expert meetings held under the SBI work programme on loss and damage (Nov 2012), provides an overview of the eight types of slow onset events as identified in the Cancun Adaptation Framework and associated approaches to address loss and damage associated with the adverse effects from those events.

Information on organizations working on slow onset events

A database of organizations that are working on one or more of the eight types of slow onset events. The database, created in 2014 and updated on a rolling basis, also serves as an information base for ExCom’s work on slow onset events to further strengthen dialogue, coordination, coherence and synergies among stakeholders.
See an overview of the scope of work undertaken by those organizations and the mapping details conducted in 2018.
The report of the expert meeting, held in 2013, to consider future needs, including capacity needs associated with possible approaches to address slow onset events.

Awareness-raising activities under the workstream on slow onset events

A photo campaign on slow onset events and COP 23 side event on “Breaking new ground: Risk financing for slow onset events” to share information on features of financial instruments and innovative ways to engage in collaboration and partnerships for enhancing action and support for addressing the risks of slow onset events. (a summary, presentations)
Furthering the link between science and the policy process
- Letter to the Chair of the SBSTA requesting to consider slow onset events as a possible topic for the research dialogue to be held at SBSTA 44
- Posters on slow onset events showcased at the 8^th Research Dialogue at SBST 44 (poster 1, poster 2)

The work of the Expert Group on Slow onset events supports strategic workstream (a) of the five-year rolling workplan of the Warsaw International Mechanism Executive Committee (WIM ExCom), which aims to enhance cooperation and facilitation in relation to slow onset events.

The Expert Group currently focuses its technical work on desertification, glacial retreat and sea level rise. Four members of the WIM ExCom facilitate the work of the group.

Establishment of the Expert Group on Slow Onset Events

The COP, at its twentieth session in 2014, decided that the WIM ExCom may establish expert groups, subcommittees, panels, thematic advisory groups or task-focused ad hoc working groups to help execute the work of the ExCom in guiding the implementation of the Warsaw International Mechanism, as appropriate, in an advisory role, and that report to the ExCom (Decision 2/CP.20, para 8). ExCom 12 (2020) adopted the terms of reference for the Expert Group on Slow onset events, and the group held its first meeting in 2021.

Plan of Action

The WIM ExCom endorsed the second Plan of Action of the Expert Group on Slow onset events at ExCom 20 (2024). Recognizing the far-reaching impacts of slow onset events on livelihoods and economies, which can manifest simultaneously in different territories and landscapes, the second plan of action continues the work undertaken during the first rolling plan of action on selected water-related slow onset events: glacial retreat, sea level rise, and desertification. The Plan identifies actions that will contribute to the implementation of strategic workstream (a) of the five-year rolling workplan of the WIM ExCom.