Science Goals

TiPES has 7 scientific work packages (WP) that all combine to better understand past and present tipping points in the earth system, but also aim to make sure that the knowledge is passed to politicians, the general public and other stakeholders.

Themes

Apart from work packages, TiPES has 4 themes and a number of specific project objectives as listed.

Theme 1– Tipping elements in data and models

Theme 2 – Climate response theory

Theme 3 – Mathematics of tipping points

Theme 4 – Data and decisions

Project Objectives

Objective 1 (O1). Identify tipping elements (TEs) and their interactions in models and data

Specific Objective 1.1. Develop a self-consistent framework of abrupt climate changes in proxy reconstructions of past climates. This framework should include results from a hierarchy of models, from low-order to highly detailed ones, and be supported by paleoclimate archives evidencing abrupt climate transitions in the past.

Specific Objective 1.2. Identify and better characterize previously hypothesized TEs in the Earth system and their associated TPs in terms of critical forcing levels. This will involve modelling and paleoclimatic reconstructions of past warm and cold climates, with particular focus on interactions between the different TEs, along with any potentially cascading or stabilising effects these interactions may cause.

Objective 2 (O2). Provide approaches for the identification and validation of Early Warning Signals (EWSs)

Specific Objective 2.1. Develop methods to skillfully predict forthcoming TPs beyond simple statistical EWSs. This work will focus on the interactions between different TEs and complement statistical precursors of forthcoming transitions and cascades thereof by physics-based ones.

Objective 3 (O3). Characterise climate response in the presence of Tipping Points (TPs)

Specific Objective 3.1. Develop a theory of Climate Response (CR) that goes beyond linear and equilibrium concepts, i.e. beyond Equilibrium Climate Sensitivity (ECS). This theory should deal with responses on distinct temporal and spatial scales, and relate the responses of different observables to external forcing through appropriate response operators.

Specific Objective 3.2. Apply and evaluate this CR theory by deriving thresholds associated with both natural and anthropogenic abrupt and irreversible transitions in both warmer and colder climates, using information from appropriate paleoclimate data and climate models.

Objective 4 (O4). Define and identify safe operating spaces

Specific Objective 4.1. Estimate the safety of operating spaces in terms that are quantitatively related to well-defined notions of bifurcations and attractors, as well as to global notions of stability for non-autonomous systems subject to time-dependent forcing.

Specific Objective 4.2. Develop quantitative estimates for the boundaries of safe operating spaces and the associated uncertainties in terms of critical levels and rates of change of distinct anthropogenic forcings. Assess the likelihood of abrupt transitions in the vicinity of these boundaries, while taking into account concepts such as noise- and rateinduced tipping.

Objective 5 (O5). Bridge the gap between climate science and policy advice

Specific Objective 5.1. Develop a clear formal language (domain-specific language) to communicate concepts and connections between TP researchers and decision-makers. This includes the notions of uncertainty about the consequences of crossing specific TPs, the reliability of EWSs, and the size and shape of safe operating spaces. The objective of the domain-specific language is to stand as a reference and to minimize ambiguity in the communication of research outputs.

Specific Objective 5.2. Understand the impact of uncertainties on TPs for the mathematical problem of finding optimal policy mechanisms, and frame the dialogue with the decision-maker for defining and communicating decision problems, which determine accountable policies.