Uncertainties in the Earth System Response during and after a state of overshoot remain substantial and will determine the potential for reversing global warming. This session explores the Earth System’s transient responsestransition tothrough net zero and to net negative emissions, as well asand to Carbon Dioxide Removal (CDR). We seek to understand whether the Earth System responds differently to global net negative emissions compared to the period leading up to net zero, as these dynamics determine dictate peak temperatures, overshoot duration, and the effectiveness of CDR. CDR approaches vary widelybroadly, from regrowth of natural biomes to engineered extraction and ultimate storage of CO2 from the atmosphere. Each approach has its own unique challenges in terms of scalability, effectiveness, and durability of ultimate storage. In particular, resource requirements and environmental footprints may be limiting factors for future large-scale CDR deployment. In this session, we welcome submissions that improve improving our understanding of the Earth System response up to net zero and beyond, alongside strategies for sustainable CDR deployment. We invite contributions on whole Earth System perspectives, carbon cycle dynamics, and observational insights into climate overshoot. We particularly encourage research onexploring sustainable CDR scaling, mitigation trade-offs, and robust strategies to hedge against risks like carbon re-release. We also welcome submissions that bridgebridging these areas by examining both the Earth System’s physical responses and the enabling conditions or barriers related to markets, policy, finance, verification, and public perception.

As the world edges closer to breaching the 1.5°C threshold, technological innovation in decarbonisation and negative emissions is indispensable to managing climate overshoot. This session invites contributions on low-carbon and carbon-removal technologies capable of reducing, neutralising, and reversing cumulative emissions. We welcome submissions on the benefits and pathways of decarbonisation across highly emitting sectors, such as power, industry, and transport, as well as the built environment, buildings, infrastructure, and agriculture, alongside engineered and nature-based carbon dioxide removal (CDR) approaches. Studies examining techno-economic feasibility, co-benefits, scalability, and policy integration are particularly encouraged. The session aims to bring together engineers, economists, policy analysts, and researchers to assess which technological portfolios can credibly limit the magnitude and duration of overshoot, and how innovation, finance, and governance must align at scale. We also welcome submissions on the enabling conditions or barriers related to markets, policy, finance, verification, and public perception.

Achieving global temperature decline after exceeding 1.5C overshoot does not guarantee the reversal of local climate impacts. To further complicate the picture for policy-makers and practitioners, regional climate patterns will continue to change even under global temperature stabilization as Earth System components keep adjusting and equilibrating. Vulnerabilities and exposure dynamics in human and natural communities may differ substantially before and after overshoot, and will be affected by the extent and length of overshoot and the types of CDR deployed. This session tries to advance our understanding of key questions such as how a world after overshoot is different from a world without it, and for whom? What are the consequences of different overshot magnitudes and durations of exceedance? What are the benefits of long-term global warming reversal compared to stabilization at peak warming? Specific focus will be given to understanding irreversible impacts on human timescales—, i.e. in oceans, the bio- and cryosphere, and the already at risk ecosystems—. Beyond changing climate hazards, and the temporal interrelations of overshoot pathways beyond changing climate hazards. 

Overshoot will leave a long-lasting climate system legacy, in particular if nonlinear and irreversible dynamics of physical and ecological Earth System tipping elements were triggered during target exceedance. Emerging insights suggest that global warming reversal to levels below present-day may be required to limit tipping risks on centennial timescales. Yet, there is still limited understanding of how the climate system behaves after reaching net-zero CO2 emissions and if declining global mean temperatures can be achieved at the required scale. Also, temporal dynamics and reversibility of potential tipping elements under those conditions are not well understood. This session welcomes contributions that shed light on  the legacy of committed climate changes and dynamics of global tipping elements, threshold responses and other nonlinear and abrupt changes under global temperature peak and decline pathways. Specific focus will be put on determining long-term consequences of near-term climate (in)action up to peak warming, and the possibilities and limits of reducing long-term risks by reversing global warming.

Overshoot pathways fundamentally reshape the timing, magnitude and distribution of climate‑attributable health risks, with peak temperature, duration of overshoot and rate of decline jointly determining the overshoot health penalty. This theme focuses on quantifying how alternative overshoot profiles translate into changes in mortality, morbidity, and health system stress through pathways such as heat, air pollution, undernutrition, infectious diseases and extreme events, and on attributing these changes to physical and socioeconomic drivers alongside overshoot, peak and decline pathways. We invite contributions that explicitly link overshoot pathway characteristics to health outcomes using tools including epidemiological models, impact functions, integrated assessment models, and health burden projections. Key questions include: How sensitive is the overshoot health penalty to overshoot pathway characteristics in the near- and long-term? How do different overshoot magnitudes and durations affect adaptation requirements, residual health risks and limits to adaptation? How can health outcome metrics be better integrated into scenario design, model evaluation and risk framing for overshoot pathways?

To be effective and efficient, adaptation planning needs to incorporate the possibility of an overshoot, and what that could mean for adaptation limits and resulting losses and damages for society and nature. This session will explore key questions such as how prospects of potential long-term impact reversal matter for adaptation needs and decision making, and the extent to which exceeding limits to adaptation translates into economic and non-economic loss and damages. We welcome contributions exploring how climate overshoot might lock societies into trajectories that they cannot simply reverse when temperature declines, including loss of ecosystems, resettled populations, abandoned infrastructure, loss of traditional livelihoods and cultural practices, and early signals of these dynamics in markets, institutions, and behaviours, among others. We also call for a focus  on responses to loss and damage at various scales, including the policy contexts and institutional arrangements, and discussing the role of transformational adaptation.

Overshoot pathways raise critical questions about how governance and policy regimes shape who bears the risks and who controls the responses. Emerging national and international strategies increasingly rely on carbon dioxide removal (CDR) to return temperatures below agreed targets, yet the design of these strategies— including how CDR is embedded in Nationally Determined Contributions (NDCs) and Long-Term Low-Emission Development Strategies (LT-LEDS) under the UNFCCC—has profound implications for equity, accountability and credibility of such strategies. This session examines how different governance arrangements for overshoot pathways and CDR allocation influence the distribution of mitigation effort, residual climate risks and co‑impacts across countries, communities and generations. It invites analyses of how overshoot-compatible pathways are being institutionalized in policy and planning, how responsibilities for deploying and financing CDR are framed, and how these choices interact with broader development, energy and land-use priorities. We particularly welcome contributions that: critically assess the role of CDR in NDCs and LT‑LEDS; explore governance options to constrain overshoot magnitudes and durations; and evaluate mechanisms to prevent overshoot pathways from deepening existing inequalities or creating new forms of dependency and lock‑in. Empirical, modelling and conceptual work on governance innovations that center equity in overshoot planning is especially encouraged.