The conference will cover a range of relevant topics, arranged in themes.

Highest possible mitigation ambition under overshoot:
The Paris Agreement – in Article 4.3 – requires countries to pursue their “highest possible ambition” in their Nationally Determined Contributions (NDCs), while reflecting principles of equity and fairness. With the world on track to surpass 1.5°C of global warming, the meaning of Paris alignment is increasingly challenged. This session examines how the legal, political, and practical interpretation of highest possible ambition must evolve in the face of overshoot. Bringing together scholars, analysts, and practitioners from diverse disciplines, we invite contributions that explore the implications of Article 4.3 (ever higher ambition of NDCs, reflecting ‘highest possible ambition’) in this new climate reality. How should ambition be assessed in light of historical emissions? What responsibilities in terms of ambition arise for countries that have exceeded their fair share of atmospheric space? How can climate governance adapt to ensure accountability and equity? By reframing ambition through the lens of a 1.5°C overshoot, this session seeks to redefine pathways for meaningful climate action in an era of deepening crisis.

Carbon dioxide Removal: Sustainability constraints and opportunities:
CDR approaches vary broadly from regrowth of natural biomes to engineered extraction and ultimate storage of CO2 from the atmosphere to geologic repositories. 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 invite a wide range of talks focused on how CDR can be scaled sustainably, what are the trade-offs with other mitigation activities, and where are synergies which can accelerate overall net emissions reductions, with a focus on robust strategies that can hedge against key uncertainties such as risk of reversibility or carbon rerelease in multiple phases of climate overshoot. We encourage submissions from topics including enabling conditions and barriers related to e.g., markets, policies, finance, feasibility, verification of removals, and public perceptions.
Earth System responses up to net zero and beyond:
Uncertainties in the Earth System Response under overshoot remain substantial and will determine the potential for global warming reversal. Factors influencing the transient response up to net zero CO2 emissions will determine peak warming and thereby the height of overshoot and respective consequences. Whether and in what way the Earth System response to global net negative emissions is different from the response up to net zero will determine potential, pace and CDR requirements for achieving long-term declining temperatures. In this session, we welcome a wide range of contributions focusing on improving our understanding of the Earth System response up to net zero and beyond. These may include whole Earth System perspectives, but also contributions focusing on specific components such as the carbon cycle. Submissions providing emerging insights from the observational record in the context of overshoot are also welcomed.

Climate impact (ir)reversibility:
Achieving global temperature decline after 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. 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 benefits of long-term global warming reversal compared to stabilisation 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, the temporal interrelations of overshoot pathways with socio-economic development will be explored to better understand the consequences for equity, justice and possible social tipping points

Overshoot legacy and tipping elements:
Overshoots may leave a long-lasting legacy, in particular if irreversible dynamics of Earth System tipping elements were triggered during overshoot. Furthermore, emerging insights suggest that to limit tipping risks on centennial timescales, global warming reversal to levels way below present-day may be required. Yet, the temporal dynamics of potential tipping elements under global peak and decline pathways are so far not well understood. This session welcomes contributions that shed light on dynamics of global tipping elements under 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. The session also welcomes contributions focusing on overshoot legacy beyond tipping elements in relation to global scale outcomes such as sea level rise and ocean dynamics.
Adaptation and adaptation limits under overshoot:
The severity of climate risks under overshoot depends markedly on societal adaptive capacity, as well as the potential transgression of limits to adaptation. The coincidence of overshoot and low adaptive capacity can amplify climate risks. This has profound consequences for the ability to achieve climate-resilient and equitable development outcomes under overshoot, in particular, for the most vulnerable countries, communities and peoples. This session will explore the complexities and challenges of adapting to climate change under overshoot scenarios. We will be taking an explicit pathway perspective on adaptation to explore key questions such as whether prospects of potential long-term impact reversal matter for adaptation needs and decision making. Irreversible impacts under overshoot, especially on sensitive ecosystems, could risk transgressing adaptation limits. To be effective and efficient, adaptation planning needs to incorporate the possibility of an overshoot, and what that could mean for adaptation limits,. The session will also focus on incorporating principles of equity and fairness in adaptation planning that accounts for overshoot.

Loss and damage:
Overshoot impacts will cause lasting loss and damage to societies and ecosystems that will fall disproportionately on the most vulnerable countries, communities and people. The session welcomes contributions that advance our understanding of the consequences of overshoot for exceeding limits to adaptation, and resulting in economic and non-economic loss and damages – including among others health, education, cultural heritage, biodiversity, and ecosystem services. We particularly welcome contributions focusing on disaggregation of the harm felt by marginalized groups and how this intersects with their ability to realise their human rights. 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. Contributions assessing the loss and damage implications of overshoot legacy, as well as potential side effects of large scale carbon dioxide removal are also welcomed.

Legal and justice implications of overshoot:
Climate overshoot highlights the limits of international legal frameworks in addressing climate harms and delivering justice. International legal frameworks emphasize state obligations to prevent overshoot and mitigate its impacts, yet gaps in ambition, accountability and equity persist. Overshoot disproportionately burdens vulnerable communities, and future generations, who will face irreversible loss and damage, escalating costs of addressing runaway temperature rise, and be reliant on unproven technologies like carbon dioxide removal. This session welcomes contributions that explore the legal and justice implications of target breach and consequences for establishing accountability for climate overshoot. These may reflect on the cross-generational rights implications of overshoot, responsibilities for enabling (and paying) for carbon dioxide removal, as well as reparative justice frameworks to address irreversible loss and damage. Contributions that focus on opportunities to address these issues, whether through negotiation or litigation, are particularly welcome.