Wendy Broadgate

Humans are now operating well outside the planetary conditions under which social and economic development has been possible. A precondition for securing equitable access to this prosperity is to safeguard the stability of the Earth system. The situation is urgent—we need a swift and profound shift in direction—a collective transformation. In response, the Earth Commission has developed a science‐based framework that integrates biophysical limits with justice considerations, aiming to enable human wellbeing for all. The Earth Commission's first assessment showed that multiple safe and just Earth system boundaries have already been transgressed, threatening the resilience of the planet and the well‐being of billions. This paper outlines the vision and scientific strategy for the Earth Commission's second phase (2024–2027), which focuses on advancing this framework and translating it into actionable budgets and exploring transformation pathways toward a safe and just future. Key components include expanding the safe and just boundary assessment to currently under‐assessed Earth system processes (e.g., novel entities and ocean change), integrating justice more deeply into the framework, modeling interactions between boundaries and tipping points, and developing practical approaches to cross‐scale translation and transformation. Special attention is given to the structural inequalities and power dynamics that shape both environmental degradation and our capacity to act. Through coordinated research, interdisciplinary collaboration, and stakeholder engagement, the Earth Commission seeks to provide knowledge to guide collective efforts toward transforming to a safe and just space for both people and the planet.

Humans are now operating well outside the planetary conditions that enabled stable and equitable development. The situation is urgent — we need a swift and profound shift in direction — a collective transformation. In response, the Earth Commission has developed a science-based framework that integrates biophysical limits with justice considerations, aiming to secure a liveable and dignified future for all. The Earth Commission’s first assessment showed that multiple safe and just Earth system boundaries have already been transgressed, threatening the resilience of the planet and the well-being of billions. This paper outlines the vision and scientific strategy for the Earth Commission’s second phase (2024–2027), which focuses on advancing this framework and translating it into actionable budgets and exploring transformation pathways to a safe and just space. Key components include expanding the safe and just boundary assessment to currently under-assessed Earth system processes (e.g., novel entities and ocean change), integrating justice more deeply into the framework, modelling interactions between boundaries and tipping points, and developing practical approaches to cross-scale translation and transformation. Special attention is given to the structural inequalities and power dynamics that shape both environmental degradation and our capacity to act. Through coordinated research, interdisciplinary collaboration, and stakeholder engagement, the Earth Commission seeks to provide knowledge to guide collective efforts toward transforming to a safe and just space for both people and the planet.

Non-technical summary: We identify a set of essential recent advances in climate change research with high policy relevance, across natural and social sciences: (1) looming inevitability and implications of overshooting the 1.5°C warming limit, (2) urgent need for a rapid and managed fossil fuel phase-out, (3) challenges for scaling carbon dioxide removal, (4) uncertainties regarding the future contribution of natural carbon sinks, (5) intertwinedness of the crises of biodiversity loss and climate change, (6) compound events, (7) mountain glacier loss, (8) human immobility in the face of climate risks, (9) adaptation justice, and (10) just transitions in food systems. Technical summary: The Intergovernmental Panel on Climate Change Assessment Reports provides the scientific foundation for international climate negotiations and constitutes an unmatched resource for researchers. However, the assessment cycles take multiple years. As a contribution to cross- and interdisciplinary understanding of climate change across diverse research communities, we have streamlined an annual process to identify and synthesize significant research advances. We collected input from experts on various fields using an online questionnaire and prioritized a set of 10 key research insights with high policy relevance. This year, we focus on: (1) the looming overshoot of the 1.5°C warming limit, (2) the urgency of fossil fuel phase-out, (3) challenges to scale-up carbon dioxide removal, (4) uncertainties regarding future natural carbon sinks, (5) the need for joint governance of biodiversity loss and climate change, (6) advances in understanding compound events, (7) accelerated mountain glacier loss, (8) human immobility amidst climate risks, (9) adaptation justice, and (10) just transitions in food systems. We present a succinct account of these insights, reflect on their policy implications, and offer an integrated set of policy-relevant messages. This science synthesis and science communication effort is also the basis for a policy report contributing to elevate climate science every year in time for the United Nations Climate Change Conference. Social media summary: We highlight recent and policy-relevant advances in climate change research – with input from more than 200 experts.

The stability and resilience of the Earth system and human well-being are inseparably linked^1–3, yet their interdependencies are generally under-recognized; consequently, they are often treated independently^4,5. Here, we use modelling and literature assessment to quantify safe and just Earth system boundaries (ESBs) for climate, the biosphere, water and nutrient cycles, and aerosols at global and subglobal scales. We propose ESBs for maintaining the resilience and stability of the Earth system (safe ESBs) and minimizing exposure to significant harm to humans from Earth system change (a necessary but not sufficient condition for justice)⁴. The stricter of the safe or just boundaries sets the integrated safe and just ESB. Our findings show that justice considerations constrain the integrated ESBs more than safety considerations for climate and atmospheric aerosol loading. Seven of eight globally quantified safe and just ESBs and at least two regional safe and just ESBs in over half of global land area are already exceeded. We propose that our assessment provides a quantitative foundation for safeguarding the global commons for all people now and into the future.

Non-technical summary: We summarize what we assess as the past year's most important findings within climate change research: limits to adaptation, vulnerability hotspots, new threats coming from the climate–health nexus, climate (im)mobility and security, sustainable practices for land use and finance, losses and damages, inclusive societal climate decisions and ways to overcome structural barriers to accelerate mitigation and limit global warming to below 2°C.Technical summary: We synthesize 10 topics within climate research where there have been significant advances or emerging scientific consensus since January 2021. The selection of these insights was based on input from an international open call with broad disciplinary scope. Findings concern: (1) new aspects of soft and hard limits to adaptation; (2) the emergence of regional vulnerability hotspots from climate impacts and human vulnerability; (3) new threats on the climate–health horizon – some involving plants and animals; (4) climate (im)mobility and the need for anticipatory action; (5) security and climate; (6) sustainable land management as a prerequisite to land-based solutions; (7) sustainable finance practices in the private sector and the need for political guidance; (8) the urgent planetary imperative for addressing losses and damages; (9) inclusive societal choices for climate-resilient development and (10) how to overcome barriers to accelerate mitigation and limit global warming to below 2°C.Social media summary: Science has evidence on barriers to mitigation and how to overcome them to avoid limits to adaptation across multiple fields.

The first symposium on “The Ocean in a High-CO2 World” in 2004 proved to be a landmark event in our understanding of the seriousness of ocean acidification, as reported in Oceanography (Cicerone et al., 2004). The scientific community reunited in 2008 for a second symposium on “The Ocean in a High-CO2 World.” During the four years between the two symposia, more scientific papers were published on the topic of ocean acidification than during the preceding 55 years. Ocean acidification is now widely cited in the press and is familiar to many nonscientists. Participants at the 2008 symposium identified new research priorities and stressed the importance of improving international coordination to facilitate agreements on protocols, methods, and data reporting in order to optimize limited resources by greater sharing of materials, facilities, expertise, and data. Despite major uncertainties, the research community must find ways to scale up understanding of individual organisms’ responses to provide meaningful predictions of ocean acidification’s effects on food webs, fisheries, marine ecosystems, coastal erosion, and tourism. Easy-to-understand information, such as simple indicators of change and of thresholds beyond which marine ecosystems will not recover, is also needed for management and policymaking