Planetary health equity (PHE) is the sustainable and equitable enjoyment of the environment and good health. PHE is a concept that recognizes the impact of climate change on social and health inequities. It also recognizes the importance for health equity of considering planetary systems – if we don't have a functioning Earth system, we have social disruption and risks to human survival and good health. Planetary health inequity therefore embodies the common drivers of climate change and health inequity .
PHE is in crisis. Human-made climate change is devastating global populations through hotter temperatures, wildfires, and more severe and frequent storms, flooding, and landslides . A tsunami of health inequities will result from this, as pre-existing inequities in living and working conditions ensure that socially disadvantaged groups and people in low- and middle-income countries are disproportionately impacted by climate change . For example, affluent people can afford to live in insulated buildings with air conditioning and air purifiers, or add flood proofing and extra drainage. Meanwhile, people who are poor, the elderly, people with disabilities, and those who are socially marginalized are the least able to adapt to the changing climate, unable to escape the fires and heat, and live in dwellings and environments that amplify its effects. Some people may leave their communities and perhaps the country - this will exacerbate inequities, with those who have more financial and social capital having more options . All of this climate change-exacerbated social inequity adds to existing inequities in disease burdens and premature mortality.
Despite evidence of these massive challenges and multiple calls to action, why has there been so little effective remedial action? And more importantly, how can we overcome this failure? To answer these questions, this short communication reports on a new research agenda for understanding and advancing PHE. It acknowledges that the global consumptogenic system  of institutions, actors, policies, commercial activities, norms and power relations that incentivizes and rewards the excessive production and consumption of fossil fuel-reliant goods and services that are unhealthy and inequitably valued and distributed lies at the heart of PHE and its investigation.
Important advances have been made in understanding the trajectories of climate change and health inequities. Climate science has shown the planetary boundary stresses and risks to human development . Research in the social and commercial determinants has revealed that poor health and health inequities are strongly influenced by factors beyond the control of individuals, including multisectoral policy and business processes and products [6, 7]. Planetary health research has demonstrated the role of environmental change in the generation of poor health outcomes .
Despite this evidence, 14 years after the recommendations of the World Health Organization (WHO) Commission on the Social Determinants of Health, progress is patchy on health and social equity. Similarly, the Intergovernmental Panel on Climate Change (IPCC) highlights a comprehensive failure to limit climate change . There has been a spectacular policy and governance failure to redress these interconnected issues, and a missed opportunity to reap the co-benefits from action on the common drivers.
Arguably, while the existing research focus in climate change and health is useful, it is insufficient. Often climate, inequities and health issues are examined in isolation or with a focus on the technicalities of the problem rather than understanding the social, policy or political processes that enable or hinder action to improve PHE outcomes. The failure to address climate change and global health inequities clearly suggests that policymakers globally are struggling to develop and implement strategies that advance PHE outcomes.
Fundamentally, a transdisciplinary collaboration in the PHE field is vital, with research seeking to understand how to transform the consumptogenic system towards PHE goals. This requires an understanding of the political economy driving planetary health inequities, with a particular focus on the structures, institutions and paradigms driving major change in policy and business activities, and the impact on PHE. Here we can draw from the social sciences, where theoretical and empirical analyses have identified major threats to the environment and inequality from the dominant market-based economic model that is predicated on forms of growth that consume and deplete natural resources and are highly polluting . Within this literature new economic approaches, including wellbeing economics  and degrowth models , are being considered. Bringing a health equity lens into these types of analyses and debates is essential for PHE. Transforming the consumptogenic system also requires a greater understanding of how to enable inter-sectoral policy and practice focused on mitigating climate change, reducing social inequities and improving health. Policy studies generally, and public health research specifically, offers insights into how the privileging of economic over social and health interests, and power asymmetries between socially- and market-oriented actors makes policy coherence difficult to achieve [6, 13], yet this type of analysis is lacking for PHE. Many of the political, economic, and social factors that make for effective policy and action to address PHE are poorly understood theoretically and empirically, thus making it important to produce evidence that is robust and deliberately eclectic.