Global change is an umbrella term that encompasses climate change, biodiversity loss, land-use change, and widespread environmental pollution… All these developments are interrelated, share common causes, and interact in ways that can lead to abrupt and irreversible changes in the environment. Internationally, there is a scientific consensus on the gravity of the situation and the urgency of taking action.

Given the inertia of the atmosphere and the very long lifespan of greenhouse gases, the effects of our current emissions will be borne by future generations, with the most severe scenarios leading to a planet uninhabitable for the human species. These scenarios are not inevitable; the IPCC (Intergovernmental Panel on Climate Change) concluded in 2018 that it would be possible to limit global warming, provided that very strong measures to reduce emissions are implemented immediately. Any delay in taking action drastically reduces the room for maneuver available to future generations. The same applies to biodiversity loss and land-use change.

Another challenge is that some of the necessary actions to reduce emissions, adapt to climate change, and conserve natural areas will exacerbate social health inequalities (just as inaction does).

In terms of public health, we must balance the immediate health benefits of a policy against its impacts on future generations. Air conditioning is a good example: on the one hand, it provides relatively effective protection during heat waves (as long as there is energy to power it). On the other hand, it immediately increases the exposure of people without air conditioning (the outdoor temperature would have been 2°C higher in Paris in 2003 if all buildings had been air-conditioned), while contributing to long-term warming.

The health impacts of climate change were officially recognized in the preamble to the 2015 Paris Agreement and in a 2017 UN special report. Yet the earliest research on this topic dates back to the 1980s. The identified causes of this limited consideration include a focus on individual determinants of health at the expense of environmental and social determinants, a highly economic approach that undervalues the health of future generations, and the difficulty health professionals face in building connections with environmental professionals. In this article, we propose three avenues for progress:

• Better document and communicate about already observable and future impacts, including to audiences that are not typical health stakeholders.

• Develop a truly interdisciplinary approach in the research conducted, reaching out to environmental sciences, as well as the humanities and social sciences, and artists.

• In studies of future impacts, incorporate all scenarios, including the most pessimistic ones that we wish to avoid at all costs (until recently, many studies favored scenarios of low to moderate warming).

• Further study the repercussions of actions to reduce greenhouse gas emissions and conserve nature, in order to highlight the co-benefits, without glossing over possible negative impacts.

• Allocate sufficient resources to these issues.

The InVS* has been working on climate change since 2009 to identify health risks that may be influenced by climate, document impacts that are already observable, and promote preventive measures (adaptation). This work has thus contributed to the development of the national adaptation strategy and national adaptation plans. Since 2015, the agency has been increasingly called upon to provide information on the impacts of climate change, particularly in the context of regional climate, air, and energy plans (SRCAE) and regional adaptation plans. Currently, a key challenge is to develop impact indicators to feed into national and regional observatories on the effects of climate change, which serve as the foundation for implementing adaptation policies. In parallel with these advocacy efforts, the agency has participated in several international studies on the future impacts of temperature and air pollution on health.

A comprehensive strategy is being implemented within Santé publique France: it relies on the thematic support committee** established in 2018 and on a GEPP (Professional Practice Exchange Group) on “Climate Change” currently being developed, involving all departments of Santé publique France to integrate this essential dimension into all of the Agency’s programs.