Solidarity within bioethics is increasingly being recognized as an important means of improving health for all. Its contribution seems particularly relevant when there are injustices or inequalities in health and different individuals or groups are disadvantaged. But the current context of ecological collapse, characterized mainly by a loss of biodiversity and ecosystem decline, affects global health in a different way to other factors. This scenario creates new challenges, risks and problems that require new insights from a bioethical perspective. I, therefore, (...) propose an argument in favor of ecological solidarity. The aim of this article is to re-define this concept, outlining which causes should incite action through ecological solidarity and who should be the main recipient of it. To this end, I discuss what the background for practicing ecological solidarity might be: an intrinsically altruistic motivation to attempt to be a better person or a forced response to a political obligation. Finally, by way of example, I argue for rewilding as an effective, practical strategy through which ecological solidarity can be applied in the belief that building ecological solidarity supports a number of key interdependencies and ensures ethical care for the health of the planet. (shrink)