Dilemmas that clinicians face in the coronavirus pandemic–who gets the ventilator, the 80-year-old grandmother or the 20-year-old student?–are the bread and butter of mainstream bioethics. In medical school, my classmates and I memorized the four principles (beneficence, nonmaleficence, justice, and autonomy), which we were told would help us make hard clinical decisions in ethically ambiguous terrain. But Covid-19 shows that medical ethics means much more than what generally falls under bioethics. Medical ethics is deeply political, and to act ethically in medicine means engaging the larger context in which it operates.

Are we ethically obliged to eat less meat? Bioethicists consider that question, and their role in addressing it.

What does it mean to live well on a warming planet? And as the climate changes, how might health care, education, and other sectors support, or obstruct, our ability to respond? The answers to these profound, and profoundly bioethical, questions will critically influence human well-being in this century and beyond. A group of scientists, educators, and bioethicists convened at The Hastings Center recently to consider these questions and begin an interdisciplinary conversation on how bioethics might address the challenges posed by climate change.

After years of fluctuating and troubled efforts, the nations of the world in December of 2015 came to the remarkable agreement to work together to reduce global warming. On June...