IN THE PAST, when people wondered how to live moral lives, they could look to the saints, or take their questions to church. Today, some of us might instead turn our attention to art and the institutions that house it.

That’s what several dozen artists did, for a related but different reason, last December during the United Nations climate talks in Paris. One afternoon, in a week when crucial policy negotiations were underway, hundreds of environmental activists gathered outside the Louvre to protest the museum’s sponsorship ties to two of the world’s largest oil companies. Among the demonstrators were members of politically minded art collectives like Occupy Museums and Not an Alternative, from the United States, and Liberate Tate, from England.

Carrying open black umbrellas that spelled out the phrase “Fossil Free Culture,” most of them stayed in the plaza around the museum’s glass pyramid, singing and reading position statements. Meanwhile, inside the museum, another action was in progress. Ten performers poured an oily liquid onto the atrium floor and walked barefoot through it, creating a chaotic pattern of footprints before the police moved in.

The Louvre performance was one of a growing number of protests recently directed at large international art institutions, among them the Metropolitan Museum of Art and the Guggenheim Museum in New York. Some museums were urged to stop taking money from ethically dubious corporate or personal sources, including board members who deny that climate change is underway. Others were called out for condoning, if not actively supporting, inhumane labor practices, like those imposed on migrant workers building new Guggenheim and Louvre franchises in Abu Dhabi.