HIMALAYAS — Rural villagers in the Himalayas coined the term tree-hugger in 1973 when they launched the Chipko movement to protest the commercial logging of hornbeam trees. Chipko means "to hug" or "to stick to something" in Hindi, and the word has come to describe environmentalists and advocates for the preservation of woodlands.

Before the first protest, the Indian government owned the rights to the forest and had allowed an international company to use the trees to make tennis racquets. Hornbeam trees were a cornerstone of the local economy and prevented landslides and floods, leading locals to ensure sustainable harvesting.

Inspired by Gandhian nonviolent social action, villagers threatened to hug the trees to protect them. Around 300 men, women and children threatened to take action, prompting the government to back off, according to environmental historian Ramachandra Guha. Photographs of women hugging trees were staged after the fact, he said.

"It was an assertion of their economic and social rights," Guha said. "We need these trees and these forests for our survival."

Women took center stage in the Chipko movement as its main activists. From 1973 to around 1980, dozens of peaceful rallies were held against clear-felling in the Himalayas. The government responded by banning the cutting down of trees in the area.

Guha compared the Chipko movement to Rachel Carson's Silent Spring, saying both invoked social justice and environmental sustainability. He wrote the book Speaking with Nature: The Origins of Indian Environmentalism.

The Chipko movement is connected to the earlier Bishnoi people in northwest India, according to Vandana Shiva. In 1730, members of the Bishnoi faith in Khejarli died to protect the sacred Khejri trees, a flowering tree native to Western Asia and India. Amrita Devi and her young daughters offered their heads in exchange for saving the Khejri trees, and when the story spread, 363 people also sacrificed their lives for the trees. The king of Jodhpur issued a royal decree making the cutting of the Khejri trees illegal, a precedent that still exists today. Guha said there is no historical evidence to back the Bishnoi legend, calling it a "popular myth."

In 2013, the government of India designated Sept. 11 as National Forest Martyrs Day. In the United States, the term tree-hugger appeared in writing as early as the 1960s but was not used more widely in American politics until the 1990s.