You don’t need to believe in reincarnation to rejoin the world of the living as a tree.

Isabelle Bolla’s sister passed away from a terminal illness in 2013. Realizing her sister didn’t wish to be buried in a crowded cemetery, Bolla searched online and came upon Bios Urn, a startup company that brings an alternative solution to traditional burial methods. Bios Urn provides customers with a biodegradable urn and a plant seed of choice, which allows family members and friends to fill the urn with their loved one’s ashes and then “plant” it in the ground.

Bolla’s family planted her sister’s Bios Urn in a friend’s backyard in New Mexico, where her sister once lived. Three years later, the tree that emerged is three feet tall.

“It’s really beautiful to know that the tree will be growing every year, in the same way a person would,” Bolla said.

Bolla and her family are just a few of the people who have begun to turn to alternative, more environmentally-friendly methods of burials as a way of embracing a more visceral and poetic meaning to the cycle of life and our eventual return to nature.

These greener ways of approaching death are an important trend. By mid-century, the population of about 80 million Baby Boomers is estimated to dwindle to a mere 16 million, and their deaths could potentially add millions of tons of weight onto our ever-increasing global footprint.

Traditional mortuary methods of burying and cremating the deceased are highly resource-intensive, energy-consuming, and environmentally-destructive. Across the globe, more than 50 million people die each year. In the United States, many are buriedin increasingly limited land space. Caskets and other cemetery structures take up 30 million board-feet — a lumber-specific measurement — of wood. Vaults use 1.6 million tons of concrete and 17,000 tons of steel and copper, and embalming a body requires vast amounts of toxic formaldehyde. Cutting down trees for the caskets and shipping them across the country creates greenhouse gas emissions, as does a body when it begins to decompose.

The term “ashes to ashes, dust to dust” is difficult to achieve in reality, if the deceased are casketed away in coffins and vaults, forced to continuously produce harmful emissions that negatively affect the living. And cremation, though it saves space, still has environmental pitfalls: One cremation produces an average of about 540 pounds of carbon dioxide-equivalent.

Caitlin Doughty, the founder of death-acceptance organization the Order of the Good Death, understands these issues with traditional burials and advocates against “locking up our bodies in a fortress beneath the earth.” She works with funeral directors, medical examiners, artists, and academics to educate the public about death and “natural burials.” By discussing death more openly, people gain the power to choose a more natural burial while they are alive, which allows for “environmental stewardship [to] continue after your death,” Doughty said.

“No one is saying that choosing natural way to dispose of your body is going to solve climate change,” she said. “But if we can’t talk openly about death, how can we talk openly about the death of our planet?”

Items like the Bios Urn and people like Doughty have made some significant impact in the mortuary field in the recent decade. A 2015 Funeral and Memorial Information Council survey found that 64 percent of respondents indicated an interest in green funerals, up from 43 percent in 2010.

Capsula Mundi, another startup company similar to Bios Urn, has 35,000 followers on Facebook, of which a large percentage are between the ages of 25 to 34. Generation X and Millennials display a keen interest in the idea of “green dying” — which makes sense, as they’re also often interested in living in more environmentally-friendly ways, said Anna Citelli and Raoul Bretzel, the founders of Capsula Mundi. This interest in environmentally-friendly burials may inform them when it comes time to bury their parents.

Citelli and Bretzel, like Doughty, hope to change how our society approaches death by providing the opportunity for friends and families to take care of a tree instead of a grave, and to visit loved ones in a forest instead of cemetery. Cremation is not necessary for Capsula Mundi, which eliminates the emissions that are usually produced by the cremation process. The deceased can be buried in fetal positions in biodegradable egg-shaped pods, and, similar to Bios Urn, loved ones can plant trees over the pods. Capsula Mundi’s designers opted to use the symbols of the tree, egg, and the fetal position to help people understand that death is part of the cycle of life, and our physical matter must return back to the Earth.

Death and burial rituals are highly sensitive and complicated, and there’s much more to them than simply putting bodies back into the Earth’s system. But alternative, green, and natural burials do not change the way in which we honor or remember the deceased, and they could breathe new life into the burial process. If the idea of natural burials catches on, survivors could one day honor their loved ones not by visiting a field of tombstones, but by walking through a forest of trees, grown from the ashes of their ancestors.