Desmond Tutu opted for a plain pine coffin and aquamation, the green alternative to cremation

Family members gathered at a private service at St. George's Cathedral on Sunday to say their goodbyes to Desmond Tutu, the anti-apartheid leader and Anglican archbishop emeritus, who died on the 26th December at age 90. The Nobel Peace Prize laureate had requested a humble sendoff in a pine coffin without extravagant spending on the services. Tutu, as a champion of the environment, had asked that his body not be cremated by flame and that it instead undergo aquamation, an eco-friendly alternative to traditional cremation, reports The Washington Post.

The scientific name for this water-based process is "alkaline hydrolysis". Aquamation is part of a growing "green burial" movement that avoids fossil fuels and non-biodegradable materials for the purpose of decomposition. According to Bio-Response Solutions—a US company that specializes in aquamation—in this process, a "combination of gentle water flow, temperature, and alkalinity is used to accelerate the breakdown of organic materials". The company also estimates that the technology "uses 90% less energy than flame cremation and does not emit any harmful greenhouse gases."

In a 2014 paper, Philip Olson—a technology ethicist at Virginia Tech—explained that in aquamation, a machine uses "a heated (sometimes pressurized) solution of water and strong alkali to dissolve tissues, yielding an effluent that can be disposed of through municipal sewer systems, and brittle bone matter that can be dried, crushed and returned to the decedent's family." The process is said to take three to four hours at a temperature of around 300 degrees Fahrenheit, but can be longer if conducted at lower temperatures are used, Olson explained. By comparison, traditional cremation uses temperatures as high as 1,600 degrees Fahrenheit and takes approximately two hours.

Aquamation was first adopted in the United States in the 1990s by researchers looking for an inexpensive and safe way to discard the remains of animals used in experiments. According to Olson, around the same time, scientists in Japan and Scotland began studying its use for disposing of the bodies of animals affected by illnesses such as mad cow diseases. The practice gained popularity among veterinarians in the United States by the early 2000s and the following decade saw aquamation being marketed to funeral homes as the technologies improved and interest widened.

Aside from being a staunch defender of human rights, Tutu—who was affectionately known as "the Arch"—was also a champion of the environment and used his voice to amplify the need to act to tackle the climate crisis. In a 2007 piece titled "This Fatal Complacency" for the Guardian, he addressed the worrying impact that climate change was having in the Global South and on poor communities, while much of North America and Europe was yet to experience extreme weather conditions caused by the climate emergency at this time. "Every child will remember the story of the three little pigs and the big bad wolf," he wrote.

"In the world we live in, the bad wolf of climate change has already ransacked the straw house and the house made of sticks, and the inhabitants of both are knocking on the door of the brick house where the people of the developed world live. Our friends there should think about this the next time they reach for the thermostat switch. They should realize that while the problems of the Mozambican farmer might seem far away, it may not be long before their troubles wash up on their shores," Tutu added. He also advocated for boycotts of oil and fossil fuel-producing firms, called for greater investment in clean energy and low-carbon products and sought to amplify the voices of young climate activists.