What Is the Environmental Impact of Death?

July 9th, 2025

The environmental impact of death care and funerary practices in the U.S. and globally is a growing concern for environmentalists everywhere. Regardless of how a body is disposed of, the process takes a toll on the environment in some way. Although few scientific studies have examined the issue in depth, what we do know for certain is that the disposal of human remains consumes precious and diminishing resources, including energy, space, and natural and man-made materials such as hardwood, steel, concrete, and more. Additionally, the two most common forms of disposition — burial and cremation — both contaminate the environment to some degree. Add to this the environmental impacts of growing and transporting cut flowers, which are staples of U.S. funerals, and the enormous environmental impact of our modern-day death care practices is clear. 

With that being said, it is also clear that the funeral industry in both North America and Europe has taken steps to address these growing concerns by introducing new technologies and new ways of disposing of the dead. Alkaline hydrolysis (sometimes called “green cremation”) has been approved for the disposal of human remains in 28 states across the U.S. and four Canadian provinces and one territory. And while its environmental impact is not negligible, it uses far less energy than cremation and has a much lower carbon footprint, according to the Cremation Association of North America. Unlike burial, it does not require any land use, nor do embalming chemicals remain in the fluid byproduct after the process is complete. 

The Environmental Impact of Conventional Burial

Since the early part of the 20th century, burial practices in the United States have become more and more elaborate. Plain soft-wood coffins, which biodegrade easily, have been replaced by caskets made of hardwood and steel, and grave liners and vaults made of concrete or reinforced concrete have become the norm. Embalming, a practice that uses numerous chemicals, including formaldehyde, phenol, methanol, and glycerin, has also become commonplace. 

The environmental impact of these modern burial practices is significant. According to the latest information from the Green Burial Council, U.S. cemeteries put the following materials  in the ground each year:

• 4.3 million gallons of embalming fluid 
• 20 million board feet of hardwoods (mostly tropical) 
• 64,500 tons of steel (caskets)
• 1,636,000 tons of reinforced concrete (vaults)
• 17,000 tons of copper and bronze
  

Additionally, thousands of tons of granite and marble are transported from all corners of the globe to make headstones for cemeteries in Canada and the U.S. 

Each of these items comes with an environmental cost. Embalming fluid, lacquer, and heavy metals used in caskets can leach into the soil around gravesites and contaminate groundwater. And while concrete itself doesn’t harm the environment, the environmental cost of making concrete is very high. Further, harvesting the tropical woods used in caskets is contributing to deforestation across the globe and, in turn, climate change.  According to one source, the U.S. buries the equivalent of 4 million acres of tropical rainforest in cemeteries each year. 

Additionally, cemeteries take up an enormous amount of space  — space which, in many urban areas, is needed for housing, office space, roads and parks. In many parts of the world, including some metropolitan areas of the U.S., urban planners are searching for novel options to accommodate the dead. In parts of Australia, for example, burial plots are routinely reused after a number of years, with “fresh” bodies placed on top of the old. And in China, millions of interred bodies have been relocated from urban sites to the remote countryside over the past few decades to make room for further development. 

Further, the maintenance required in most large U.S. cemeteries comes at a steep environmental cost. Sweeping lawns and landscaped grounds requires regular mowing and trimming, and the gasoline-powered machinery used to perform these tasks consumes fossil fuels and emits the same kind of pollutants as gasoline-powered cars. Similarly, the fertilizers and pesticides used to keep cemetery grounds beautiful can contaminate the surrounding soil and groundwater and, eventually, plant and animal life.

For all of these reasons, conventional burial as it is practiced in the U.S. is almost certainly the most resource-intensive form of final disposition available today. 

The Environmental Impact of Cremation

Cremation has become a very popular form of final disposition in the United States. In the 15 years between 2000 and 2015, the rate of cremation nearly doubled, from 26.2 % to 48.6 %. And according to the National Funeral Directors Association, that number was projected to reach 57.5% in 2021 and nearly 75% by 2030. That’s about 1,800,000 cremations per year in the United States alone. 

This may be good news in terms of lessening the footprint of modern burials. However, when one considers the environmental impact of cremation, it may actually be cause for concern. According to a 2011 report from NBC News, cremating a single corpse takes 2 to 3 hours at a temperature of about 1,800 degrees Fahrenheit. That’s enough to release 573 pounds of carbon dioxide into the atmosphere. Given current death and cremation rates in the United States, that could result in more than 752 million pounds of carbon dioxide being released into the atmosphere each year. And if the cremation rate continues to rise as expected, that number could mushroom into over a billion pounds of carbon dioxide emissions annually over the next 15 years. 

With that being said, it’s worth noting that this is a minuscule number given the total greenhouse gas emissions generated annually by the United States (15.1 trillion pounds of carbon dioxide equivalents in 2014, according to the EPA). Nonetheless, it points to the fact that carbon emissions from cremations both in the U.S. and globally are cause for some concern. 

Additionally, the process of cremation incinerates not only the body of the person who died, but much of what the body contains. Metal implants such as screws and rods used in orthopedic surgeries are not consumed by the process, and that metal is later retrieved. However, the mercury in dental fillings is vaporized by the high temperatures required for cremation and, unless it’s captured in some way,  released into the atmosphere. This vaporized mercury can linger in the air for up to one year and travel great distances until it slowly oxidizes and is deposited on the ground below. Insofar as mercury is a highly toxic substance capable of damaging the central nervous system and kidneys, especially in a developing fetus, these mercury emissions are also an environmental concern. 

The Environmental Impact of “Green” or Natural Burial

Natural burial, often referred to as “green” burial, is a burial without many of the trappings of a conventional North American burial. Specifically, natural burial grounds do not accept bodies embalmed with toxic chemicals (some “natural embalming products are allowed) and prohibit the use of concrete grave liners or vaults. They also require that bodies be interred in a biodegradable container at a depth of 3.5 feet (in most states) where the population of active “decomposers” such as fungi, bacteria, and — importantly — oxygen is optimal. All of these requirements act to facilitate more rapid decomposition of the body in the top layers of soil, which in turn has a positive impact on the surrounding trees, shrubs, and plants. 

With that being said, there are three levels of green burial grounds recognized by the Green Burial Council in the U.S., and each type has its own criteria that impact how environmentally friendly it is. 

• A hybrid cemetery is a traditional cemetery with an area set aside for natural burial. This area must accept unembalmed bodies and allow burial without a concrete vault or liner. The cemetery must also allow bodies in this area to be buried in a biodegradable container or shroud. In some cases, hybrid cemeteries allow headstones, and the grounds may be maintained using fertilizers, pesticides, and/or gasoline-powered equipment. These practices are prohibited in a natural burial ground. 
  

• A natural burial ground is a cemetery that adheres to all of the standards associated with a green burial, including a prohibition against concrete vaults and grave liners and embalming with toxic chemicals. Additionally, GBC-certified natural burial grounds are required to perform environmental impact assessments on a regular basis to determine the ecological health of the surrounding environment, including the state of the soil and native plants. They also must maintain a “naturalistic” appearance based on [the] use of plants and materials native to the region, and patterns of landscape derived from and compatible with regional ecosystems.” In other words, there are no carefully manicured lawns or rows of headstones. The cemetery doesn’t use heavy machinery to maintain the grounds and avoids the use of pesticides and chemical fertilizers. In most cases, graves are marked naturally with a native plant or naturally occurring rocks or stones. The precise location of the grave is also identified by GPS coordinates. Lastly, natural burial grounds must limit burial density to no greater than 500 burials per acre of land. 
  

• A conservation burial ground is a natural burial ground that not only meets all the criteria set for hybrid and natural burial grounds but also practices land conservation in a way that “conserves, preserves, enhances or restores the historic native or natural habitat or flora of the region.” Conservation burial grounds are also required to operate in conjunction with a government agency or private nonprofit that has a legally binding obligation to perpetually enforce and monitor the easement. Although rare, these conservation grounds are the best option for consumers who wish to make a positive impact on the environment at the time of their death. 
  

Obviously, green burial uses far fewer natural resources than either conventional burial or cremation, and its carbon footprint is smaller by far. Still, some products touted as “sustainable” by green burial advocates carry a rather significant environmental cost. Wicker coffins, for example, are considered environmentally friendly because they are typically made from bamboo or seagrass, which grow back quickly after harvesting. Natural wicker coffins also biodegrade much more quickly than wood. However, the raw materials used in manufacturing wicker coffins are grown in Asia, Africa, South America and Australia and are then shipped to Indonesia, where the bulk of wicker coffins are made. The finished coffins are then transported on a cargo ship to a port in North America for distribution in the United States. In many cases, the actual carbon footprint of the entire process is much higher than that of a casket made of locally grown wood. 

Additionally, natural cemeteries and hybrid cemeteries take up valuable space, which in many urban areas is in short supply. Only conservation burial grounds actively aim to conserve resources by burying bodies in areas where space is not in short supply.

The Environmental Impact of Alkaline Hydrolysis

Alkaline hydrolysis, also known as “resomation” “aquamation” or “green cremation,” is a means of final disposition wherein a body is reduced to bone fragments and a sterile liquid through the use of alkaline chemicals and heat. The process uses a heated solution of water and potassium hydroxide or sodium hydroxide (lye) to accelerate decomposition, leaving behind a liquid known as “effluent” which consists of salts, sugars, proteins and protein chains. Depending on the machinery used and the temperature achieved, alkaline hydrolysis of a human body takes between 3 and 12 hours to complete.

Proponents of alkaline hydrolysis point to its low environmental impact as one of its most attractive traits, and have marketed the technology as “green cremation” to highlight that claim. And the process does, in fact, use less energy than flame-based cremation. According to data from the Cremation Association of North America, alkaline hydrolysis uses about one-tenth of the natural gas and/or electricity as flame-based cremation to achieve the same result. It also produces almost no carbon emissions and virtually no mercury emissions, and the effluent is devoid of contaminants as well. 

Another plus to alkaline hydrolysis is the fact that it allows for the preservation and recycling of implanted devices such as pacemakers, defibrillators and other medical “hardware” such as metal plates and screws. These items are rarely salvaged after flame-based cremation (pacemakers are removed beforehand) because the intense heat damages them extensively, rendering them largely unusable. So much metal can be reclaimed in this way that if alkaline hydrolysis were employed widely across the world, the environmental benefit would almost certainly offset its environmental cost.  

Yet while alkaline hydrolysis seems to have a lower environmental impact than either burial or cremation, it is not entirely without flaws. According to Philip Olsen, an associate professor in the Department of Science, Technology, and Society at Virginia Tech, the process of making lye is extremely energy-intensive, using about 2,500 kWh of electricity per ton of sodium hydroxide produced. (By way of comparison, the average American household uses about 600-1000 kWh per month.) Further, depending on the technology used, the process may emit several hundred pounds of mercury into the atmosphere each year. 

The Environmental Impact of Natural Organic Reduction (Human Composting)

Over the past few years, several states have enacted legislation legalizing the practice of natural organic reduction of human remains. Sometimes referred to as human composting, natural organic reduction is a process in which human remains are placed into a closed, specially designed container with organic materials such as wood chips and straw and allowed to decompose naturally over 4 to 7 weeks. The process uses no chemicals or artificial heat source; decomposition is accomplished by microorganisms that live in the body and the organic materials surrounding it. After decomposition is complete, what remains is about one cubic yard of “soil amendment” or compost. The compost is then “cured” for about a month and then returned to the family or donated as fertilizer. 

Invented and first marketed by Katrina Spade, the founder and CEO of Recompose, natural organic reduction has been shown to remove toxins, medications and disease-causing microorganisms from human remains. Because the heat in the chamber is generated by microbes, it produces no harmful emissions and, according to Recompose, uses one-eighth of the energy consumed by burial or cremation. As of this writing, it appears to have the least environmental impact of all of the currently available means of final disposition, according to a research model created by Troy Hottle, who holds a doctorate in Civil, Environmental, and Sustainable Engineering from Arizona State University. 

In summary, current death care practices in the United States and much of the world pose a serious environmental concern. Air and soil pollution are inherent in both traditional burial and cremation, and even “natural” burial comes at a significant, albeit lower, environmental cost.  Newer technologies, such as natural organic reduction and alkaline hydrolysis, show great promise, but they are available only to a limited number of persons in states that have legalized them at this time. It is our hope that progress towards more sustainable and environmentally friendly options will continue at a rapid pace. 

Sources

“Where in Canada is Aquamation or Alkaline Hydrolysis Legal?” Eirene. https://eirene.ca/articles/canada-aquamation-by-province 

“Why Conventional Burial Harms the Environment”. Milton Fields. https://miltonfieldsgeorgia.com/conventional-burial-harms-environment/ 

“Losing the plot: death is permanent, but your grave isn’t”. The Conversation. https://theconversation.com/losing-the-plot-death-is-permanent-but-your-grave-isnt-33459 

“Stanford historian shows millions of relocated gravesites in China in new, interactive website”. Stanford Report. https://news.stanford.edu/stories/2019/06/documenting-mass-grave-relocation-china 

“Statistics”. National Funeral Directors Association. https://nfda.org/news/statistics 

“When You’re Dying For a Lower Carbon Footprint”. NBC. https://www.nbcnews.com/id/wbna41003238#.WZyaH1WGND9 

“Climate Change Indicators: U.S. Greenhouse Gas Emissions”. EPA. https://www.epa.gov/climate-indicators/climate-change-indicators-us-greenhouse-gas-emissions 

“Q & A: What You Need to Know About Mercury”. Mom’s Clean Air Force. https://www.momscleanairforce.org/mercury-q-and-a/ 

“Mercury and Pregnancy”. March of Dimes. https://www.marchofdimes.org/find-support/topics/pregnancy/mercury-and-pregnancy 

“Our Standards”. Green Burial Council. https://www.greenburialcouncil.org/our_standards.html 

“Philip R. Olson”. Virginia Tech. https://liberalarts.vt.edu/departments-and-schools/department-of-science-technology-and-society/faculty/philip-olson.html 

“Average Household Electricity Consumption – 2025”. Shrink That Footprint. https://shrinkthatfootprint.com/average-household-electricity-consumption/

“Frequently Asked Questions”. Recompose. https://recompose.life/faqs/#human-composting