Options

Natural and conservation burial return an unembalmed body directly to the earth in a biodegradable container, with no vault, no metal, and no chemical preservation. It is consistently among the lowest-impact options measured, and conservation burial has the added feature of using cemetery revenue to permanently protect the underlying land^[reference]. "Green" is not automatic, though — the actual footprint depends heavily on how the cemetery is run.

The process

The body is not embalmed. It is placed in a biodegradable container — a shroud, a wicker or wood casket, sometimes just a cotton wrap — and buried at a depth that supports aerobic decomposition (typically three to four feet, shallower than a conventional grave). No concrete or metal vault is installed. No permanent headstone is required; markers are usually flat native stone, a GPS coordinate, or a planted tree. Decomposition proceeds naturally, and the body's nutrients return to the soil column over months to years.

Two variants matter here. A natural burial ground simply omits the vault, embalming, and manicured landscaping — it is a lower-input version of a normal cemetery. A conservation burial ground goes further: the site is held under a legally binding conservation easement, meaning burial fees directly fund the permanent protection and ecological restoration of the land itself^[reference].

Environmental scorecard

Compared to flame cremation: roughly a quarter to a half of the carbon depending on cemetery operations. No manufactured casket. No cremation fuel. No embalming chemicals.

Honest caveat

"Natural" is a label the operator applies to themselves. A cemetery that calls itself green but still mows weekly, irrigates, and sells vaults is not comparable to a certified conservation ground. Ask what the site is certified as, and by whom. On the groundwater question — the materials buried, not the body, are the main source of cemetery leachate: see Q&A: What actually leaches out of a buried casket?

Legal status

Natural burial is legal in all 50 US states — no state explicitly prohibits it^[reference]. Embalming is not required by law in any state; a small number require it only for specific circumstances (transport across state lines, extended delay before burial, or certain communicable-disease cases). The real friction is not state law — it is individual cemetery policy (many private cemeteries still require a vault) and county zoning for private-land or family-cemetery burial, which varies dramatically by jurisdiction^[reference]. If you want a true natural or conservation burial, the practical question is not "is it legal here?" but "does a certified natural or conservation burial ground exist within a reasonable distance?"

Human composting, formally called Natural Organic Reduction (NOR), places the body in a sealed vessel with wood chips, alfalfa and straw, where controlled airflow, heat and microbial activity reduce it to roughly a cubic yard of usable soil in four to seven weeks. It is very low-carbon relative to conventional burial or cremation and produces a genuine give-back — soil that can be used to restore land^[reference]. It is currently legal in 14 US states, with more states advancing legislation^[reference].

The process

The body, unembalmed, is placed in a vessel — Recompose uses a hexagonal steel cylinder about eight feet long — along with a specific ratio of wood chips, alfalfa and straw that provides the carbon and nitrogen microbes need. Airflow is actively managed to keep the process aerobic (oxygen-rich), which is what distinguishes it from a landfill or anaerobic pile. Temperatures inside the vessel rise to around 55 °C (131 °F) for several days, meeting the same pathogen-reduction thresholds used in agricultural composting. After roughly 30 to 45 days, remaining bone fragments are mechanically reduced and re-added, and the resulting soil cures for another few weeks before it is returned to family or donated to a conservation project.

Environmental scorecard

Recompose estimates roughly one metric ton of CO₂ avoided per person versus conventional burial or cremation^[reference] — read the caveat below before quoting that number.

Honest caveat

Composting is not emission-free. Even well-aerated composting releases some methane (CH₄) and nitrous oxide (N₂O), both far stronger greenhouse gases than CO₂ (roughly 28× and 265× on a 100-year basis, per IPCC AR5)^[reference]. And the widely-quoted "saves one metric ton of CO₂" figure is framed by its originator as a comparison against conventional burial or cremation, not an absolute — a distinction Green Burial Council-affiliated critics have made publicly^[reference]. On soil safety, testing has shown the finished material meets or exceeds EPA compost standards for heavy metals — see Q&A: Can the soil from human composting be used to grow food?

Legal status

Legal in 14 US states as of 2026: Washington (first, 2019), Colorado, Oregon, Vermont, California, New York, Nevada, Arizona, Maryland, Delaware, Maine, Georgia, Minnesota, and New Jersey^[reference]. Effective dates matter — California's law was signed in 2022 but does not take effect until 2027, and New Jersey's regulations are still being drafted^[reference]. Illinois and Utah have active legislation moving through their chambers in 2026. If you live in a state where NOR is not legal, remains can be shipped to a licensed provider (Recompose in WA, Earth Funeral in OR, Return Home in WA, Herland Forest in WA, and others) — this is legal, common, and adds transport cost and carbon on the order of a few hundred kilograms depending on distance.

Aquamation — formally alkaline hydrolysis or resomation — dissolves soft tissue in a heated, pressurised solution of water and potassium hydroxide over three to sixteen hours, leaving only sterile bone that is dried and returned to family as a white powder. On energy and carbon it is consistently the lowest of the technical (non-burial) processes, using a small fraction of the energy of flame cremation and emitting no mercury^[reference]. It is currently legal in 26 US states as of CANA's March 2026 tracker, with more advancing^[reference].

The process

The body is placed in a stainless-steel pressure vessel, which is then filled with a solution that is approximately 95% water and 5% potassium hydroxide (KOH) — the same base found in soap-making. The vessel is heated to around 150 °C (302 °F) under pressure, or to lower temperatures (~93 °C) for a longer duration if the operator uses a low-temperature system. Over three to sixteen hours, the alkaline solution hydrolyses the body's soft tissue into a sterile liquid consisting of water, salts, amino acids, peptides and sugars. What remains is the skeleton — softer than after flame cremation because no combustion took place — which is dried and processed into a fine white powder returned to the family. The remaining liquid (the "effluent") is released to the sanitary sewer system after cooling.

One unusual property of the chemistry: the process is aggressive enough to destroy infectious prions (the proteins responsible for Creutzfeldt-Jakob and BSE) and to break down most pharmaceutical residues — outcomes that neither flame cremation nor burial reliably achieve. This is why the USDA and biosecurity facilities adopted alkaline hydrolysis for pathogen-containing carcass disposal well before the funeral industry did. See Q&A: Where does the aquamation liquid go, and is that safe?

Environmental scorecard

Planet Mark reports resomation at ~20 kg CO₂e vs 126 kg for gas cremation — roughly one-sixth^[reference]. Other operators cite ~90% carbon reduction^[reference]. "Roughly a tenth" is a defensible, rounded simplification.

Honest caveat

The peer-reviewed LCA that gives aquamation its strong energy/carbon numbers explicitly did not fully model the chemical composition of the effluent or its downstream wastewater-treatment impacts, and flagged this as a limitation warranting further study^[reference]. Planet Mark's report notes the same gap^[reference]. So "cleanest technical process" is well-supported on energy and carbon, and less well-studied on water chemistry. Publicly owned wastewater treatment plants routinely accept the effluent, but the LCA jury is still out.

Legal status

Legal in 26 US states as of CANA's March 2026 tracker^[reference], and in five Canadian provinces. Roughly half of US states have authorised it — but legality does not always mean availability: a handful of states have legalised the process without any operating provider yet, so the practical map is smaller than the legal one^[reference]. As with human composting, remains can be transported across state lines to a licensed provider. Momentum is steady; several additional states have bills advancing in 2026.

Natural and conservation burial return an unembalmed body directly to the earth in a biodegradable container, with no vault, no metal, and no chemical preservation. It is consistently among the lowest-impact options measured, and conservation burial has the added feature of using cemetery revenue to permanently protect the underlying land^[reference]. "Green" is not automatic, though — the actual footprint depends heavily on how the cemetery is run.

The process

The body is not embalmed. It is placed in a biodegradable container — a shroud, a wicker or wood casket, sometimes just a cotton wrap — and buried at a depth that supports aerobic decomposition (typically three to four feet, shallower than a conventional grave). No concrete or metal vault is installed. No permanent headstone is required; markers are usually flat native stone, a GPS coordinate, or a planted tree. Decomposition proceeds naturally, and the body's nutrients return to the soil column over months to years.

Two variants matter here. A natural burial ground simply omits the vault, embalming, and manicured landscaping — it is a lower-input version of a normal cemetery. A conservation burial ground goes further: the site is held under a legally binding conservation easement, meaning burial fees directly fund the permanent protection and ecological restoration of the land itself^[reference].

Environmental scorecard

Compared to flame cremation: roughly a quarter to a half of the carbon depending on cemetery operations. No manufactured casket. No cremation fuel. No embalming chemicals.

Honest caveat

"Natural" is a label the operator applies to themselves. A cemetery that calls itself green but still mows weekly, irrigates, and sells vaults is not comparable to a certified conservation ground. Ask what the site is certified as, and by whom. On the groundwater question — the materials buried, not the body, are the main source of cemetery leachate: see Q&A: What actually leaches out of a buried casket?

Legal status

Natural burial is legal in all 50 US states — no state explicitly prohibits it^[reference]. Embalming is not required by law in any state; a small number require it only for specific circumstances (transport across state lines, extended delay before burial, or certain communicable-disease cases). The real friction is not state law — it is individual cemetery policy (many private cemeteries still require a vault) and county zoning for private-land or family-cemetery burial, which varies dramatically by jurisdiction^[reference]. If you want a true natural or conservation burial, the practical question is not "is it legal here?" but "does a certified natural or conservation burial ground exist within a reasonable distance?"

Flame cremation reduces the body to bone fragments and ash inside a natural-gas-fired retort operating at 760–1,150 °C (1,400–2,100 °F) for two to three hours. It is the most common alternative to burial in the US, and its carbon footprint is mid-range: peer-reviewed and industry estimates run roughly 80 to 126 kg CO₂-equivalent per cremation depending on the local energy grid, retort technology, and system boundaries^[reference]. It also emits more than CO₂ — mercury, dioxins, and particulate matter are all on the stack.

The process

The body, in a combustible container (usually a cardboard or minimum-material wood casket), is placed into a refractory-lined retort. A primary natural-gas burner brings the chamber to combustion temperature; a secondary chamber then further oxidises the flue gases to reduce particulates and odour before they leave the stack. After about ninety minutes to three hours, what remains is bone — soft and calcined — which cools, is inspected for surgical metal (removed and recycled), and is then reduced in a cremulator to the fine grey particulate returned to families as "ashes." A single cremation typically consumes on the order of 28 cubic metres of natural gas plus supporting electricity for burners, blowers and controls.

Environmental scorecard

Roughly 80–126 kg CO₂e per cremation depending on grid and method^[reference]. Fossil fuel is burned every time. This is the reference number all the other methods are compared to.

Honest caveat

Cremation emits mercury vapour from vaporised dental amalgam, plus dioxins, furans, NOx and fine particulates. Peer-reviewed Canadian data attributes roughly 6% of national mercury emissions and 5% of national dioxin emissions to crematoria^[reference]. UK crematoria have been required to install mercury abatement equipment since the mid-2000s; US regulation is inconsistent by state. Full breakdown in Q&A: What exactly comes out of a crematorium stack?

Legal status

Legal in all 50 US states, with no meaningful legal barrier to access. Most states impose a mandatory waiting period of 24 to 48 hours between death and cremation — Minnesota requires 48 hours, Texas 48, Florida 48, Illinois 24 — to allow time for the medical examiner to release the body and for family authorization to be properly documented^[reference]. A signed cremation authorization form from the legally recognised next of kin (or a pre-death directive from the decedent) is required in every state. Scattering of resulting cremated remains is broadly permitted on private land with the owner's consent, on federal land under agency-specific rules (National Park Service permits are often required), and at sea beyond three nautical miles from shore, reported to the EPA within 30 days^[reference].

A memorial reef mixes cremated remains into a hollow, textured concrete structure — most commonly a "reef ball" — which is then placed on a permitted section of seabed to serve as artificial marine habitat. The concrete is engineered to a near-neutral pH and a rough surface so coral, algae and invertebrates can colonise it^[reference]. It is a give-back of a different kind — habitat creation rather than soil return — but because it requires cremation first, it inherits cremation's carbon footprint.

The process

After flame cremation (or, in some cases, aquamation), the remains are handed to a memorial-reef provider such as Eternal Reefs or Memorial Reefs International. The provider mixes the cremains into a specialised pH-neutral marine concrete and casts them into a hollow, vented, textured dome — a reef ball — typically 2 to 6 feet across and weighing several hundred to several thousand pounds. Families are invited to hand-imprint the wet concrete and place mementos. Once cured, the reef ball is deployed by boat to a permitted artificial-reef site — most are off Florida, Texas, the Carolinas, New Jersey and Maryland — under state and federal (US Army Corps of Engineers) permits. Once on the seabed, the structure is colonised over months and years by algae, invertebrates, corals and fish^[reference].

Environmental scorecard

* Inherits the cremation footprint (~80–126 kg CO₂e^[reference]) plus the embodied carbon of concrete and boat fuel. Give-back is in a different currency: habitat, not soil.

Honest caveat

The ecological benefit of artificial reefs is real but site-dependent — a reef ball dropped in an already-thriving natural reef area does less than one placed on a degraded, sandy or trawl-scarred bottom^[reference]. Rigorous peer-reviewed ecological studies of memorial-reef programs specifically (as opposed to artificial reefs in general) remain limited. Memorial reefs are not in themselves a low-carbon disposition — grade them honestly on both sides.

Legal status

Legal nationally, but more regulated than most people assume. Because a memorial reef ball is an artificial structure placed on the seabed, it is not eligible for authorization under the EPA's general Marine Protection, Research and Sanctuaries Act (MPRSA) permit that covers ordinary burial-at-sea and simple ash scattering^[reference]. Memorial reef providers instead operate under site-specific permits from the US Army Corps of Engineers and state coastal-resource agencies for each permitted artificial-reef site^[reference]. This is why placements are concentrated at a defined set of approved sites — most off Florida, Texas, the Carolinas, New Jersey, Maryland and Virginia. Cremation must occur first (which is legal in all 50 states), and the family works through a licensed provider such as Eternal Reefs or Memorial Reefs International; individuals cannot legally deploy their own memorial reef structure.