What does a ton of carbon cost to remediate or eliminate?

v1.3 · July 9, 2026

Each measure below deals with a ton of CO₂ at some price. Most keep it from being emitted. Direct air capture takes it back out of the air afterward. Enter your own numbers to see what a ton costs. Defaults describe a cold-climate house and are meant to be changed.

This page prices carbon and nothing else. For most households the better arguments are comfort and having more than one fuel to choose from. Neither appears anywhere below.

Assumptions

Measures

Measure	Cost low	Cost high	Key input	Life	Gas cut	$ per tonvs. gas-heated house	$ per tonafter the heat pump

Reset to defaults

Cost per ton of CO₂ avoided

Is there a substitute?

Cost per ton says what a ton costs from a given measure. It does not say whether another measure could have delivered the same ton for less. That is a separate question, and it decides which measures are load-bearing.

Emission factors

• Natural gas at 5.31 kg CO₂ per therm and gasoline at 8.89 kg per gallon, both from EPA. Combustion only.
• Electricity is credited at the average grid emissions factor, declining at the rate set above. Each measure sees the average factor over its own life, so a 40-year measure is credited against a cleaner grid than a 12-year one.
• EPA guidance holds that a marginal emissions factor, which is usually higher than the average, better describes what efficiency and renewables actually displace. Using it would improve rooftop solar and worsen the heat pump and the EV. The average is used here for all three rather than picking.
• Transmission and distribution losses, roughly 5% nationally, are not added, so electricity emissions are slightly understated. Upstream methane leakage from gas production and distribution is not counted either, so gas emissions are also understated. The two partly offset.

How each measure is credited

• Heat pump and EV results are net: fuel avoided minus the emissions of the electricity that replaces it.
• The two AC-to-heat-pump rows are the same physical conversion at two prices. Both are incremental costs, which assumes the air conditioner was being replaced anyway. If it wasn't, the relevant cost is the whole system, not the delta.
• Geothermal is priced only against the air-source heat pump, since its cost here is the difference between the two systems. It is credited with the gas the heat pump was still burning, plus the higher COP.
• Rooftop solar is priced per watt installed. Everything else in the house is priced as a total.
• Onshore wind and utility-scale solar are priced differently from everything else: their cost per ton is the difference between their levelized cost of energy and that of the new gas plant they compete against, divided by the roughly 0.40 tons of CO₂ a megawatt-hour of gas generation emits. Ranges are Lazard's 2025 unsubsidized figures. When a renewable is cheaper than the gas plant, the cost per ton is negative, which means the ton was avoided at a profit.
• Gas cut is the share of the home's original heating gas a measure removes on its own, measured against a gas-heated house.

What is not counted

• Shell measures are credited with fuel savings only. Comfort, durability, cooling savings, and the smaller equipment a lower load allows are real and appear nowhere on this page.
• Shell work is treated as permanent and defaults to 50 years, a defensible remaining life for a house. But a shell measure only avoids gas for as long as the house burns gas. Crediting it with 50 years of avoided gas assumes 50 more years of gas heating. Shorten the life to see what happens if the house electrifies sooner.
• In a house that already has a heat pump, shell work also reduces heat pump electricity. That benefit is not credited, so the second column understates shell measures.
• Nothing here values reliability, resilience, air quality, or health.

Known limits

• Results are undiscounted. Costs are paid up front and tons accrue over time, so applying a discount rate would raise every dollars-per-ton figure on this page, and would raise the longest-lived measures the most.
• Two baselines are shown because the answer depends on what the house would have gotten otherwise. Against a gas-heated house, a shell measure gets credit for all the gas it saves. Against a house that already has the heat pump, it gets credit only for the gas the heat pump was still going to burn.
• Every measure except direct air capture is priced on emissions avoided. Direct air capture is priced on emissions removed after the fact. They are not interchangeable, and some emissions have no avoidance option at all.
• Every default on this page was chosen by Nate Adams, drawn from two decades of project data, job costs, and one 1835 general store he decided not to retrofit. They are starting points, not findings. Change them.
• "Tons" means tons of CO₂, not tons of equipment capacity.

This is unfunded. I built it out of curiosity. If you find something that doesn't make sense, let me know at [email protected]. (Nobody is paying me to maintain it, so go easy.)