Permafrost Thaw Estimate Calculator Formula
Understand the math behind the permafrost thaw estimate calculator. Each variable explained with a worked example.
Formulas Used
Total Carbon in Thaw Zone
carbon_stored = total_carbon_gtPotential Carbon Released
carbon_released = total_carbon_gt * release_fraction_pct / 100CO2 Equivalent Released
co2_released = total_carbon_gt * release_fraction_pct / 100 * 3.67Variables
| Variable | Description | Default |
|---|---|---|
area_km2 | Permafrost Area Thawing(km²) | 1000000 |
thaw_depth_m | Thaw Depth(m) | 3 |
carbon_density_kg_m3 | Soil Carbon Density(kg C/m³) | 25 |
release_fraction_pct | Carbon Release Fraction(%) | 10 |
total_carbon_gt | Derived value= area_km2 * 1000000 * thaw_depth_m * carbon_density_kg_m3 / 1e12 | calculated |
How It Works
Permafrost Carbon and Climate Feedback
Permafrost soils contain vast stores of organic carbon frozen for thousands of years. As temperatures rise, thawing releases this carbon as CO2 and methane.
Formula
Total Carbon (Gt) = Area (km²) x 10^6 x Depth (m) x Carbon Density (kg/m³) / 10^12
Released Carbon = Total Carbon x Release Fraction
CO2 Released = Released Carbon x 3.67 (molecular weight ratio of CO2 to C)
Arctic permafrost holds an estimated 1,500 Gt of carbon, roughly twice the amount currently in the atmosphere.
Worked Example
One million km² of permafrost thaws to 3 m depth with 25 kg C/m³ density and 10% release.
- 01Total carbon = 1,000,000 x 1,000,000 x 3 x 25 / 10^12 = 75 Gt C
- 02Released = 75 x 10% = 7.5 Gt C
- 03As CO2 = 7.5 x 3.67 = 27.5 Gt CO2
Frequently Asked Questions
What is permafrost?
Permafrost is ground that remains frozen (below 0°C) for at least two consecutive years. It underlies about 25% of the Northern Hemisphere land surface.
Is permafrost thaw a tipping point?
It can be. Once thawing begins, the released carbon causes further warming, which causes more thawing. This positive feedback loop is difficult to reverse.
Does permafrost release methane or CO2?
Both. Aerobic decomposition produces CO2, while anaerobic conditions (like waterlogged soils) produce methane, which has a much higher short-term warming effect.
Ready to run the numbers?
Open Permafrost Thaw Estimate Calculator