Blue Carbon Calculator

Enter your coastal wetland area, ecosystem type, and management action to estimate how much carbon your habitat stores or releases. The Blue Carbon Calculator returns total carbon sequestered, CO₂ equivalent, and a breakdown by carbon pool — helping restoration practitioners, land managers, and planners quantify the climate value of mangroves, seagrass, and salt marshes.

Select the primary coastal wetland type for your site.

ha

Total area of the coastal wetland in hectares.

Choose the land management action taking place at this site.

years

Number of years over which to estimate carbon accumulation or loss (1–100 years).

Approximate depth of organic soil at the site.

Estimated canopy or vegetation cover density at the site.

Climate region affects baseline carbon accumulation rates.

Degree of prior human disturbance or degradation at the site.

Results

Total CO₂ Equivalent Sequestered

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Annual Carbon Sequestration

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Soil Organic Carbon Stock

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Biomass Carbon Stock

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Carbon Density

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Sequestration Rate

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Carbon Pool Breakdown (tCO₂e)

Results Table

Frequently Asked Questions

What is blue carbon and why does it matter?

Blue carbon refers to the carbon captured and stored by coastal and marine ecosystems — primarily mangroves, salt marshes, and seagrass meadows. These habitats store carbon at rates up to 10 times higher than terrestrial forests, mostly in their waterlogged soils, making them critically important for climate mitigation.

Which coastal ecosystems are included in this calculator?

This calculator covers four major blue carbon ecosystems: mangrove forests, salt marshes, seagrass meadows, and tidal flats. Each has distinct carbon accumulation rates derived from published scientific literature and varies by region, vegetation cover, and soil depth.

What units does the calculator use for carbon estimates?

Results are expressed in tonnes of CO₂ equivalent (tCO₂e), the standard unit for greenhouse gas accounting. This allows direct comparison with other carbon offset or emission reduction projects and alignment with IPCC reporting frameworks.

How does the management action affect the carbon estimate?

Management action strongly determines whether a site is a carbon sink or source. Restoration and conservation actions increase carbon sequestration, while degradation or conversion (e.g. draining, clearing) can rapidly release centuries of stored soil carbon. The calculator adjusts its multipliers accordingly for each action type.

What timeframe should I use for my project?

The calculator supports timeframes of 1 to 100 years, consistent with international blue carbon accounting standards. For project-level carbon crediting, 25–30 years is common. For long-term conservation planning, 50–100 year timeframes help capture the full sequestration potential of restored habitats.

Why do tropical ecosystems store more carbon than temperate ones?

Tropical mangroves and seagrass beds benefit from year-round warmth and high productivity, supporting faster biomass growth and deeper soil carbon accumulation. Temperate and boreal sites generally have lower annual accumulation rates, though they can still hold significant carbon stocks in deep peat soils.

How accurate are these estimates?

The calculator uses empirical carbon accumulation rates and stock values drawn from peer-reviewed literature and IPCC wetlands guidance. Estimates are indicative and intended for planning, policy, and scoping purposes. Site-specific field measurements are recommended for formal carbon crediting or permitting applications.

Can I use these results for carbon offset or credit programmes?

These results provide a useful first estimate for feasibility assessment, but verified carbon credits require site surveys, baseline assessments, and third-party validation under recognised standards such as Verra's Verified Carbon Standard (VCS) or the Plan Vivo Standard. Use this tool as an initial scoping aid.

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