How do Carbon Credit Methodologies work?

Carbon Project Methodologies

Baseline, project, and the tonne in between.

Carbon markets education · seven methods

How each method produces a tonne

How to read the step-through explainers: each one starts with a single scene and changes one thing at a time. The dashed grey bar to the right of the diagram is what would have happened anyway, the solid teal bar is what happens with the project, and the hatched band on the chart is what can be credited: the gap between the two bars for projects that avoid emissions, and the whole project bar above a zero baseline for projects that remove carbon.

DIAGRAMS ARE SCHEMATIC · PROPORTIONS ILLUSTRATE MECHANISM, NOT MEASURED VOLUMES

01 · Savanna fire management

Early dry-season burning
1GRASS FUEL2TREE CANOPYBASELINE CO2ePROJECT
END OF DRY SEASON · FUEL LOAD AT MAXIMUMBASELINE CO2ePROJECT
WITHOUT PROJECT → LATE HOT FIRESCORCH HEIGHTCO2eCO2eCO2eCO2e1ASH LEFT2FLAME TO CANOPY3CANOPY SCORCHEDBASELINE CO2ePROJECT
LATE HOT FIRE · CANOPY SCORCHED · BASELINEBASELINE CO2ePROJECT
WITHOUT PROJECT → LATE HOT FIREWITH → EARLY COOL BURNSCORCH HEIGHT1COOL LOW FLAME2CANOPY UNBURNTBASELINE CO2ePROJECT
EARLY DRY SEASON · COOL PATCH BURNSBASELINE CO2ePROJECT
WITHOUT PROJECT → LATE HOT FIREWITH → EARLY COOL BURNSCORCH HEIGHT1ALREADY BURNT2FIRE STOPSBASELINE CO2ePROJECT
LATE FIRE MEETS THE BURNT MOSAICBASELINE CO2ePROJECT
WITHOUT PROJECT → LATE HOT FIREWITH → EARLY COOL BURNSCORCH HEIGHT1LESS CARBONBASELINE CO2ePROJECT
ABATEMENT = BASELINE − PROJECTBASELINE CO2ePROJECT

Savanna at the end of the dry season

Late in the dry season the grass has dried out and there’s a lot of it. The trees are still standing and nothing has burnt yet.

01 / 05

A late-season wildfire

Without the project: fire arrives late and burns hot. It reaches up into the tree canopy and releases carbon held in the grass, leaves and wood.

02 / 05

Burning earlier instead

With the project: fires are lit early, while the grass is still damp. They burn low and cool, and don’t reach the canopy.

03 / 05

Less left to burn

When the hot part of the season comes, fire runs into ground that has already burnt and can’t spread far. Same country, only the fire has changed.

04 / 05

What gets credited

Both cases involve burning; the scenario with the project releases less. The credit is the difference between the two.

05 / 05

02 · REDD+

Forest Conservation
1FOREST BLOCKBASELINE CO2ePROJECT
FOREST BLOCK · CARBON STOCKS STANDINGBASELINE CO2ePROJECT
WITHOUT PROJECT → CLEARED FOR PASTURECLEARED / PASTURE1STUMPS2CLEARING FRONTBASELINE CO2ePROJECT
CLEARING FRONT ADVANCES FROM THE ROADBASELINE CO2ePROJECT
WITHOUT PROJECT → CLEARED FOR PASTURECLEARED / PASTURE1FRONT ADVANCESBASELINE CO2ePROJECT
MOST OF THE BLOCK IS LOSTBASELINE CO2ePROJECT
WITHOUT PROJECT → CLEARED FOR PASTUREWITH → BLOCK PROTECTEDCLEARED / PASTURE1PROTECTED2FOREST KEPTBASELINE CO2ePROJECT
BLOCK PROTECTED · PERMANENCE OBLIGATIONBASELINE CO2ePROJECT
WITHOUT PROJECT → CLEARED FOR PASTUREWITH → BLOCK PROTECTEDCLEARED / PASTURE1CARBON KEPTBASELINE CO2ePROJECT
ABATEMENT = BASELINE − PROJECTBASELINE CO2ePROJECT

A forest at risk of clearing

A block of standing forest. Its trunks, branches and roots hold carbon, and clearing is expected here.

01 / 05

Clearing begins

Without the project: clearing moves in from a road or an existing edge. Trees come down and the carbon they held is released.

02 / 05

More forest is lost

The clearing keeps going and doesn’t come back. What’s lost stays lost.

03 / 05

The forest is protected

With the project: the block is protected and the trees stay standing, so the carbon stays where it is.

04 / 05

What gets credited

The credit is the loss that didn’t happen: the gap between the forest that would have gone and the forest still there.

05 / 05

03 · Improved cookstoves

Lowered emissions, smoke, and labour
1ONE MEALBASELINE CO2ePROJECT
ONE POT · ONE MEAL · POSITION FIXEDBASELINE CO2ePROJECT
CO2eCO2eCO2eCO2e1OPEN FIRE2SMOKE3FUEL USEDBASELINE CO2ePROJECT
THREE-STONE FIRE · MORE FUEL, MORE SMOKEBASELINE CO2ePROJECT
WITHOUT PROJECT → THREE-STONE FIREWITH → IMPROVED STOVEFUEL / SMOKE PER MEAL1CLOSED STOVE2LESS FUELBASELINE CO2ePROJECT
IMPROVED STOVE · CLOSED COMBUSTION CHAMBERBASELINE CO2ePROJECT
WITHOUT PROJECT → THREE-STONE FIREWITH → IMPROVED STOVEFUEL / SMOKE PER MEAL1MORE FUEL2LESS FUELBASELINE CO2ePROJECT
FUEL AND SMOKE PER MEAL BOTH FALLBASELINE CO2ePROJECT
WITHOUT PROJECT → THREE-STONE FIREWITH → IMPROVED STOVEFUEL / SMOKE PER MEAL1FUEL SAVEDBASELINE CO2ePROJECT
ABATEMENT = BASELINE − PROJECTBASELINE CO2ePROJECT

One pot, one meal

Start with a single household meal. What changes from here is the stove underneath it, the fuel it takes and the smoke it makes.

01 / 05

Cooking on an open fire

Without the project: an open fire loses most of its heat to the air, so the meal takes more wood and fills the home with smoke.

02 / 05

A more efficient stove

With the project: an enclosed stove puts more of its heat into the pot, so the same meal needs less fuel.

03 / 05

Fuel and smoke per meal

The comparison is fuel for the same meal, side by side. Less wood burnt also means less smoke indoors and less time spent collecting it.

04 / 05

What gets credited

Wood that isn’t burnt is carbon that isn’t released. The credit is the difference between the two ways of cooking.

05 / 05

04 · Human-induced regeneration

Degraded grazing land
1BARE GROUND2GRAZING STOCKZERO BASEREMOVED CO2e
DEGRADED PADDOCK · SET-STOCKEDZERO BASEREMOVED CO2e
WITHOUT PROJECT → NO REGENERATION, ZERO REMOVALSNO REGENERATION1NO REGROWTHZERO BASEREMOVED CO2e
GRAZING CONTINUES · NOTHING RECOVERSZERO BASEREMOVED CO2e
WITHOUT PROJECT → NO REGENERATION, ZERO REMOVALSWITH → CARBON SEQUESTEREDNO REGENERATION1SEEDLINGSZERO BASEREMOVED CO2e
STOCK REMOVED · SEEDLINGS ESTABLISHZERO BASEREMOVED CO2e
WITHOUT PROJECT → NO REGENERATION, ZERO REMOVALSWITH → CARBON SEQUESTEREDNO REGENERATION1REGROWTH2CARBON STOREDZERO BASEREMOVED CO2e
WOODY REGROWTH · CANOPY CLOSINGZERO BASEREMOVED CO2e
WITHOUT PROJECT → NO REGENERATION, ZERO REMOVALSWITH → CARBON SEQUESTEREDNO REGENERATION1CARBON REMOVEDZERO BASEREMOVED CO2e
CREDITS = REMOVALS ABOVE A ZERO BASELINEZERO BASEREMOVED CO2e

Degraded grazing land

Country that has been grazed for a long time. The ground is largely bare and native vegetation has been kept from getting away.

01 / 05

Grazing continues

Without the project: the land stays as it is. Nothing much grows, so no extra carbon is stored.

02 / 05

Grazing pressure is lifted

With the project: management changes and native vegetation starts to come back. Same soil, same horizon.

03 / 05

Regeneration

Years on, the regrowth is taller and thicker, taking carbon out of the air and holding it in wood, leaves and soil. One paddock, later.

04 / 05

What gets credited

The credit is the carbon the regrowth now holds.

05 / 05

05 · Renewable energy

Clean Energy Generation
1DISPATCH UNITSBASELINE CO2ePROJECT
GRID DEMAND · DISPATCH UNITSBASELINE CO2ePROJECT
WITHOUT PROJECT → FOSSIL GENERATIONCO2eCO2eCO2eCO2e1FOSSIL UNITS2EMISSIONSBASELINE CO2ePROJECT
ALL UNITS FOSSIL · EVERY UNIT EMITSBASELINE CO2ePROJECT
WITHOUT PROJECT → FOSSIL GENERATIONWITH → RENEWABLE DISPATCHDISPLACED FOSSIL UNITSCO2eCO2eCO2eCO2e1RENEWABLE2DISPLACEDBASELINE CO2ePROJECT
TWO UNITS DISPLACED · DEMAND UNCHANGEDBASELINE CO2ePROJECT
WITHOUT PROJECT → FOSSIL GENERATIONWITH → RENEWABLE DISPATCHDISPLACED FOSSIL UNITSCO2eCO2eCO2eCO2e1SAME DEMANDBASELINE CO2ePROJECT
SAME DEMAND MET · FEWER EMISSIONSBASELINE CO2ePROJECT
WITHOUT PROJECT → FOSSIL GENERATIONWITH → RENEWABLE DISPATCHDISPLACED FOSSIL UNITSCO2eCO2eCO2eCO2e1EMISSIONS DOWNBASELINE CO2ePROJECT
ABATEMENT = BASELINE − PROJECTBASELINE CO2ePROJECT

One grid, six units

Electricity demand is met by a set of generating units feeding the same grid.

01 / 05

Powered by fossil fuels

Without the project: that demand is met by burning coal or gas. Every unit that runs emits.

02 / 05

Renewables take part of the load

With the project: wind or solar supplies some of the demand, so some of the fossil generation isn’t needed.

03 / 05

Same power, fewer emissions

Demand hasn’t changed and nobody is using less electricity. What’s changed is where the electricity comes from.

04 / 05

What gets credited

The credit is the fossil generation that was displaced: the emissions avoided by meeting the same demand more cleanly.

05 / 05

06 · Afforestation and reforestation

Tree-plantings
1BARE PLOTZERO BASEREMOVED CO2e
CLEARED PLOT · ROOT ZONE IN FRAMEZERO BASEREMOVED CO2e
WITHOUT PROJECT → NO PLANTING, ZERO REMOVALSLAND STAYS BARE1NO PLANTINGZERO BASEREMOVED CO2e
NO PLANTING · PASTURE MAINTAINEDZERO BASEREMOVED CO2e
WITHOUT PROJECT → NO PLANTING, ZERO REMOVALSWITH → PLANTED AND GROWNLAND STAYS BARE1SEEDLINGS2ROOTSZERO BASEREMOVED CO2e
PLANTED · SEEDLINGS AND ROOTS ESTABLISHZERO BASEREMOVED CO2e
WITHOUT PROJECT → NO PLANTING, ZERO REMOVALSWITH → PLANTED AND GROWNLAND STAYS BARE1BIOMASS2ROOTS DEEPENZERO BASEREMOVED CO2e
BIOMASS ACCUMULATES ABOVE AND BELOW GROUNDZERO BASEREMOVED CO2e
WITHOUT PROJECT → NO PLANTING, ZERO REMOVALSWITH → PLANTED AND GROWNLAND STAYS BARE1CARBON REMOVEDZERO BASEREMOVED CO2e
CREDITS = REMOVALS ABOVE A ZERO BASELINEZERO BASEREMOVED CO2e

A bare plot

Land with no trees on it. Carbon gets stored below ground as well as above, so the root zone is in the picture from the start.

01 / 05

The land stays bare

Without the project: nothing is planted and nothing grows, so no carbon is taken out of the air.

02 / 05

Planted

With the project: seedlings go in and put down roots.

03 / 05

Biomass accumulates

As the trees grow they pull carbon out of the air and hold it in trunks, branches, leaves and roots. Same trees, years later.

04 / 05

What gets credited

The credit is the carbon the growing trees now hold.

05 / 05

07 · Plantation forestry

Schedule 4 · transition to permanent forest
1PLANTATION2ROTATIONSZERO BASEREMOVED CO2e
SCHEDULE 4 PLANTATION · HARVEST ROTATIONSZERO BASEREMOVED CO2e
WITHOUT PROJECT → CLEARED, ZERO REMOVALSCONVERTED / CROP1CLEARED2CROPPINGZERO BASEREMOVED CO2e
HARVESTED AND CONVERTED TO CROPPINGZERO BASEREMOVED CO2e
WITHOUT PROJECT → CLEARED, ZERO REMOVALSWITH → HELD AS PERMANENT FORESTCONVERTED / CROP1KEPT FORESTZERO BASEREMOVED CO2e
HARVEST FOREGONE · TRANSITION TO PERMANENTZERO BASEREMOVED CO2e
WITHOUT PROJECT → CLEARED, ZERO REMOVALSWITH → HELD AS PERMANENT FORESTCONVERTED / CROP1GROWING ONZERO BASEREMOVED CO2e
ROTATIONS STOP · STOCKS ACCUMULATINGZERO BASEREMOVED CO2e
WITHOUT PROJECT → CLEARED, ZERO REMOVALSWITH → HELD AS PERMANENT FORESTCONVERTED / CROP1CARBON REMOVEDZERO BASEREMOVED CO2e
CREDITS = REMOVALS ABOVE A ZERO BASELINEZERO BASEREMOVED CO2e

A working plantation

A plantation grown to be cut. Trees are harvested and replanted on a cycle, so the carbon held never builds up for long.

01 / 05

Cleared for farmland

Without the project: the trees are cut a final time and the land is converted to another use, such as cropping. Carbon stops accumulating.

02 / 05

Kept as forest instead

With the project: the harvest is given up and the block is kept as forest, protected the same way a conservation project would be.

03 / 05

Held permanently

With no harvest, the trees keep growing past the point they would have been cut, and the carbon they hold keeps building.

04 / 05

What gets credited

The credit is the carbon added by the forest left standing.

05 / 05