Lifecycle carbon of compute
Compute does not become zero-carbon when its electricity becomes green.
Abstract. This programme defines a full lifecycle carbon boundary for compute: semiconductor manufacturing, hardware integration, data-center infrastructure, electricity, cooling, shared network/storage, replacement and end of life. The result is allocated to useful compute and can then be translated into a carbon-limited capacity.
Seven carbon sources are kept visible until the final allocation.
The method separates semiconductor, hardware, facility, electricity, cooling, shared services and replacement/end-of-life so that upstream evidence remains inspectable instead of disappearing inside one factor.
All terms must first share the same system boundary and allocation denominator.
As electricity gets cleaner, carbon does not disappear — its relative weight moves upstream.
The visual below is a qualitative scenario, not a measured percentage dataset. It illustrates the accounting consequence of sharply reducing operational electricity carbon while manufacturing and infrastructure remain.
Grid-intensive operation
Low-carbon electricity
Normalized schematic only. The actual shares are calculated from the declared hardware, facility, electricity, lifetime and manufacturing evidence for each assessment.
The existing cloud model remains the operational-carbon layer — not the whole lifecycle.
At PUE 1.135, 1,000 kWh of IT energy becomes 1,135 kWh of facility energy. Across the six reference electricity contexts, the operational result spans 90.1–1,080.3 kgCO₂e per MWh IT.
Location-based, procurement-based and lifecycle electricity factors remain separate evidence statements.
Cooling contributes through energy, refrigerants and embodied infrastructure.
Cooling electricity
Included through PUE when using a top-down facility model, or measured directly in a bottom-up model.
Refrigerants
Leakage is a separate greenhouse-gas source and is not electricity carbon.
Cooling plant
Chillers, pumps, heat exchangers and other cooling assets contribute manufacturing and construction carbon.
Bottom-up cooling energy replaces the relevant facility-overhead estimate; it is not added a second time.
Facility embodied carbon also includes building structure, transformers, UPS, switchgear, batteries and power distribution. Those assets are allocated by service life, capacity and workload share.
The lifecycle inventory becomes useful only after it is assigned to delivered compute.
Chip + hardware
Allocate manufacturing carbon by lifetime utilization, GPU-hours, delivered FLOPs or another declared useful-work denominator.
Facility
Allocate building and equipment embodied carbon by capacity × time × utilization share.
Network + storage
Allocate shared service carbon by traffic, storage-hours or a documented service allocation.
Output units can be kgCO₂e/GPU-hour, kgCO₂e/job, gCO₂e/1k tokens or another reproducible compute denominator.
Lifecycle carbon can become a binding capacity constraint.
Once full lifecycle carbon is expressed on the same compute and time boundary, a stated emissions budget can be converted into maximum supportable compute.
The result is normalized to the same time and capacity basis as power, grid, water, cooling and other Critical Load constraints.
The final carbon number must expose what was measured, modelled and allocated.
| Layer | Evidence class | Example record | Release rule |
|---|---|---|---|
| Semiconductor | Primary / modelled | fab inventory, yield, package | carry CL-SCM version |
| Hardware | Reported / modelled | product PCF, lifetime | declare product boundary |
| Facility | Reported / modelled | construction and equipment carbon | declare capacity-time allocation |
| Electricity | Measured / contextual | kWh, PUE, grid factor | state electricity claim type |
| Cooling | Measured / reported | energy, refrigerant, cooling assets | state PUE overlap treatment |
| Lifecycle compute carbon | Derived | kgCO₂e/GPU-hour or job | carry all upstream evidence IDs |