Cardano Carbon Footprint

Cardano Layer 1 Carbon Emissions: A 2024 Study

Acknowledgments and Contributions

We are privileged to share this white paper on the carbon footprint of the Cardano blockchain, a project sparked and shaped by the collaboration of many, whom I deeply thank.

White paper research and Authors:

Authors:
Christian Unger, SHIFT – Stake Pool Operator
Hamish Cunningham, SHIFT – Stake Pool Operator

Supporting Author:
Scott Poynton, Founder and Board President, Pond Foundation

Expert reviewer:
Michele Soavi, COO/CSO at ImpactScope, Chair of the Sustainability WG at Crypto Valley Association

Initial Discussions and support:
Sam Ashworth, Pond Foundation

Proof Reading:
Sarah Boddy, SHIFT Pool Supporter

Active Members of the Climate Neutral Cardano Stake Pool Alliance, specific thanks go to:

Rick Carstens, RCADA Pool, Climate Neutral Cardano – Active Member
Leon, HAPPY Pool, Climate Neutral Cardano – Active Member
Devin Field, YOON Pool, Climate Neutral Cardano – Active Member
Lauren Zawodni, HODLR Pool, Climate Neutral Cardano – Active Member
Stephen Castermans, BEADA Pool, Climate Neutral Cardano – Active Member
Stefan , Founder of Climate Neutral Cardano

Community Connections and Catalyst Support:
Yoram Ben-Zvi, Cardano 4 Climate
Melanie Russo, Cardano 4 Climate

We thank the Cardano Community, Catalyst, and the Cardano Foundation for their environmental care and funding.

Endorsement from Pond Foundation

Pond Foundation is a Swiss-based, international non-profit that supports organizations to determine their carbon footprint. We do this for Pond Foundation member companies and as consultants for non-members. Our emissions calculations have been verified by Inteco, an ISO accredited auditor, as being completed in accordance with ISO standard ISO14064-1 Greenhouse gases: Quantification and reporting of greenhouse gas emissions and removals. 

Pond Foundation has engaged with Christian Unger, of SHIFT Pool to review this Carbon Footprinting White Paper for Cardano Layer 1. We consider it to be a high quality, foundational report that not only provides a first calculation of the Cardano blockchain’s footprint, but that provides a strong basis for further discussions and considerations for future additions and amendments to the reporting logic.

Our experience with calculating carbon emissions according to ISO14064-1 is that it’s critical to lay out all the assumptions and the scope, boundaries, and accounting methodology. This provides the basis for objective review and discussion. Defining the boundaries is a challenge with blockchain emissions calculations but the White Paper overcomes this challenge with great clarity and reasoning. It’s less important that the reasoning is 100% correct than it is to be clear. This allows an informed discussion and debate as to what could or could not be included in the future. The White Paper does this.

The White Paper also describes clear logic on inclusions and exclusions, and again, provides a strong basis for the broader Cardano community to debate the points and to change the calculation approach in the future, should they decide to do so. Critical here is that the White Paper has established a foundational baseline and a path to ongoing development and refinement of the calculations.

The approach to calculate Scope 1 and 2 emissions is correct and in accordance with the ISO14064-1 standard. At this stage, it’s too premature to include a full accounting of Scope 3 emissions, but again, the White Paper provides a good discussion and rationale for future inclusions and expansion, at least to include some of the easier to calculate Scope 3 emissions.

It is our view that the White Paper is an excellent piece of work. We acknowledge that we are conflicted in this statement by the fact that we are one of the partners to the Project Catalyst project that funded the Paper’s development. That said, it’s not in our interest to praise or discredit. It’s important to us to maintain our credibility, and in this respect, we’re happy to state unequivocally that we believe the report to be an excellent foundational calculation for Cardano Layer 1 carbon emissions.

Scott Poynton

Introduction & Purpose of the Study

We are pleased to announce the publication of The Cardano Carbon Footprint, an initial effort to establish a standardised and transparent carbon accounting methodology for the Cardano blockchain. Developed by dedicated members of the Cardano community and funded through Project Catalyst, this research addresses the complexities of measuring blockchain-related carbon emissions.

The study focuses solely on Cardano’s Layer 1 blockchain, explaining the chosen scope, challenges encountered, and key assumptions underpinning the analysis. Using 2024 data as a case study, it provides robust energy consumption and emissions estimates, aligned with the Greenhouse Gas (GHG) Protocol. A location-based methodology estimates Scope 1 emissions (from direct on-site combustion) and Scope 2 emissions (from electricity use).

Existing blockchain carbon accounting often underestimates emissions by overlooking decentralised sources, such as stake pool operators’ home office energy consumption. This research addresses that gap and, with expert input, proposes a 20% uplift to ensure a more comprehensive assessment.

This approach to evaluating the network’s environmental footprint aims to establish a basis for continuous tracking and improvement as the ecosystem evolves.

Key Findings & Summary of Results

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Cardano’s Proof-of-Stake design enables a highly decentralized network with significantly lower energy consumption and emissions than Proof-of-Work blockchains like Bitcoin. Based on the Cardano Carbon Footprint White Paper, its estimated annual carbon footprint is 867.2 tCO₂, approximately 99% lower than Bitcoin, with real-time updates based on active stake pool data.

Summary of 2024 Cardano Layer 1 Carbon Emissions

Metrics	Value	Description
Mean Number of Cardano Stake Pools	3094	Mean number of total stake pools operating throughout the year 2024.
Annual Electricity Consumption of Cardano Software Nodes	2,079,320.25 kWh (2.08 GWh)	Total electricity consumption of all Cardano Layer 1 Stake Pool servers.
Scope 1 Emissions	156.2 tCO₂e	Direct greenhouse gas emissions from stake pool operator (home) office heating with fossil fuels (i.e. gas).
Scope 2 Emissions	710.3 tCO₂	Indirect emissions from electricity consumption of stake pool servers and Stake Pool Operator (home) office equipment.
Total Carbon Footprint	867.2 tCO₂	Combined annual greenhouse gas emissions from direct operator activities (Scope 1) and electricity consumption (Scope 2).
Total Carbon Footprint Including 20% Up-Lift	1052.319 tCO₂	A 20% uplift is applied to ensure that carbon emissions are not underestimated and provides additional protection for our climate.

Carbon Accounting Methodology & Scope

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Calculating Carbon Emissions

To estimate the carbon footprint of Cardano’s Layer 1 operations, this study follows standard carbon accounting formulas based on the Greenhouse Gas (GHG) Protocol. The total emissions are calculated using the following general formula:

Carbon Emissions = Energy Consumption (unit i.e. kWh) × Carbon Emission Factor (kg CO2e/ unit)

For Scope 1 (Direct Emissions from fossil fuel combustion), the heating demand of Stake pool operator (home) offices for the time they do essential Cardano Stake Pool maintenance has been multiplied based on the hours they work annually with a carbon factor for gas heating.

For Scope 2 (indirect purchased electricity), the calculations takes the electricity consumed by the Cardano Nodes and the office equipment of Stake Pool Operators while they do essential maintenance. This electricity consumption is then multiplied by the weighted average electricity grid emissions based on Cardano relay locations distribution.

Input Data for the 2024 Cardano Footprint Estimate

The following parameters were used to estimate Cardano’s energy consumption and carbon emissions for 2024:

Metric	Value	Description
Mean Total Stake Pool Number (2024)	3094	Average number of active energy consuming stake pools throughout 2024.
Number of Energy-Consuming Nodes per Stake Pool	3	Estimated number of block-producing and relay nodes per stake pool.
Average hourly Carbon Footprint of Pool Operator for gas heating	0.30234 kg CO₂e per FTE Working Hour	UK Carbon Emissions Factor for home office heating in 2024. The factor takes into consideration heating and non-heating months. UK data was used as representative for a majority of Stake Pools are located in countries with gas heating.
SPO Work Time for Essential Maintenance	167 hours per year	Estimated time per year spent on essential stake pool maintenance.
Average Node Electricity Consumption	25.5W	Estimated power usage of a single Cardano node.
Cardano Relay Location-Weighted Carbon Emissions Factor	0.33375 kg CO₂ / kWh	Weighted average of electricity grid emissions based on relay locations.

For details on how these parameters were determined, refer to the Cardano Carbon Footprint White Paper.

Exclusions from the Carbon Accounting Scope

The following Cardano Layer 1 -related sources of emissions have been excluded in this Carbon Accounting, and the reasoning has been discussed in more detail in the white paper:

• SPO emissions not essential to node operations (e.g., time spent marketing stake pools).
• Emissions from Cardano-affiliated organizations (e.g., Input Output, Cardano Foundation).
• Emissions from Cardano applications (e.g., wallets, dApps).
• Energy consumption from Testnet operations.
• Emissions from Catalyst governance activities.

We would like to encourage an ongoing discussion within the community to decide whether or not these exclusions are considered essential (or are in the process to become essential) and if so to include them into a later iteration of the Cardano Layer 1 Footprint.

Blockchain Carbon Footprint Estimates: Cardano, Bitcoin & Ethereum

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Carbon footprint calculations vary by blockchain due to differences in consensus mechanisms, transaction structures, and accounting methodologies. The following estimates are based on publicly available research, with Bitcoin and Ethereum figures sourced from the Cambridge Blockchain Network Sustainability Index (CBNSI), which provides a transparent methodology for emissions tracking. Cardano’s footprint is derived from the Cardano Carbon Footprint White Paper.

Blockchain Energy & Carbon Comparison

Blockchain	Annual Carbon Footprint (tCO₂e)	Source
Bitcoin	94.85 MtCO₂e	Cambridge Blockchain Network Sustainability Index
Ethereum 2.0	1,780 tCO₂e	Cambridge Blockchain Network Sustainability Index
Ethereum 1.0 (Pre-PoS)	1.78 MtCO₂e	Cambridge Blockchain Network Sustainability Index
Cardano	867.2 tCO₂e	Cardano Carbon Footprint White Paper

Cardano’s carbon footprint remains significantly lower than Bitcoin and pre-PoS Ethereum due to its energy-efficient Proof-of-Stake design. While different blockchains use varying methodologies for emissions accounting, the estimates above are sourced from the most transparent and reliable studies available. For full details, refer to the Cardano Carbon Footprint White Paper and the Cambridge Blockchain Network Sustainability Index.

Real-Time Cardano Network Metrics

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Blockchain sustainability in real time: The figures below are automatically updated every hour using the latest data from the Cardano network. Power consumption and carbon footprint estimates are based on registered stake pools and the current epoch.

The figures below are annual electricity and emissions estimated based on this current  Epoch’s Stake Pool numbers.

Live Cardano Network Energy & Emissions Overview

Metrics	Value
Annual Node Network Electricity Consumption	2,020,444.66 kWh
Annual CO₂ Scope 1	152.5 tCO2
Annual CO₂ Scope 2	699.6 tCO2
Annual CO₂ Total	852.1 tCO2
Annual CO₂ Total Including 20% Up-Lift	1022.52 tCO2

average emission per transaction in 2024

Based on our own carbon accounting in this white paper (867.2 tonnes) and the estimated number of transactions in 2024 (21,681,700, Data Source: Cardano Spot), the Cardano transaction footprint is calculated to be **0.0404 kg CO₂** (or **40.4g CO₂**) per transaction in 2024.

Summary & Further Reading

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Cardano’s Layer 1 carbon footprint is significantly lower than Proof-of-Work blockchains, with a total annual emissions of 867.2 tCO₂ (1052.319 tCO2 incl 20% uplift). This work lays the foundation for transparent and data-driven carbon accounting in the blockchain space.