Ethereum's Greenhouse Gas Emissions Drop 99.97% After Proof-of-Stake Shift

According to Blockworks, the Ethereum network's greenhouse gas emissions have dropped by an estimated 99.97% since its shift to proof-of-stake, despite a significant increase in node count. This information comes from new research by the Cambridge Centre for Alternative Finance (CCAF), which has increased its crypto research efforts after launching the Cambridge Blockchain Network Sustainability Index (CBNSI) in April. The index measures Ethereum's electricity consumption before and after the Merge. The Ethereum network is currently responsible for 2.8 kilotonnes of carbon dioxide equivalent (KtCO2e) on an annualized basis, according to a CCAF report released on Friday. The report provides context for these emissions, comparing them to the emissions from five round-trip airplane flights from London to New York, the annual energy consumption-related emissions of 450 UK households, or the annual carbon sequestration capacity of 270 acres of forest. Ethereum switched to a proof-of-stake consensus model in September 2022, and the Ethereum Foundation had estimated that the Merge would reduce the blockchain's power consumption by 99.95%. However, electricity usage is only one aspect of an environmental impact assessment, as stated in the Friday report. Additional data was needed to convert electricity consumption to greenhouse gas emissions. The CCAF used off-chain data from the peer-to-peer communication of Ethereum nodes to gather both electricity usage and the geolocational distribution of nodes. Since April 1, the number of Ethereum validators has grown by 57%, reaching 880,822, while Ethereum nodes have increased to 14,072, reflecting a 23.2% growth over that period. The network's annual electricity consumption increased by 21.2% in those eight months, from 6.19 GWh to 7.50 GWh, which is roughly the annual electricity use of 2,000 English households, according to Cambridge data. Following the Merge, Europe and North America are home to 43.3% and 40.5% of Ethereum nodes, respectively. The CCAF estimates that pre-Merge greenhouse gas emissions were about 10.3 MCO2e, while the latest post-Merge figure of 2.8 KtCO2e represents a 99.97% drop, despite the substantial increase in the number of Ethereum nodes. The network is now powered by nearly 48% sustainable energy, including 32% renewables and 16% nuclear, with the remaining 52% coming from natural gas, coal-fired power, and oil. The CCAF plans to enhance its Cambridge Bitcoin Electricity Consumption Index (CBECI) next, acknowledging that Bitcoin's proof-of-work consensus model is a cornerstone of its identity, making a similar transition not as straightforward as it might appear at first glance. The research institute adds that the different paths of Ethereum and Bitcoin reflect not only technological advancements but also the different ideologies and priorities of their communities, highlighting the multifaceted complexity inherent in the evolution of leading blockchain networks.