With approximately 20 days until the event, the Foundation confirmed two back-to-back upgrades would complete the switch. The first, a consensus layer upgrade called Bellatrix, was scheduled for September 6 at 11:34:47 UTC at Beacon Chain Epoch 144896.

The second, an execution layer upgrade called Paris, would be triggered automatically once the network's cumulative mining difficulty reached a specific threshold: 58,750,000,000,000,000,000,000. That threshold, known as the Terminal Total Difficulty, was expected to be hit between September 10 and 20. The Merge ultimately completed on September 15, 2022.

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Two Upgrades, One Window, and a Critical Warning

The architecture of the Merge required node operators to update two separate software clients in parallel rather than just one. Ethereum nodes run a consensus layer client (such as Lighthouse, Lodestar, Nimbus, Prysm, or Teku) alongside an execution layer client (such as Besu, Erigon, go-ethereum, or Nethermind).

Both had to be updated and properly configured before Bellatrix activated or operators risked being stranded on an incompatible chain. "Node operators need to update both their consensus layer and execution layer clients in tandem, rather than just one of the two," the Foundation stated in its mainnet announcement.

The warning carried real urgency. Data reported by FXStreet, drawing on Ethernodes figures, showed that as of the Bellatrix upgrade date, roughly 74% of Ethereum nodes had completed the necessary updates. The remaining 26% had not. Ethereum co-founder Vitalik Buterin issued a direct public reminder to operators in the lead-up to the deadline.

To incentivize security researchers during the high-stakes period, the Foundation also boosted its bug bounty program. Critical vulnerabilities reported before September 8 were eligible for a 4x payout multiplier, bringing the maximum single bounty to $1,000,000.

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What Changed After the Switch

The economic and environmental impact of the Merge was substantial. Before the transition, Ethereum miners were receiving approximately 13,000 ETH per day in newly issued tokens. After the switch to proof-of-stake validators, that figure fell to roughly 1,700 ETH per day, an 88.7% reduction in annual issuance. At the time of the Merge, total ETH supply stood at approximately 120.52 million, with around 14 million ETH staked and roughly 441,000 validators active on the network. Validator count subsequently grew from that 441,000 baseline to over 600,000 by early 2024, reflecting sustained confidence in the proof-of-stake model.

On energy consumption, the numbers were equally stark. Pre-Merge, Ethereum's annual electricity use was comparable to that of the Netherlands, around 78 terawatt-hours per year. Post-Merge, the entire proof-of-stake network consumed approximately 0.0026 TWh annually. Per-transaction carbon footprint fell from roughly 109.71 kg of CO2 to around 0.01 kg. Ethereum's own documentation, drawing on EY Switzerland analysis, put the overall reduction at greater than 99.95%.

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Regional Stakes: South Asia and Africa

For users in South Asia, the Merge carried direct economic relevance. India ranks first globally on Chainalysis's crypto adoption index (adjusted for purchasing power parity and population), with approximately $268.9 billion in cryptocurrency transaction volume recorded during the period covered by Chainalysis's report. Pakistan ranks eighth. The Central and Southern Asia and Oceania region accounts for roughly 20% of global cryptocurrency activity. Adding further context to Ethereum's regional prominence: in Q2 2022, approximately 58% of web traffic from South and Central Asian countries to crypto services was NFT-related, predominantly Ethereum-based activity, a figure that helps explain why Ethereum held such a dominant position across the region. Ethereum and Wrapped Ethereum are among the most actively traded assets in the region, and DeFi protocols built on Ethereum accounted for 55.8% of regional transaction volume between July 2022 and June 2023, up from 35.2% the prior year.

In Sub-Saharan Africa, where crypto is used heavily for remittances and as a hedge against local currency volatility, the structural changes also mattered. Nigeria, Kenya, and South Africa rank 11th, 19th, and 30th respectively on the Chainalysis adoption index. P2P platforms account for approximately 6% of Africa's cryptocurrency transaction volume, more than double the share recorded in any other global region. That grassroots character is further reflected in transaction sizing: 95% of transfers are retail-sized transactions under $10,000, with 80% falling under $1,000. Ghana illustrates the scale of this adoption clearly, with P2P platform volume growing by roughly 400% over a two-year period.

The Merge did not directly reduce gas fees (that would require separate scaling solutions such as rollups), but analysts noted that the energy reduction may have removed a reputational barrier that had limited institutional engagement with Ethereum-based payment infrastructure in regulated markets. This dynamic was particularly relevant in documented remittance corridors such as UK-Nigeria and France-West Africa, where environmental concerns had weighed on institutional on-ramp development.

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Looking Forward

The Foundation also launched an open analytics competition in the Finalized no. 37 newsletter, offering up to $30,000 in prizes for data analysis and visualization of post-Merge network activity. The challenge ran until October 31, 2022, and drew 45 submitted blog posts. Gold prize submissions, by analysts pintail and Jannik Luhn, examined validator attestation patterns and overall network changes, while silver prize submissions analyzed the impact of MEV (maximal extractable value) relays and staking pool economics.

That community research effort helped establish the analytical baseline from which Ethereum's post-Merge network has been studied ever since.