Ropsten, Ethereum's oldest and longest-running public test network, completed its shift from proof-of-work to proof-of-stake consensus on June 8, 2022, at approximately 12:10 PM ET. The Ethereum Foundation announced the upgrade on May 30, opening an eight-day preparation window for node operators worldwide, with a deadline of June 7. The event marked the first time a major, longstanding Ethereum testnet had gone through the protocol change developers call "the Merge," and it served as the most consequential rehearsal yet for a mainnet transition that would affect millions of users across South Asia, Sub-Saharan Africa, and beyond.

How the Transition Worked

The Merge unified two chains that had been running in parallel. Ethereum's original proof-of-work chain (the execution layer) was joined to the Beacon Chain (the consensus layer, live since December 2020) into a single network. The transition required two separate triggers to fire in sequence. The Bellatrix upgrade activated at slot 24,000 on the consensus layer around June 2. The Paris upgrade then fired once the execution layer crossed a Terminal Total Difficulty of 50,000,000,000,000,000, a cumulative measure of all mining work performed on the chain. Once that threshold was crossed, mining on Ropsten ended permanently. Under proof-of-stake, validators replace miners; to participate, a validator must lock up a minimum of 32 ETH as collateral.

Ropsten was chosen specifically because it was the only major Ethereum testnet still operating on proof-of-work. Other testnets used proof-of-authority, where a fixed set of trusted parties approve blocks rather than miners competing to solve cryptographic puzzles. That approach is easier to manage but does not accurately replicate mainnet conditions. The Ethereum Foundation described the full Merge process as "the most complicated upgrade to Ethereum to date." Vitalik Buterin called the Ropsten rehearsal "a major test, larger than any of the tests that we have done before."

From Ropsten to Mainnet

Ropsten's success cleared the way for two further rehearsals on longstanding testnets (the purpose-built Kiln testnet had run a separate Merge trial in March 2022, but on a proof-of-authority basis and not as a preexisting network). Sepolia merged on July 6 and Goerli on August 11, before Ethereum's mainnet completed the same transition on September 15, 2022. ETH rose 1.98% on the day of the Ropsten Merge. The Ethereum Foundation subsequently announced that Ropsten, along with Rinkeby and Kiln, would be deprecated. Goerli and Sepolia were designated as the long-term supported testnets. Ropsten's retirement, after six years as Ethereum's oldest testing ground, was already built into the plan; the Ethereum Foundation announced the deprecation on June 21, 2022, shortly after the Ropsten Merge itself.

South Asia: Developer Community With Direct Exposure

For developers and infrastructure operators in India and Pakistan, the Ropsten testnet window was directly actionable. India ranked fourth on Chainalysis's 2022 Global Crypto Adoption Index, and Pakistan ranked sixth on the same index. The broader Central and Southern Asia and Oceania region transacted $932 billion in crypto between July 2021 and June 2022, placing it third globally by volume. India alone accounted for $172 billion of that. ETH, wrapped ETH, and stablecoins ranked among the most actively traded assets in the region, consistent with a user base oriented toward DeFi (decentralized finance, or financial services that run directly on blockchain protocols) and cross-border remittances, where stablecoin use is particularly prevalent.

India hosts ETHIndia, cited by Outlook India as the world's largest Ethereum hackathon. For node operators and application developers in that ecosystem, the Ropsten period was a critical window to test the new two-client architecture introduced by the Merge. Every node operator globally needed to update their software to authenticate between execution and consensus clients before the June 7 deadline or risk losing sync with the canonical chain.

India's regulatory environment added its own pressure. A 30% capital gains tax on crypto took effect in April 2022, followed by a 1% tax deducted at source on every transaction set to begin in July. Retail trading volumes dropped and India fell from second to fourth on the adoption index. According to Chainalysis's regional reporting, developer activity held firm regardless.

Sub-Saharan Africa: Energy Reduction With Institutional Weight

Sub-Saharan Africa recorded $100.6 billion in on-chain crypto volume during the same period, with Nigeria ranking 11th globally on the adoption index, Kenya 19th, and South Africa 30th. Peer-to-peer exchange volumes accounted for roughly 6% of African crypto activity, more than double any other region, reflecting limited access to centralized exchange infrastructure. The primary use cases were wealth preservation, remittances, and cross-border commercial payments rather than speculative trading.

The mainnet Merge that Ropsten was rehearsing ultimately cut Ethereum's electricity consumption by 99.988% and carbon emissions by 99.992%. Joseph Lubin, co-founder of Ethereum and CEO of Consensys, called the transition "likely the biggest decarbonization effort of any industry in history." That reduction carried particular weight in sub-Saharan Africa, where the proof-of-work energy footprint had represented a significant ethical objection for climate-conscious NGOs, development finance institutions, and green bond markets considering Ethereum-based applications. Analysts noted that removing this barrier opened a more direct path for those organizations to engage with Ethereum-based tools across the continent.

What Came After

Ethereum's mainnet Merge completed on September 15, 2022. Ropsten had already been slated for retirement: the Ethereum Foundation announced its deprecation on June 21, 2022, shortly after the Ropsten Merge itself, with Rinkeby and Kiln scheduled alongside it. For users across Lagos, Nairobi, Mumbai, and Karachi whose financial activity ran through Ethereum-based applications, the June 8 testnet transition marked an opening window in the final preparation period for a protocol change with no precedent at that scale in blockchain history.