The “London” hard fork upgrade was deployed on the Ethereum (ETH) network. The upgrade introduced various Ethereum network improvements through Ethereum Improvement Protocols (EIPs) 1559, 3554, 3198, and 3541.
EIP-1559
Overview: Deploys a new transaction pricing mechanism that includes fixed-per-block network fee that is burned and dynamically expands/contracts block sizes to deal with transient congestion.
Effect: Reduces gas fee volatility, improves fee market efficiencies, and counter-balances the increasing supply of ETH.
EIP-3529
Overview: Reduces, and in some cases eliminates, the gas fee refunds that were initially introduced to incentivize developers to discard unused Ethereum smart contracts and addresses.
Effect: Essentially eliminates “gas tokens” like Chi and GST2 that would leverage fluctuations in gas fees to maximize returns on gas refunds
EIP-3554
Overview: Delays the difficulty bomb (“Ice Age”) to the first week of Dec. 2021.
Effect: The difficulty bomb is designed to make mining on Ethereum so difficult that it “freezes” participation in the PoW protocol. With Ethereum 2.0 transitioning to a PoS protocol, this could suggest the merge of Ethereum 2.0 could happen by the end of this year.
EIP-3198
Overview: Adds an opcode that gives the EVM access to the block’s base fee.
Effect: Provides an easier and more predictable way for developers to estimate costs and improve efficiencies for gas fees within dApps.
EIP-3541
Overview: Disallows new code starting with 0xEF byte to be deployed. Code already existing in the account trie starting with 0xEF byte is not affected semantically by this change.
Effect: EIP-3541 will not have an immediate effect but will set the foundation for future upgrades to the Ethereum Virtual Machine (EVM).
