The Ethereum ecosystem has powered many tools and services that have disrupted business models or invented new ones - new financial instruments, governance models, cross border payments and many more. The rise in Ethereum’s popularity led to problems such as high costs, high energy consumption, network congestion and scalability. Ethereum co-founder Vitalik Buterin has coined this challenge as the Blockchain Trilemma. The blockchain trilemma represents the difficulty of achieving high levels of security, scalability, and decentralization simultaneously in a blockchain system, as there are often trade-offs involved in optimizing these attributes.This poses a big challenge for Ethereum for mainstream use.

Ethereum has a set of upgrades to address this trilemma.These upgrades aim to reform Ethereum to enhance scalability, security, sustainability, and decentralization for the benefit of current users and to attract new ones. Here’s a brief overview of roadmap of these upgrades - 

Merge 

The Merge happened on 19th September, 2022. The main purpose was to transition Ethereum from a Proof-of-work (PoW) to Proof-of-stake (PoS) consensus transaction validation. This reduced the energy consumption of the network by 99.95% immediately and has made Ethereum ESG compliant. Ethereum’s carbon footprint was decreased from 11,016,000 to 870 tonnes.

Surge

The Surge is the upcoming phase in Ethereum’s upgrade roadmap. The main goal is to achieve a network throughput of 100,000 transactions per second from less than 50 transactions per second through sharding. Therefore, the Surge should reduce network congestion, increase transactions per second and reduce gas fees. 

Verge

The Verge aims to eliminate the need for network validators to hold Ethereum's entire transaction history through the use of Verkle Tree, which is currently a storage demanding and time-consuming requirement. The Verge will attract new participants to become network validators as verifying blocks should become easier. This should lead towards higher decentralization of the Ethereum ecosystem. 

Purge

The major objective of the Purge is to reduce network traffic and increase transaction speed. This involves multiple improvements to eliminate clients to hold past network data and streamline the network gradually to reduce congestion and hardware cost. 

Splurge 

The Splurge would be the final phase in the roadmap. So what is next for the Ethereum - to infinity and beyond.This might include the nice to have stuff in the Ethereum ecosystem once all of the preceding phases have been completed. 

The roadmap is not set in stone, adapting to challenges and needs, with both long-term and short-term strategies for Ethereum's growth. The primary objective is to enhance Ethereum's scalability, security, and decentralization.