Ulsan

Ulsan demonstrates keystone species economics at city scale—where a single corporate organism shapes the entire urban metabolism. Hyundai's presence defines this industrial city: the world's largest automobile assembly plant, the world's largest shipyard (Hyundai Heavy Industries), and the world's third-largest oil refinery (SK Energy). The Ulsan Mipo National Industrial Complex alone produces ₩147.3 trillion annually and exports $59.3 billion—ranking first among all Korean industrial complexes.

This concentration generated Korea's highest GDP per capita ($65,352 in 2020) through extreme industrial specialization. 780 companies including SK Energy, Hyundai Motor, Hyundai Heavy Industries, Lotte Chemical, and Hanwha Solutions cluster in the industrial zone. The petrochemical sector produces ₩153 trillion annually, making Ulsan Korea's largest petrochemical city. Saudi Aramco's S-Oil is constructing the Shaheen petrochemical project at its 669,000 barrel/day refinery, with test runs scheduled for late 2025.

Yet this keystone dependency creates transition risk. SK Geo Centric considers shutting its Ulsan naphtha cracker as Korea's petrochemical industry restructures—capacity reductions that could cascade through supplier networks. The city's response is hydrogen: the Ulsan Green Hydrogen Town project aims to transform the industrial base toward carbon neutrality, leveraging existing petrochemical infrastructure for hydrogen production and distribution. Ulsan's 2021 designation as Smart Green Industrial Complex and 2023 selection as secondary battery leader signal diversification strategy. Whether hydrogen becomes a new keystone or merely a supplementary niche will determine if Ulsan can evolve beyond its Hyundai-dependent metabolism.