The Nexus Forum 2025 "Carbon Neutrality and Energy System Transformation (CNEST)" Sub-Forum was successfully co-hosted by Tsinghua University’s Institute for Carbon Neutrality and the International Urban Energy Centre of the Hong Kong Polytechnic University on May 10. The forum brought together leading experts including He Kebin, CAE Academician and Director of Tsinghua’s Institute; Prof. Michael Obersteiner, Director of the Environmental Change Institute, University of Oxford; Prof. Pan Wei, former Vice-President of HKU and Head of Civil Engineering; Dr. Huang Xinwo, Head of Tencent’s CarbonX Program; Prof. Zhao Junhua of CUHK-Shenzhen; and Prof. Li Jia from Lingnan University. The session was co-chaired by Prof. Yang Hongxing (PolyU), Prof. Wang Ruzhu (SJTU), Dr. Zhai Yongping (Tencent), and Prof. Lu Xi (Tsinghua).

He Kebin delivered a keynote titled "Innovative Technologies for Carbon Neutrality", reviewing the synergy between air pollution control and climate response, and introducing Tsinghua’s research advances and the CNEST multilateral initiative. He also highlighted upcoming international efforts including the World Climate Change University Alliance and the Journal of Carbon Neutrality Science and Technology.

Michael Obersteiner discussed climate risk management and solar radiation modification under different emission scenarios, emphasizing the need for long-term adaptive strategies to meet Paris Agreement goals.

Pan Wei introduced dialectical systems theory for sustainable modular integrated construction (MiC) and infrastructure assessment, offering innovative solutions for climate-resilient development.

Huang Xinwo presented Tencent’s CarbonX Program 2.0, which supports emerging low-carbon tech in carbon removal, CCUS, CCU, and long-duration energy storage with significant funding for global teams.

Zhao Junhua shared an AI-assisted model for coupling electricity and carbon markets, demonstrating applications in cross-regional power transmission, renewable integration, and green certificate trading.

Li Jia introduced distributed direct air capture (DAC) technology, highlighting its flexibility, reduced infrastructure cost, and potential use in buildings and transport, supported by AI-accelerated sorbent development.

The broader Nexus Forum 2025 (May 8–10), co-organized by PolyU and Cell Press with support from Tsinghua, focused on “Collaborative Innovation for Smart Sustainability” through keynote forums, technical sessions, and workshops, attracting over 470 participants from more than ten countries and regions.