HSC 2025 provides possible solutions to global challenges

This was echoed by Peter Tschentscher, Mayor of Hamburg, who stressed: "Global developments can only be achieved by joining forces and working together." As host of the sustainability conference, Hamburg can input practical experience as people from over 180 nations live in Hamburg. Smart framework conditions boost the opportunities arising from a multinational urban society while taking into account the ecological consequences of urban life. "More than half of the world's population lives in urban areas. They consume 80 per cent of the world's energy, are responsible for 70 per cent of greenhouse gas emissions and produce more than half of all waste," Tschentscher noted. Thus, global cities have a special responsibility and hold the potential to develop solutions for a sustainable future. "Hamburg is ready for this and committed in 2017 to consistently implementing the UN Sustainable Development Goals (SDGs)."

In February, Hamburg also adopted a climate adaptation strategy to make the city more resilient and to counter extreme weather events such as heatwaves, droughts, heavy rainfall and storm surges. "More resilience means a better quality of life," said Tschentscher. Various panels on the future of urban area saw resilience as a catalyst of growth.

Thus, investments in resilient structures benefit both the environment and the economy. Alois Rainer, Germany's Minister for Agriculture, stressed the importance of climate-adapted agriculture and saving water, and cited measures in Germany's National Water Strategy. Europe's cross-border approach is also notable, and added: "The EU is working on a water resilience strategy, which is due to be adopted shortly." The UN's Water Conference in December 2026 seeks to advance the sixth SDG of ensuring clean water and sanitation for everyone. Meanwhile, the Munich-based Vista Geowissenschaftliche Fernerkundung GmbH has come up with a technical means of counteracting water scarcity. "We use machine learning and AI for monitoring agriculture, smart farming, sustainability and climate change," said founder Heike Bach. By developing digital twins, savings of 20 per cent in water, energy and fertiliser can be achieved. "So far, we have been particularly active in the Global South. However, climate change means that we are increasingly focussing on the Global North," Bach said.

AI is also being used in the Hamburg Metropolitan Region to boost source-conserving agriculture. The joint Smart Automation Systems and Services for Fruit Cultivation on the Lower Elbe (SAMSON) project, for instance, is developing digital twins for apple orchards in the Altes Land region. Blossoms in spring and the number and even the diameter of apples in autumn can be displayed precisely in just one click. AI holds enormous potential for agriculture, transport, health or the energy sector. However, the world's population can barely keep up with the rapid technological developments making the need for global agreements and regulations all the more pressing. Thus, the signing of the "Hamburg Declaration on Responsible AI for Sustainable Development Goals" during HSC proved a "real milestone", according to Achim Steiner, Head of the UN Development Programme. 

The future of AI must be considered globally, he added. "This declaration means we recognise that AI can be used as a weapon or as a tool for humanity." Steiner expressed hope that the declaration, signed by representatives of more than 40 governments, private sector organisations, society and leading research institutions, will go a long way towards ensuring the latter. "The declaration is a key commitment to using AI responsibly, to improving justice, connecting communities, and reducing global inequalities. This second HSC marks a step towards the brand Steiner, stressed. 

Efforts will now focus on substantiating the agreements before the next HSC on June 29-30, 2026. The Scaling Capital for Sustainable Development (SCALED) declaration of intent to mobilise private investment for sustainable development was also signed. A global alliance against inequality was also established to boost cross-regional cooperation, political talks, innovation, and public trust, with the aim of creating peaceful and just societies.

Trust was a buzzword at HSC. During the opening panel, Reem Alabali-Radovan, German Minister for Economic Cooperation and Development, stressed the importance of trust-based talks and talking to each other rather than about each other. And Rebeca Grynspan, Secretary-General of United Nations Trade and Development (UNCTAD), called for more trust in multilateralism, which has been damaged by rising nationalism. However, the multilateral system needs to be rethought, according to Debapriya Bhattacharya, Distinguished Fellow at the Centre for Policy Dialogue (CPD), who stressed: "We need a multilateralism that includes everyone and is based on participation, openness and reliable rules." Asked whether he considers this utopian, Steiner begged to differ and noted: "Anyone who is really interested in the future and wants to get involved will find partners. And then the impossible becomes possible."
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