In this opening chapter, the editors of Architectural Thinking in a Time of Climate Emergency critically examine the role of architects and architecture in the era of the climate emergency, underlining how the built environment significantly contributes to environmental degradation through high carbon emissions, resource extraction, and unsustainable practices. The editors contend that traditional architectural thinking – rooted in competitive, market-driven models and narrow design paradigms – is insufficient to address the intertwined crises of climate change, biodiversity loss, and social injustice. The conventional focus of architectural practice on quantifiable metrics of environmental performance, such as carbon emissions, often neglects qualitative aspects like user well-being, ecological balance, and social equity. In light of this, an optimistic definition of architectural thinking is offered: an embodied, multi-modal process that involves both divergent and convergent modes of thought, merging creative, hands-on making with critical reflection. This vision of architectural thinking as a necessary response to the climate emergency contrasts with the normative design thinking that got us into this situation, emphasising our connectivity to historical, cultural, and professional contexts. Looking ahead to the chapters in the book, this chapter advocates for a radical transformation in both architectural practice and education, calling for a more holistic, collaborative, and inclusive approach. By learning from innovative case studies and global precedents, the editors suggest that architects must reframe their role to become proactive change-makers who can embrace a renewed, socially and environmentally responsible mode of thinking that prioritises global citizenship, ecological justice, and transformative practices.