Why Leadership Capability Has Become the Binding Constraint in Global Governance: Evidence-Informed Leadership in an Age of Polycrisis

Executive SummaryThe global system is experiencing a sustained polycrisis characterised by climate instability, pandemics, conflict, economic fragility, technological disruption, and declining institutional trust. Despite unprecedented access to data, analytics, and scientific evidence, governments and multilateral institutions continue to struggle with policy implementation and coordinated action.This policy brief advances a central proposition: the primary constraint on effective global problem-solving is no longer evidence scarcity, but leadership capability under conditions of uncertainty and complexity. Drawing on behavioural science and institutional analysis, the brief reframes leadership as a decision-making system shaped by cognitive limits, organisational incentives, political pressures, and institutional design.The brief offers a diagnostic framework and actionable implications for global institutions seeking to strengthen evidence-informed governance, restore public trust, and improve collective outcomes.