Climate governance credibility and renewable energy transition in G20 nations: an institutional signalling perspective on NDC compliance and implementation gaps (2016–2024)

IntroductionA core credibility problem exists in global climate governance: G20 nations collectively account for approximately 77% of greenhouse gas emissions, yet systematically diverge between their publicly signalled commitments and actual implementation under the Paris Agreement framework. This study examines NDC implementation gaps from an institutional signalling perspective, treating Nationally Determined Contributions as credibility-bearing commitments whose realisation depends on the in