Carbon markets play an important role in firms’ and governments’ climate strategies. Carbon crediting mechanisms allow project developers to earn carbon credits through mitigation projects. Several studies have raised concerns about environmental integrity, though a systematic evaluation is missing. We synthesized studies relying on experimental or rigorous observational methods, covering 14 studies on 2346 carbon mitigation projects and 51 studies investigating similar field interventions implemented without issuing carbon credits. The analysis covers one-fifth of the credit volume issued to date, almost 1 billion tons of CO₂e. We estimate that less than 16% of the carbon credits issued to the investigated projects constitute real emission reductions, with 11% for cookstoves, 16% for SF₆ destruction, 25% for avoided deforestation, 68% for HFC-23 abatement, and no statistically significant emission reductions from wind power and improved forest management projects. Carbon crediting mechanisms need to be reformed fundamentally to meaningfully contribute to climate change mitigation.

This paper examines the relationship between corporate activities to address climate change and stock performance. By separately analyzing the US and European stock markets for different sub-periods, we highlight the impact of the underlying climate policy regime. Methodologically, we compare risk-adjusted returns of stock portfolios comprising corporations that differ in their responses to climate change. In this respect, we apply the flexible Carhart four-factor model besides the restricted one-factor model based on the Capital Asset Pricing Model (CAPM). While our portfolio analysis shows negative relationships over the entire observation period from 2001 to 2006, we find that a trading strategy, which bought stocks of corporations with a higher level of responses to climate change and sold stocks of corporations with a lower level, led to negative abnormal returns in regions and periods with less ambitious climate policy, but to positive abnormal returns in regions and periods with stringent climate policy.

Understanding the long-term patterns of innovation in energy technologies is crucial to informing public policy planning in the context of climate change. This

We analyze how a product's design hierarchy shapes the evolution of the underlying body of technological knowledge, building on the literature on technological

The European Green Deal requires policy alignment horizontally across policy areas but also vertically across governance levels. Accordingly, the diversity of actors and their preferences can hinder sociotechnical transitions. We, therefore, ask: How do policy mixes unfold across vertical scales of governance in sociotechnical transitions? We analyse vertical policy mix characteristics, considering consistency, coherence, comprehensiveness, and credibility, and the inherent feedback loops between politics and policy. Drawing on empirical evidence from Latvia, gathered through content analysis and interviews with senior stakeholders, we highlight two aspects: First, policy strategies do not automatically flow top-down across governance levels. Without political commitment at all levels, a comprehensive set of policy instruments does not emerge. Second, vested interests shape policy processes, reducing bottom-up political commitment to the transition and with that the credibility of the overall vertical policy mix.