How Credible are Climate and Energy Targets?: Evolution and Performance of National Renewable Targets

Mitigating climate change requires a significant acceleration in energy transitions, particularly through the rapid development of renewable energy technologies. While the need for such acceleration is widely recognised, current efforts remain insufficient to meet the Paris climate goals. Countries are thus requested under the ratchet-up mechanism to set increasingly ambitious climate mitigation targets. The prevailing assumption is that raising national targets increases the likelihood of successfully mitigating climate change, yet growing evidence highlights persistent implementation gaps. Why do such gaps exist? Do more ambitious targets effectively accelerate energy transitions or merely perpetuate unrealistic expectations? This paper addresses these questions by analysing renewable energy targets set by G20 countries since 2000. The study pursues three objectives: (1) to evaluate the extent to which these targets have been under- or overachieved; (2) to examine the evolution of these targets over time, with a focus on whether they have ratcheted-up and how their credibility has changed; and (3) to assess their effectiveness in accelerating the growth of renewable technologies. Analysing G20 countries, which account for a substantial share of global energy consumption and greenhouse gas emissions, the study provides critical insights into the relationship between target-setting and energy transition outcomes, as well as the feasibility of the Paris climate goals. Preliminary findings reveal that G20 countries’ national targets have consistently lacked credibility in driving renewable energy growth, with most targets either significantly underachieved or overachieved. While targets have generally ratcheted up over time, their progression largely follows the evolving trends and rates of renewable energy development within the countries. In many cases, targets align with these evolutions rather than altering the trends or accelerating rates beyond their respective observed trajectories. Notably, however, targets set after the Paris Agreement deviate from this pattern in many G20 countries, aiming for significantly faster and more ambitious renewable energy developments. This is likely due to the effects of the ratchet-up mechanism of the agreement, which altered the logic of target-setting. On the other hand, these newer targets may demonstrate even lower credibility than earlier targets, as they are likely to be underachieved to a greater extent. This is because these increasingly ambitious targets have not effectively accelerated the growth of renewable technologies in the last decade. In other words, the changing logic of target-setting has progressively undermined their credibility and consequently widened the implementation gap, making the newer targets less feasible. This study advances the understanding of the ratchet-up mechanism and the implementation gap in policy efforts to mitigate climate change by providing the first large-n quantitative analysis of the evolution and performance of national renewable targets. The findings challenge the assumption that more ambitious targets necessarily lead to faster transitions and offer critical insights into the limitations of target-setting and its implications for achieving the Paris climate goals.