Conference Agenda

The econometric studies built on the STIRPAT framework clearly show that greenhouse gas emissions respond much more strongly to changes in the population size than to changes in per capita production. Therefore, human population is one the major drivers of carbon emissions but nevertheless its specific role

in determining emissions has never been specifically accounted for in the analysis of climate policy. Moreover, since emissions determine carbon concentrations which represent an important source of disutility, population plays a key role in determining the effectiveness of climate policy also through preferences.

In order to understand whether and how the dependence of emissions on the population size affects our

conclusions regarding mitigation, we integrate a global integrated assessment model of climate-economy with the STIRPAT formulation. In particular, we allow population to act as an independent factor affecting emissions in a non-proportional manner and utility to negatively depend on carbon concentrations.

In this setting, we show that emissions, the temperature increase and the cost of climate mitigation are all much larger than what traditionally believed, and thus more abatement efforts and earlier interventions are needed in order to effectively reduce the economic impacts of climate change. Therefore, by underestimating the detrimental environmental consequences of anthropogenic activity, extant literature

provides a substantially biased analysis of the importance of climate policy, which instead requires more costly and urgent mitigation measures to achieve the mid-of-century objectives set by international climate agreements

Dynamic social norms have recently emerged as a promising approach to promoting energy-saving behavior. While static norms emphasize prevalent behaviors, dynamic norms focus on behavioral change over time. However, existing studies predominantly examine behavioral outcomes, neglecting the processes and trade-offs underlying responses to norm information. Furthermore, the role of the factors driving dynamic norms remains unexplored. This study employs a discrete choice experiment (DCE) and a randomized control trial (RCT) to address these gaps, finding that dynamic norms driven by climate change enhance preferences for electricity savings, whereas those driven by energy supply security do not. Further analysis of effect heterogeneity highlights the pivotal role of individuals' ascription of responsibility.

This paper examines the optimal energy transition to achieve net-zero emissions, integrating carbon dioxide removal (CDR) and mitigation strategies within a dynamic welfare-maximization framework. Our model incorporates three key constraints: (1) a carbon budget limiting cumulative net CO2 emissions to meet climate targets, (2) hard-to-abate emissions from sectors lacking viable decarbonization technologies, and (3) limited land availability for nature-based CDR, such as afforestation. We distinguish between nature-based CDR methods with leakage risks and technological CDR, which are not yet mature and yield high marginal costs but store CO2 almost permanently. Our analysis identifies the conditions under which CDR can complement mitigation without deterring abatement efforts. We show that, while both CDR methods delay carbon budget exhaustion and facilitate smoother transitions to net-zero emission in the medium run, they may lead to mitigation deterrence in the long term. Specifically, at the steady state, when technological CDR becomes sufficiently affordable, abatement efforts may be discouraged, with technological CDR offsetting both incompressible and potentially abatable emissions. Our findings reveal that the social cost of carbon remains at least constant and can even continue to rise after the carbon budget is exhausted, discouraging the reintroduction of fossil fuels and increasing reliance on technological offsetting and abatement, rather than on nature-based CDR.

This paper utilizes state of the art modeled scenarios to examine the effect of voluntary corporate climate commitments on near- and mid-century climate mitigation goals. We find that current voluntary initiatives, even if scaled, are largely insufficient to achieve goals aligned with the Paris Agreement. However, efforts to drastically increase near-term emission reductions to meet 2030 targets and incorporating emissions reductions from forests and other land-based mitigation opportunities (aka “Forests+”), substantially increase the likelihood of staying well below 2C. In all cases, when Forests+ are included in corporate commitment scenarios, aggregated abatement increases and costs decline. Addressing notable concerns, we find that each ton of Forests+ credits leads to no more than 0.5 tons of additional energy emissions (e.g. due to additional sequestration); and that trading ratios could mitigate potential leakage or impermanence issues. Therefore, immediate action on Forests+ activities that benefit people, nature, and climate, should be prioritized.