Search

The IPCC's 6th assessment report (AR6) has provided a wide range of variables and scenarios that meet climate targets of varying ambition. Many variables reported in the AR6 affect human welfare through climate change and mitigation, including but not limited to economic output, the natural environment, human health, and food and energy supply. In some of these dimensions, trade-offs exist between better performance in welfare-relevant dimensions and reaching more ambitious climate targets. Here, we apply recent advances in the theoretical multidimensional measurement of welfare, like the Human Development Index, to the AR6 database. The welfare metric is based on a welfare function approach, simple to apply, and intuitive. We apply a range of specifications of the welfare metric, aiming to derive robust rankings of climate policy targets that perform best in terms of the multidimensional welfare index. Across a large range of weights on welfare-relevant variables, we find that lower temperature is associated with higher welfare in 2100 unless there is a high weight on food supply. [ABSTRACT FROM AUTHOR]

Climate policy is often described by economists as an intertemporal consumption trade-off: consume all you want today and face climate damages in the future, or sacrifice consumption today to implement costly climate policies that will bring future benefits through avoided climate damages. If one assumes enduring technological progress, a society that is more averse to intertemporal inequalities should postpone climate policies and let future, richer generations pay more. Growing evidence however suggests that the trade-off is more complex: abrupt, extreme, irreversible changes to the climate may cause discontinuities to socio-economic systems, possibly leading to a sharp decline of human population and consumption per capita. In this paper, we show that, when accounting for a very small risk of catastrophic climate change, it is optimal to pursue stringent climate policies to postpone the catastrophe. Our results conform with the well-known conclusion that tight carbon budgets are preferred when aversion towards inequalities between generations is low. However, by contrast with previous studies, we show that stringent policies are also optimal when inequality aversion is high. The non-monotonicity of the influence of inequality aversion is due to the fact that, for a given investment in abatement, a higher inequality aversion gives a smaller weight to avoided future non-catastrophic damages, but a larger weight to the catastrophic outcome. We also explore the role of population ethics, and show that the size of the optimal carbon budget decreases with the social preference for large populations, although this parameter plays almost no role at extreme levels of inequality aversion. Our result demonstrates that views from opposite sides of the ethical spectrum in terms of inequality aversion converge in terms of climate policy recommendations, warranting immediate climate action. [ABSTRACT FROM AUTHOR]

The saltmarsh carbon storage potential is a key topic in blue carbon research and climate policy. Ecosystem service valuations provide valuable information to policymakers for habitat management and climate change mitigation policies. Yet, only few saltmarsh valuation studies have included the carbon storage service in the UK context. This paper investigates how the public values saltmarsh ecosystem services, focussing on the carbon storage service. We used a choice experiment to elicit the willingness to pay (WTP) of a representative sample of the Scottish public to support interventions that would maintain or improve the provision of these services. Furthermore, we tested the effect of information on individuals' preferences and WTP with a split sample approach where one group received a treatment in the form of additional information. We found that (i) all attributes had a significant influence on individuals' choices; (ii) both groups had, on average, a positive marginal WTP for all presented ecosystem services; (iii) the treated sample had, on average, no significantly different marginal WTP for carbon storage than the control group. This paper adds to the limited literature on the saltmarsh carbon storage ecosystem service and demonstrates a developed nation's public's openness to nature-based climate change mitigation solutions. [Display omitted] • The Scottish public on average prefers saltmarsh management over the status quo. • Providing additional information reduced heterogeneity in WTP for carbon storage. • Most respondents preferred an improvement of all saltmarsh ecosystem services. • Therefore management should focus on both climate change mitigation and adaptation. [ABSTRACT FROM AUTHOR]

In cost-benefit analysis of climate policy there are two main approaches to discounting, each with implications conflicting with our moral intuitions. Thus, discounted utilitarianism implies that we hardly need to protect future generations against climate change, while classical utilitarianism implies that we should reduce our consumption across the board to benefit future generations. The insolubility of the debate derives from the fact that both classical and discounted utilitarianism permit only a single discount rate for all consequences occurring in the same future year, while our intuitions clearly do distinguish between consequences, depending on whether we cause adverse effects on other people's interests and violate their rights. Most people share the moral intuition that we ought to refrain from harming others, and ought to compensate them if we were unable to prevent harm. To regain a reflective equilibrium between such deontological intuitions and economic theory there is a need to accept different discount rates for different situations: a zero consumption discount rate in the case of cost-benefit analysis of measures to prevent wrongful harm to future generations, and standard discounting in all other cases. Applying a zero consumption discount rate means that future generations are automatically largely compensated for climate damage that remains unmitigated. [ABSTRACT FROM AUTHOR]

• Optimal climate change mitigation mostly focused representative agent framework. • Incomplete insurance markets adds realism and new mechanism for welfare. • Poorer households prefer stronger mitigation policies even absent redistribution. • Redistribution provides extra insurance. • Representative agent framework likely to underestimate welfare impacts of mitigation. Policy makers concerned with setting optimal values for carbon instruments to address climate change externalities often employ integrated assessment models (IAMs). In the past, these tools have relied on representative agent assumptions or other restrictive behaviour and welfare aggregations. However, there is an important trend in the economics of climate change towards including a greater degree of heterogeneity. In the face of global inequality and significant vulnerability of asset poor households, we relax the complete markets assumption and introduce a realistic degree of global household inequality. In contrast to the representative agent framework, we find that a household's position on the global wealth distribution predicts the identity of their most-preferred carbon price. Specifically, poor agents prefer strong public action against climate change to mitigate the risk for which they are implicitly more vulnerable. We find that the carbon tax fills the role of insurance, reducing the volatility of future welfare. It is this role that drives the wedge between rich and poor households' policy preferences, even in the absence of redistribution. Taking into account the risk channel, we derive an optimal tax value four times larger than standard estimates from representative agent models. [ABSTRACT FROM AUTHOR]

The uptake of actions to mitigate climate change at the household level might crowd out subsequent policy at the national level, which is problematic because national policy often has a larger mitigation potential than individual household measures. This study analyses crowding out between the uptake of low-cost actions and the support for national climate change policy in the agricultural sector. In the experimental set-up, survey respondents were primed to think about the implementation of low-cost mitigation practices and subsequently asked to express support for national mitigation policy. The results show a crowding-out effect between individual mitigation measures and support for national policy. Individuals with high levels of worry show a stronger crowding out effect. This study contributes to building understanding of when and why crowding out occurs in order to help frame and communicate future climate change policy. • Individual mitigation measures crowd out support for national climate change policy. • Crowding out is stronger within the climate change domain than biodiversity domain. • Individuals with high levels of worry show a stronger crowding out effect. [ABSTRACT FROM AUTHOR]

Abstract: Plural values contribute to multiple arrays of expressed preferences. Conventionally, preference convergence toward consensus among initially disagreeing decision makers is understood in terms of diminishing value differences. A cogent account of consensual decision that respects non-diminishing value plurality is lacking. Instead there is a theoretic expectation for categorical consistency between subjective values and expressed preferences. Valuing agents in social interaction are expected to indicate identical preference orderings only if they hold correspondingly identical categories of values. This expectation precludes meaningful conceptualization of preference convergence under divisive normative dispositions. An alternative framework is proposed and illustrated by results from a designed deliberative forum on Australia''s climate change policy. Data were analyzed based on Q methodology. Results show that small-group deliberations enabled effective communication between distinctive subjective positions and broadened understandings between individuals. While a consensual decision gained progress, no identified value discourse diminished below a significant degree. Observed changes in values did not run parallel to the converging preferences, suggesting a decline in value-preference consistency. These changes nonetheless are amenable to the principle of value pluralism. An alternative rationality concept is needed to account for this moral ideal within economics. [Copyright &y& Elsevier]