Conference Agenda

It is widely acknowledged that wealth-based indicators by the two authorities (groups of the World Bank and the United Nations) encounter problems in showing significant discrepancies in empirical estimates, disregarding the equivalence of their theoretical basis. Most studies use observed market prices for shadow prices and past datasets for quantities of various capital components in wealth accounting. Instead, we employ our integrated assessment model (IAM) to generate quantities and shadow prices up to 2150. Our IAM endogenously generates utility flow determined by per capita consumption over 10-year time intervals, enabling us to compute the growth rate of the discounted sum of utility (i.e., social welfare) and per capita consumption. The model enables us to use consistently forward-looking shadow prices and quantities to calculate wealth components across the wealth-based indicators. We compared our rates with those of the indicators to show which are closest to social welfare and per capita consumption.

Achieving climate-neutrality is a central goal of European climate policy. Member States have submitted legally binding National Commitments (NCs) for decarbonization through their National Energy and Climate Plans (NECPs). However, achieving NCs efficiently, in tailored ways to national contexts, while considering policy preferences and uncertainties remains a challenge. This study addresses this gap by developing a novel operational framework for the refinement of the NCs through prioritizing investments in key decarbonization measures. We present a Decision Support System uniquely combining: high-granular simulations of the Greek energy system in the Low Emissions Analysis Platform (LEAP), under different NECP-based measures; and the Fuzzy Analytic Hierarchic Process (AHP) and the Fuzzy Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) Multicriteria Analysis techniques. The Fuzzy AHP is used to weight different energy, emissions, time, trade and costs considerations (criteria), accounting for preference uncertainty. The Fuzzy TOPSIS offers then a ranking of the different simulated measures, accounting for data and/or modelling uncertainty. The resulted set of measures includes almost half of the initial NECP-based strategies, and can lead to decarbonization faster, cheaper, and at lower total emissions over the planning horizon.

Affluence is broadly associated with greater well-being, across all income levels, and also greater environmental impacts. Many impacts are currently unsustainable. This poses a central question in environmental economics: can economic growth be decoupled from environmental impacts? Some argue that growth and affluence drive innovations which are key to reducing environmental impacts while increasing well-being (“green growth”). Others argue that holding constant or decreasing affluence is necessary to make environmental impacts sustainable (“de-growth”). A third group argues that policies should focus on reducing environmental impacts to sustainable levels, agnostic to any effects on growth (“a-growth”). To inform this debate, here we compile and analyze global trends in nine representative anthropogenic environmental impacts and pressures: CO2 and SO2 emissions; energy use; nitrogen, phosphorus and land use for agriculture; material footprint; fisheries catch; and biodiversity loss. The intensities of most impacts (i.e., impact or pressure per dollar gross domestic product (GDP)) are decreasing in most World Bank income groups. Five of nine impacts are decreasing in absolute terms in the high-income group: phosphorus, agricultural land, CO2, SO2, and fisheries. Our results highlight promise and remaining challenges for sustainable economic growth.

The twin crisis of climate change and biosphere degradation is deepening, yet integrated assessment models still treat them as separate problems. This paper extends the latest Dynamic Integrated Climate-Economy (DICE-2023) model to incorporate three Earth system processes highlighted by the Planetary Boundaries framework: climate, biosphere integrity, and land system change. We add a land use sector and a biosphere integrity stock, operationalised through the Biodiversity Intactness Index (BII), to explicitly link the global economy, climate, and biosphere integrity, capturing the key dependencies and reciprocities. The model supports both classical DICE-style cost-benefit analysis and target-constrained analyses that quantify the welfare cost of staying within specified planetary boundaries. Our preliminary results highlight that the next 75--100 years are decisive: population, income, and climate pressures peak in this period, while the biosphere damages inflicted by these pressures are partly irreversible on policy-relevant timescales. Thus, our results call for jointly pricing biosphere degradation alongside climate change. Doing so yields a new shadow price: the social cost of biosphere degradation (SCB). The SCB is of comparable economic importance to the social cost of carbon, motivating early action to protect biosphere integrity alongside climate mitigation.