Human wellbeing is the guiding goal of many public policies, yet its complexity often prevents present measurement and future projections of it. Here, using a global model and a wellbeing measure called Years of Good Life (YoGL), we show how climate change, economy, and social conditions together shape people's long-term wellbeing. We also introduce the ‘wellbeing cost of carbon' metric, which is similar to the social cost of carbon but measures the wellbeing loss due to carbon emissions instead of only economic loss. The results highlight that younger generations pay the highest price unless strong climate action is taken.

Human wellbeing is the ultimate end of sustainable development alongside planetary wellbeing. It relies on complex interactions between natural and social systems, including those between climate change, economic growth, and human mortality. Despite extensive analyses of individual climate impacts, their combined effects on long-term wellbeing are sparsely examined. Using a dynamic systems model of global climate, economy, environment, and society relationships and employing YoGL as an empirical wellbeing indicator, we present wellbeing projections in diverse socioeconomic and climate scenarios, and calculate the loss of human wellbeing due to carbon emissions. In a climate-optimistic scenario, 20-year-old females and males gain 10.4 and 7.5 YoGL, respectively, on average by 2100, while a pessimistic scenario reduces it by 8.5 and 11.3 years. Physical health remains the most restraining driver of long-term human wellbeing, while indirect climate impacts on education and poverty also reduce it by a similar extent in a climate-pessimistic scenario. The younger generations bear a much higher wellbeing cost of carbon unless strong climate action is taken. This study offers a new quantitative, empirically grounded and integrated perspective on climate impacts on human wellbeing, expanding beyond economic damages and the social cost of carbon.

Climate choices today shape our future wellbeing: Strong action boosts ‘good life’ years, inaction takes it away.