The Carbon Content of Billionaire Wealth: Composition, Concentration, and Taxation

While increasing evidence highlights large disparities in emissions between and within countries, detailed individual-level data on emissions portfolios remain scarce.

In this paper, Krystian Bua, Matteo Coronese, Francesco Lamperti, Chiara Marino, Elisa Palagi and Andrea Roventini construct a novel dataset linking the asset holdings of the world’s 501 richest billionaires to greenhouse-gas emissions. Using wealth composition data from the Bloomberg Billionaires Index together with firm-level emissions and market data, they estimate individual ownership-based carbon footprints and analyze their distribution across assets, sectors, and wealth groups. The study also evaluates a new progressive carbon wealth tax and compares it with conventional wealth and carbon taxation schemes.

KEY FINDINGS

• Every USD 1 million held by the top 501 billionaires is associated with more than 65 tCO₂e per year – about 10 times the annual carbon footprint of the average person –  under the ownership-based accounting framework.
• Emissions are even more concentrated than wealth: around 50 billionaires account for roughly three-quarters of total emissions in the sample.
• Publicly traded equity holdings are the main source of billionaire emissions, with investments in Basic Materials, Industrials, and Utilities playing a particularly important role.
• Emission intensity is key: 97% of the variance in log emissions is explained by intensity differences, suggesting that scale effects play a limited role and carbon footprints are almost entirely driven by investment choices.
• The highest-emitting billionaires derive between 44% and 66% of their portfolio emissions from investments in hard-to-abate sectors.
• The top 501 billionaires collectively represent a striking concentration of both wealth and ownership-based emissions, with the top 0.00001% of the global population owning more than 1% of each.
• Simulations suggest that a progressive carbon wealth tax could raise approximately USD 151 billion per year while simultaneously increasing tax progressivity, targeting high-emission activities, and mobilizing resources for a sustainable and equitable transition.

AUTHORS:

• Krystian Bua, Institute of Economics and L’EMbeDS, Scuola Superiore Sant’Anna, Pisa, Italy
• Matteo Coronese, Institute of Economics and L’EMbeDS, Scuola Superiore Sant’Anna, Pisa, Italy, RFF-CMCC European Institute for Economics and the Environment, Milan, Italy
• Francesco Lamperti, Institute of Economics and L’EMbeDS, Scuola Superiore Sant’Anna, Pisa, Italy, CMCC Foundation—Euro-Mediterranean Center on Climate Change, Lecce, Italy
• Chiara Marino, Institute of Economics and L’EMbeDS, Scuola Superiore Sant’Anna, Pisa, Italy
• Elisa Palagi, Institute of Economics and L’EMbeDS, Scuola Superiore Sant’Anna, Pisa, Italy
• Andrea Roventini, Institute of Economics and L’EMbeDS, Scuola Superiore Sant’Anna, Pisa, Italy, OFCE Sciences Po, Sophia-Antipolis, France