Thomas Piketty’s views on the climate transition

In an interview with Nabil Wakim and Cécile Cazenave on the Le Monde website, the French economist explains that protecting the planet from climate change cannot be achieved without reducing inequality.

 

Thomas Piketty: ‘To succeed in the climate transition, we must redistribute wealth differently’

The current economic system is often criticized for its inability to implement effective policies to combat climate change. Should we transform capitalism to reduce our greenhouse gas emissions? How can we envision a different economic system, one that is suited to the 21st century and the preservation of resources? Thomas Piketty is an economist and the author of numerous works on wealth inequality, including Le Capital au XXIe siècle (Capital in the Twenty-First Century, 2013). A collection of his columns for Le Monde was published in 2025 under the title Vers le socialisme écologique (“Toward Environmental Socialism”).

In a column for Le Monde, you wrote that it is “impossible to seriously fight climate change without a profound redistribution of wealth, both within countries and internationally. Those who claim otherwise are lying to the world.” Why is there a link between climate change and social inequality?

First, it is important to keep in mind that all major political, institutional and social transformations over the past two centuries have taken place alongside a reduction in inequality and a movement toward greater equality. Climate change, the great challenge of this century, will be no exception to this rule for a simple reason: As soon as you undertake major transformations, they have consequences for how the burden is shared. And the only way to achieve these transformations is to do so in a fair way.

We create justice standards that make this new society and its institutions acceptable to the greatest number of people. All of this is interconnected and yet is sorely lacking in public debate. Reading reports from the Intergovernmental Panel on Climate Change (IPCC), you learn a great deal, but the role of social class is glaringly overlooked. Sometimes, the reports also lean a little too much toward technophilia – betting on solutions like carbon capture, which are not only hypothetical but potentially dangerous. If we want these transformations to succeed, issues of inequality and class need to be incorporated into the IPCC’s reports.

Research conducted by several economists has shown that social inequality mirrors inequality in greenhouse gas emissions. The wealthier people are, the more CO2 they emit.

This is true on a global scale – emissions in countries of the Global South are generally very low. But it is also true within single countries, whether in Europe or elsewhere in the world. In concrete terms, the poorest 50% of people in France or across Europe each emit approximately 4 to 5 metric tons of CO2 per year. The goal is to reach 2 metric tons by 2050, so it is clear that we are not entirely missing the mark. By contrast, if you look at the wealthiest 10% or even the top 1%, they emit between 50 and 100 metric tons of carbon dioxide per person. In that case, we are completely o! track when it comes to climate targets. If we look at international comparisons, the lowest-emitting 50% in France or in Europe will emit less than the top 10% or even 5% of emitters in India. As a result, when considering how to redistribute wealth and create acceptable solutions, this must be done within countries as much as between them. Otherwise, working class and middle-class people, including those in the Global South, will reject these changes.

One could, however, argue the opposite, by saying that there is not enough time to reduce inequalities and fight global warming simultaneously. It is better to have a planet with injustices than an uninhabitable planet.

Except that we are not making any progress! That is why we must seek alternative solutions. I would add – because I want to send an optimistic message in my work – that, historically, we succeeded in reducing inequalities while also building the Sécurité Sociale [France’s national health and welfare system] and public services, moving toward a less market-driven economy.

The reduction of inequalities over the course of the 20th century was considerable, albeit it did not go as far as hoped. When I talk about environmental socialism for the 21st century, I would like us to take it much further.

The social-democratic revolution of the 20th century was an immense transformation. When a society shifted from a situation in which social security contributions, taxes and other compulsory levies accounted for less than 10% of national income before World War I to 40%-50% today, it was no longer the same form of capitalism at all.

If, before 1914, someone had told financial or economic elites that half of national income would eventually be taxed, they would have dismissed it as communism and predicted economic collapse. Yet not only did it not collapse, but those very taxes are what made it possible to achieve a significant level of prosperity, with whole sectors of the economy created outside the logic of profit. Education and health care came to represent nearly 20%-25% of wealth creation.

That was how inequality was reduced and new ways of organizing the economy were invented. When discussing future prospects, it is essential to build on that achievement. We have grown used to this transformation! It did not happen on its own – it was the result of a political and social struggle. Let’s look at how it worked to go further and consider changes of a similar scale.

These transformations generated prosperity and growth, while also leading to greater economic activity. Isn’t there a risk that reducing inequality could result in even higher greenhouse gas emissions?

In fact, the reduction of inequalities during the 20th century happened in part through the transformation of economic sectors. When you increase the provision of education and healthcare services, you still emit far less carbon than when you manufacture cement, iPhones or computers. This requires a reorientation of the very type of economic activity.

But here, too, that shift has already begun to occur. The sectors that expanded in the 20th century were not just those related to concrete or energy. They also included social sectors, which will need to grow much more in the future. Today, education and health care account for approximately 20% to 25% of employment and economic activity, but perhaps they should reach 40% to 50% by the end of the 21st century. The same applies to energy – albeit in drastically renewed forms – with a constant focus on the material footprint.

Decoupling economic growth from carbon emissions is only possible if we completely rethink the sectors in which human activity takes place. If, in the end, we still have the same sectors producing ever more by using ever more materials, you can reduce inequality as much as you want; it will have no effect.

But what makes it possible to fund the social model you are talking about is, in fact, production growth. If everyone works in education or health care, who will fund those sectors?

That’s a surprising question! In that case, who funds the other sectors? Why should education and health care be financed by the material production of concrete, and not the other way around? Because you need energy and concrete first to build roads, schools, buildings and so on.

But we already have those! We absolutely do not need to continue accumulating concrete, building roads, airports, buildings and so on at the same pace. If our population were about to increase 10-fold, that would be another matter. But that is not the case – the population is stabilizing, even decreasing. So, there is no need to keep accumulating concrete, cars, roads, computers and so on.

That’s the case in France, but not necessarily in countries in the Global South. Right?

Of course, I am referring to countries that have already reached the highest standards of living currently observed on the planet. In these situations, there is the greatest need for health care, education and access to culture. Obviously, these activities also have a carbon footprint, and efforts must be made to reduce it.

However, we need to move away from the idea that education and health care must be funded by construction or by material activities. No, these are themselves sources of wealth creation. We can easily imagine a society in which 99% of the population works in these cultural services while 1% oversees the machines that produce the material goods we need, with a carbon footprint and a material footprint much lower than what we have today.

Precisely, for this transformation, we need factories and energy to keep them running, and we need to produce material goods.

I’m not saying we no longer need houses and roads. What I mean is that we do not need to increase the number of buildings in France, to build at the same pace as over the past century, to once again cover France with highways and airports. That does not seem either reasonable or essential.

Unless, of course, we adopt an economic logic that insists we need an excessive number of data centers to run artificial intelligence. That would push us to build nuclear power plants, seek out other energy sources and embark on a new wave of material accumulation. But it is far from certain that these needs should be our top priority! This is the very question we need to start from, and then adapt our organization accordingly.

The idea of a more frugal society is not necessarily appealing to everyone. Many people welcome the construction of an Amazon warehouse or the rollout of 5G technology. There is no broad political consensus on what we should be willing to give up.

All of that is possible if you create more jobs in hospitals, schools and public transportation – areas where needs are widely recognized. But that requires putting inequality at the center. That means ensuring that people earning €1,000 or €2,000 per month do not feel like their standard of living is being sacrificed.

The effort has to start at the very top. If billionaires and multimillionaires – whose numbers have grown sharply over the past two decades – are not asked to contribute, how can we expect executives and middle earners to do so? Ultimately, though, it will not be enough to rely solely on the wealthiest.

It will be necessary to compress the entire income scale. A ratio of one to five, or even one to three, between the lowest and highest incomes could be a realistic target. Once you accept this kind of approach, it becomes possible for people with lower incomes to avoid bearing the cost of the transition. On the other hand, if you pretend that the issue of inequality does not exist and that everyone will adapt, you will be doing something deeply unfair to those who lack the means, and opposition will become insurmountable.

In practical terms, what could that look like?

First, we need to look at what has worked in the past. The reduction of inequality in the 20th century was achieved not only through the Sécurité Sociale but also through highly progressive taxes on income and wealth, particularly on inheritances. If you look at a country like the United States between 1930 and 1980, the highest income tax rate averaged over 80%. And clearly, that did not destroy the American economy.

This simply led to a narrowing of very large income gaps – in other words, incomes above a certain threshold disappeared, because that is  the primary effect of such highly progressive taxation systems. This helped compress the overall scale of both income and wealth, and ultimately left more income for lower wages.

Did that hinder economic development? In fact, no. On the contrary, it was a period of peak prosperity, during which the productivity gap with the rest of the world was at its highest point in history, for the following reason: The secret to collective prosperity is education and a high level of productivity, rather than vast income disparities.

To move forward, we need to build on that and go even further. One of the limits of the income tax is that the wealthiest individuals can avoid it by reporting very low income compared to their total wealth. If the richest billionaires have income that represents only an infinitesimal percentage of their fortune, you could tax income at 80%, but that would not get you very far.

That is why we need a progressive wealth tax that does not allow for any exceptions. This would first bring in considerable revenue: In France, the 500 largest fortunes together represent more than €1 trillion. Ten years ago, it was barely €200 billion! So a 10% tax on that increase in wealth would generate €100 billion, which is much more than all the deficits currently being debated in Parliament. We could also go much further than a 10% tax on that increase in wealth.

How can we ensure that the money collected through taxes will be invested in the climate transition?

This provides resources to invest in transportation, energy infrastructure and building renovation. The amounts required for this transformation are enormous.

We also need to move away from the idea that countries will never succeed on their own, and that the resistance of billionaires and the system of globalization make all of this impossible. In 2024, for example, Brazil tried to push for a global tax on billionaires within the G20. When I raised this idea in 2013 in Le Capital au XXIe siècle, many people said to me: “But how can you imagine such a thing?”

The fact that these issues are now being discussed at the G20, at the initiative of a country from the Global South, indicates that things are changing. It is also important to recognize that the question of funding for climate reparations has become a central concern in international discussions. As a result, countries from the Global South are increasingly raising the issue of tax justice for billionaires, in connection with funding for damages caused by climate change.

In France, green candidate Yannick Jadot advocated for a wealth tax to fund the transition during the 2022 presidential election, but he won less than 5% of the vote. It is not clear whether this idea is very popular.

Green parties have never managed to make social issues and reducing inequality at the heart of the debate. When Yannick Jadot proposed a climate solidarity wealth tax, it was modest and would have had little impact. The rhetoric simply did not measure up in terms of the sums that would need to be raised, the reduction of inequality or the compression of incomes required.

In our book Une histoire du conflit politique (A History of Political Conflict, 2023), written with Julia Cagé, we focused on a segment of the electorate that may seem somewhat secondary but offers a useful comparison: the vote for Trotskyist parties (such as Lutte Ouvrière, Ligue Communiste Révolutionnaire, Nouveau Parti Anticapitaliste). In the French presidential election, this vote has historically accounted for between 3%  and 5% of the ballots cast, roughly the same level of support as green candidates.

What is striking is that votes for Jadot were urban and came predominantly from the most affluent areas. The higher the average income in a municipality, the better the score for the Green candidate. In contrast, Trotskyist votes came mainly from rural areas. These votes were concentrated in small towns and decreased sharply as the wealth of the municipality increased.

If you take a step back, you might think that these two political groups have fairly similar rhetoric when it comes to denouncing extractivist capitalism. But they approach it in very different ways. On one side, they talk about class struggle, with wealth distribution at the heart of their message. On the other hand, that is less the case – and that’s how voters perceive it.

I am not giving this example to idealize parties like Lutte Ouvrière but rather to show that voters can distinguish between different political messages. If Green parties do not radically change their rhetoric on inequalities and social classes, they will struggle to convince other segments of the electorate.

But shouldn’t there also be concrete measures that improve people’s lives in the short term? Otherwise, the transition can seem like a distant and theoretical promise.

Of course, we need positive measures that spark the imagination. We need free public transportation, the first kilowatt-hours of energy provided for free and then the others priced 10 times higher than they are now. We need measures that clearly offer something tangible to a whole segment of the population that, deep down, is willing to join in this transformation.

To achieve this, people must not only consider what it will cost them, but also how it will positively change their way of life. I am not claiming that it is easy; I am simply saying that I do not really see any other solutions.

What still gives you hope, even though this period is marked more by setbacks on the issue?

One of the things that makes me think things are not set in stone is that the mix of nationalism and liberalism currently in power, especially with Donald Trump, will not solve the social and environmental challenges we face. Ultimately, voters will send these experiments back into opposition, and we will have to try new approaches. I believe that the environmental socialism I am describing is not easy to implement, that it will take time, but that we will revisit it because the other solutions – nationalism or liberal logic – will not solve the challenges we face today.

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