Climate Economics

The Numbers We've Been Avoiding: What Adrien Bilal's Research Tells Us and What We're Building at Cityzeen

If you've been following climate economics in the news lately, you've probably already encountered Adrien Bilal's work without realizing it. He's the quiet force behind some of the most unsettling and important numbers to come out of academic economics in the last decade. The kind of numbers that make newspaper editors pause, that get cited in Nature and the New York Times in the same week, and that have a way of reframing conversations that most institutions would rather keep comfortable.

Bilal is an Assistant Professor of Economics at Stanford University. He trained at Princeton, did a postdoc at the University of Chicago, spent time at Harvard, and is now one of the most-watched young economists in the world. Le Cercle des économistes and Le Monde just named him Meilleur Jeune Économiste 2026, Best Young Economist of the Year. It's a deserved recognition. But if you've been reading carefully, it also feels inevitable.

Here's why.

The Finding That Changed the Conversation: Climate Damages Are Six Times Larger Than We Thought

The headline number from Bilal's work is this: the macroeconomic damages from climate change are approximately six times larger than previously estimated.

Let that sit for a moment.

For years, the dominant models used by economists, policymakers, and financial institutions had been working from a set of damage functions — mathematical relationships that translate temperature increases into economic losses. These models were the foundation of climate policy negotiations, carbon pricing debates, and corporate risk assessments. They were also, according to Bilal's research, dramatically underestimating the problem.

In his paper "The Macroeconomic Impact of Climate Change: Global vs. Local Temperature", Bilal and his co-author Diego Känzig identify a fundamental flaw in how previous models were built. Earlier studies typically relied on variations in local temperature to estimate economic damages — essentially asking: when it gets hotter in a specific place, what happens to economic output there? The answer, reassuringly, seemed manageable.

But Bilal and Känzig argue this is the wrong question. What actually matters is global temperature — the aggregate warming of the planet — and when you use that as your benchmark, the picture changes completely. Global temperature shocks are correlated across regions in a way that local shocks aren't. They affect supply chains, agricultural systems, energy grids, and migration patterns simultaneously. The damages don't just add up — they compound.

The result: a damage estimate roughly six times higher than what most integrated assessment models had been producing. This isn't a rounding error. It's a structural recalibration of how we understand climate risk.

The paper landed in the Quarterly Journal of Economics — one of the most prestigious journals in the field — and the media response was immediate and global. Bloomberg, The Economist, Le Monde, The Guardian, the New York Times, Nature. That breadth of coverage isn't typical for academic economics. It signals that the finding crossed a threshold: it wasn't just academically significant, it was too important to stay inside a journal.

Turning Temperature Into Death: The Mortality Question

If the GDP damage paper was unsettling, the mortality work is harder still.

In "Global Temperature and Global Mortality", Bilal along with co-authors Diego Känzig and Karol Lisiecki asks a question that economists have historically been reluctant to confront directly: how many people die because the planet is getting warmer?

This isn't a hypothetical. Every fraction of a degree of warming translates, statistically, into changes in mortality rates — from heat stress, from the spread of disease, from the collapse of agricultural systems, from the cascading effects on healthcare infrastructure in already-stressed regions. The question is how to measure it rigorously, at scale, and in a way that captures the full chain of causation rather than just the most visible links.

What makes Bilal's approach distinctive is its macroeconomic framing. Rather than studying individual heat events or localized mortality spikes, he and his co-authors build models that connect global temperature dynamics to mortality outcomes across economies and time horizons. The goal isn't just to document that warming kills people — we already knew that. The goal is to quantify the relationship precisely enough that it can inform policy, pricing, and decision-making at the institutional level.

This work is still in progress, which makes it worth watching. The preliminary results are already reshaping how economists think about the "social cost of carbon" — the number that underlies most climate policy calculations worldwide.

Can We Afford to Decarbonize? He Says Yes and Here's the Math

One of the most politically charged questions in climate economics is whether aggressive decarbonization is economically viable, or whether the cure is as damaging as the disease. It's a question that fossil fuel interests have spent decades muddying with selective statistics.

Bilal's paper "Does Unilateral Decarbonization Pay For Itself?" (with Diego Känzig) addresses this directly. The finding, published in the American Economic Association Papers and Proceedings, is striking: unilateral decarbonization — meaning one country or region acting alone, without waiting for global coordination — can be economically self-justifying when you properly account for the full scope of climate damages avoided.

This matters enormously for policy. The standard objection to ambitious climate action is the free-rider problem: why should we bear the costs if others won't? Bilal's work provides a serious economic counterargument — not a moral one, but a financial one. The damages you avoid by acting, even alone, can outweigh the costs of acting. The math, when done correctly, favors speed.

The Geography of Inequality: Where You Live Shapes Everything

Not all of Bilal's work is about climate. Some of his most influential research is about space — literally, the economic consequences of where people are located.

His paper "Location as an Asset", published in Econometrica with co-author Esteban Rossi-Hansberg, makes a deceptively simple but profound argument: location is not just a backdrop for economic life, it is itself an economic resource — one that workers and firms hold, trade, and lose access to.

Think about what this means in practice. Two workers with identical skills, education, and experience can have dramatically different economic outcomes simply because of where they live — access to labor markets, proximity to productive firms, quality of local public goods. Location isn't neutral. It's an asset that some people inherit, some people acquire, and many people can't afford.

This framing has significant implications for how we think about inequality, urban policy, and economic mobility. It also sets up a direct line to the climate question: if location is an asset, then climate-driven changes to livability — flooding, extreme heat, air quality degradation — are not just environmental problems. They are acts of asset destruction, falling most heavily on those with the fewest resources to relocate or adapt.

Outsourcing, Inequality, and the Hollowing Out of Local Economies

In "Outsourcing, Inequality and Aggregate Output" (with Hernán Lhuillier), forthcoming in the Journal of Political Economy, Bilal turns to a different but related question: what happens to an economy when firms increasingly outsource their lower-wage functions?

The answer, documented rigorously, is that outsourcing increases inequality — not just because it suppresses wages at the bottom, but because it changes the structure of firms in ways that reduce aggregate output over time. The gains from outsourcing that accrue to shareholders are real, but they are purchased at the cost of broader economic health. This is the kind of finding that cuts across the usual political alignments: it's not ideological, it's mechanical.

What connects this to the rest of Bilal's work is the underlying concern with distribution — who bears the costs of economic transformation, and whether the aggregate numbers we use to measure progress are hiding the damage at the margins.

The Space Between Research and Reality

Here is what all of Bilal's work, taken together, tells us:

Climate change is not a future problem being slowly priced in. It is a present structural force already embedded in mortality rates, already reshaping the economic value of locations, already compounding at a rate that our models have been systematically underestimating. The damages are larger than we thought. They fall unevenly. And the cost of inaction, properly calculated, exceeds the cost of acting — even acting alone.

This is the scientific and economic consensus, built carefully, paper by paper, by researchers like Bilal. It is rigorous, peer-reviewed, and now impossible to ignore.

And yet — there is a gap.

The gap is between what the research tells us and what actually happens in the rooms where decisions get made. Budget meetings in city halls. Infrastructure planning sessions. Urban development committees. The people in those rooms are not reading Econometrica. They are dealing with procurement deadlines, political constraints, and datasets that were never designed to answer the questions climate change is now forcing on them.

That gap — between the macro clarity of the research and the operational fog at the city level — is exactly where Cityzeen works.

What We're Building at Cityzeen: Turning Research Into Action

At Cityzeen, we start from the same premise that runs through all of Bilal's work: climate risk is local, spatial, and unevenly distributed — and the institutions best positioned to respond to it are cities.

Not national governments, who move slowly and abstractly. Not financial markets, which price risk in aggregate and miss the granularity. Cities. Because cities are where infrastructure ages and fails. Where neighborhoods flood or overheat. Where the people most exposed to climate risk actually live. And where decisions about adaptation, investment, and resilience get made — or don't get made — every day.

What Bilal's research quantifies at the macro level, CityZeen makes actionable at the local level.

We build tools that translate climate exposure into the language that city governments actually use: risk maps that sit on top of urban infrastructure data, dashboards that connect climate projections to budget planning cycles, decision frameworks that help municipalities prioritize where to act, how fast, and with what resources.

When Bilal shows that climate damages are six times larger than previously estimated, the implication for cities is immediate and practical: your current risk assessments are almost certainly wrong. The infrastructure you think is safe may not be. The neighborhoods you've deprioritized may be the most exposed. The investment horizon you're planning against is too long.

CityZeen exists to help cities close that gap — not in a journal, but in a meeting, in a planning document, in a procurement decision.

When Bilal shows that location is an asset, and that climate degrades that asset unevenly, the implication is equally clear: the cities that adapt fastest will protect the economic value of their most vulnerable neighborhoods. The ones that don't will watch that value erode — and with it, the tax base, the social cohesion, and the political stability that urban governance depends on.

This is not a distant scenario. It is already happening, in cities across Europe, Asia, and the Global South. The research is ahead of the institutions. CityZeen's job is to close that distance.

We Are, in the Deepest Sense, Aligned

Adrien Bilal's work is a call to recalibrate — to take seriously numbers that are uncomfortable, to stop underestimating a problem because the correct estimate is too large to act on without changing everything.

CityZeen is an answer to that call, built for the institutions that have both the mandate and the proximity to do something about it.

The science is getting sharper. The tools are getting better. The cities that move now — armed with the right data, the right frameworks, and the right partners — will be the ones that come out of this transition stronger, more resilient, and better positioned to offer their residents the thing Bilal's research ultimately argues for: a place that is worth living in, for a long time to come.

That is what we are building. And the research couldn't be clearer about why it matters. 

CityZeen works with cities and local governments to translate climate risk into operational decisions. If you're working on urban resilience, infrastructure planning, or climate adaptation we'd like to talk.

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