Investors Are Pricing In Climate Risk More Than You Think

The Market Has Already Priced In the End of Oil

In 2020, a barrel of West Texas Intermediate crude oil briefly traded at negative $37. That was a pandemic fluke. But something stranger has been happening in the stock market for years, something that predates COVID and will outlast it. Companies that spew carbon have been delivering higher returns to their shareholders. Not in spite of their pollution. Because of it.

This sounds backwards. Climate risk is supposed to be bad for business. Regulators are tightening rules. Consumers are shifting preferences. Investors are signing net zero pledges. So why would dirty companies outperform clean ones? Because investors are demanding a premium to hold those stocks. They are pricing in climate risk more aggressively than most people realize.

The evidence comes from a landmark study by Patrick Bolton and Marcin Kacperczyk, published in the Journal of Finance in 2023. They analyzed 14,400 firms across 77 countries, covering nearly every publicly traded company with meaningful carbon data. What they found upends the conventional wisdom that markets are ignoring climate change (Bolton & Kacperczyk, 2023).

The Carbon Premium Is Real and Global

Bolton and Kacperczyk measured something they call the "carbon premium." This is the extra return that investors demand for holding stocks of companies with high carbon emissions. The logic is simple: if you own a coal company, you are taking on transition risk. Governments might tax your emissions. Customers might boycott your product. Courts might hold you liable for climate damages. Investors want compensation for bearing that risk.

The authors found that this premium exists across all sectors and most countries. Companies in the top quartile of carbon emissions deliver higher stock returns than those in the bottom quartile, after controlling for standard risk factors like size, value, and momentum (Bolton & Kacperczyk, 2023). The effect is not small. A firm with higher emissions growth sees its stock price adjust upward to reflect the risk premium investors demand.

This is not a story about oil companies versus tech firms. The carbon premium shows up within industries. A dirty utility outperforms a clean utility. A carbon intensive manufacturer beats a cleaner competitor in the same sector. The market is making fine grained distinctions.

How the Study Was Done

Bolton and Kacperczyk built a massive dataset. They combined firm level financial data from Compustat with carbon emissions data from Trucost, covering Scope 1 emissions (direct emissions from owned sources) and Scope 2 emissions (indirect emissions from purchased electricity). They tracked emissions levels and year over year growth rates.

The sample runs from 2005 to 2019, spanning 15 years and 77 countries. That includes developed markets like the United States and Japan, emerging markets like China and India, and smaller economies like Kenya and Vietnam. The authors ran cross sectional regressions of stock returns on emissions measures, controlling for market beta, book to market ratio, momentum, and other standard predictors.

The key finding: a one standard deviation increase in emissions growth is associated with a statistically significant increase in annual stock returns. The exact magnitude depends on the specification, but the direction is consistent. Higher emissions mean higher expected returns (Bolton & Kacperczyk, 2023).

Why This Surprised Everyone

Before this paper, many economists believed that climate risk was underpriced. The argument went like this: investors have short time horizons, carbon emissions are externalities, and markets fail to account for long term threats. Bolton and Kacperczyk showed the opposite. Investors are not ignoring climate risk. They are demanding compensation for it.

The mechanism is not about ethics or ESG scores. It is about risk and return. If you own a stock that might lose value due to climate regulation, you want a higher expected return to justify the risk. That higher expected return shows up as a discount on the current stock price. The dirty company's shares trade at a lower price relative to earnings, which means higher subsequent returns for buyers who take the risk.

This is exactly what the data show. Companies with high emissions have lower valuation ratios. Their stocks are cheaper. The higher returns they deliver are not a reward for being bad. They are compensation for being risky.

The Geography of Climate Risk Pricing

Bolton and Kacperczyk found that the carbon premium varies dramatically by country. This is where the story gets interesting.

Rich Countries Price Emissions Levels

In countries with strict climate policies, like members of the European Union, the carbon premium is driven by the level of emissions. Investors penalize firms that are currently dirty, because those firms face immediate regulatory costs. Carbon taxes, emissions trading systems, and clean energy mandates all create direct financial liabilities for high emitters.

Poor Countries Price Emissions Growth

In developing countries with weaker climate policies, the premium is driven by emissions growth. A factory in Vietnam that is rapidly increasing its carbon footprint faces different risks than a factory in Germany doing the same. In Vietnam, the risk is not current regulation but future regulation. Investors are betting that as the country develops, it will eventually impose climate policies. Firms that have built their business models on rising emissions will face painful adjustment costs.

The authors found that the growth based premium is larger in countries with lower economic development, larger energy sectors, and less inclusive political systems (Bolton & Kacperczyk, 2023). This makes sense. In autocracies, policy changes can be sudden and severe. A coal plant built today might be stranded tomorrow if the government decides to align with global climate goals.

The Awareness Effect

The carbon premium has increased over time. Bolton and Kacperczyk show that the relationship between emissions and stock returns strengthened after 2015, the year of the Paris Agreement. It strengthened further after 2018, when the IPCC released its special report on 1.5 degrees Celsius of warming. As public awareness of climate risk has grown, investors have demanded higher compensation for holding carbon intensive stocks (Bolton & Kacperczyk, 2023).

This is not about green sentiment. It is about rational risk assessment. Investors are updating their models based on new information about regulatory and technological change.

What This Means for Your Portfolio

If you are a passive investor who owns the global market, you are already holding carbon risk. The question is whether you are being compensated for it. The Bolton and Kacperczyk study suggests that the market is pricing this risk, but the compensation may not be adequate for all investors.

The Divestment Paradox

Many institutional investors have pledged to divest from fossil fuels. The logic is that selling dirty stocks will lower their prices, raise their cost of capital, and discourage emissions. But Bolton and Kacperczyk's findings suggest a different dynamic. If dirty stocks are already trading at a discount because of risk pricing, then divestment might simply transfer those discounted shares to investors who are less concerned about climate risk. The carbon stays in the air. The risk premium stays in the market.

This does not mean divestment is useless. It might be necessary for ethical reasons or to satisfy stakeholder demands. But the financial case for divestment is weaker if the market has already priced in climate risk.

The Active Manager Opportunity

For active managers, the carbon premium creates an opportunity. If you can identify companies that are high emitters but have credible transition plans, you might earn the risk premium without bearing the full downside. The challenge is that transition plans are cheap talk. Bolton and Kacperczyk's data covers actual emissions, not promises.

A more direct strategy is to overweight stocks in countries with weak climate policies and high emissions growth. The risk premium in those markets is larger, and the probability of policy change is higher. This is a bet on regulatory convergence. It is not for the faint of heart.

What the Research Does Not Prove

Bolton and Kacperczyk's paper is careful. They do not claim that the carbon premium is evidence of market efficiency. They do not claim that all climate risk is priced. They show a statistical relationship between emissions and stock returns, controlling for observable risk factors. There are several open questions.

Does the Premium Reflect Compensation or Mispricing?

One interpretation is that investors are rationally demanding higher returns for holding carbon intensive stocks. Another is that investors have behavioral biases that cause them to overestimate climate risk. If the latter is true, then dirty stocks are undervalued and will eventually revert. The data cannot distinguish between these two explanations.

Is the Premium Stable Over Time?

The study covers 2005 to 2019. The world has changed since then. The Inflation Reduction Act in the United States, the European Green Deal, and the rapid growth of renewable energy have all altered the risk landscape. The carbon premium might be larger today. It might be smaller. Bolton and Kacperczyk's methodology can be updated, but the paper itself is a snapshot.

Does the Premium Include Physical Risk?

Bolton and Kacperczyk focus on transition risk: the risk that climate policy or technology will devalue carbon intensive assets. They do not directly measure physical climate risk: the risk that hurricanes, wildfires, or droughts will damage assets or disrupt supply chains. Physical risk might be priced differently, and it might interact with transition risk in complex ways.

Does the Premium Exist in Private Markets?

The study covers publicly traded firms. Private companies, which account for a large share of global emissions, are not included. If private markets are less transparent and less efficient, the carbon premium might be larger or smaller. We simply do not know.

What This Actually Means

The Bolton and Kacperczyk paper is not just an academic curiosity. It has direct implications for investors, regulators, and anyone who cares about climate finance.

• ▸The market is not ignoring climate risk. Investors are demanding higher returns to hold carbon intensive stocks. This premium is visible in the data across 77 countries and 15 years. The narrative that markets are asleep at the wheel is wrong.

• ▸Regulation matters, but not in the way you think. Strict climate policies increase the carbon premium for emissions levels. Weak policies increase the premium for emissions growth. Both create incentives for firms to reduce their carbon footprint, but the mechanism is different. In strict regimes, the penalty is for being dirty today. In lax regimes, the penalty is for getting dirtier tomorrow.

• ▸Divestment is not a free lunch. If dirty stocks already trade at a discount, selling them transfers the discount to another buyer. The carbon stays in the atmosphere. The risk premium stays in the market. Divestment might be justified on ethical grounds, but it is not a financial arbitrage.

• ▸Active managers have a signal. The carbon premium is measurable and persistent. Managers who can identify firms with high emissions and credible transition plans can potentially earn the premium while hedging the downside. This requires granular data and a long time horizon.

• ▸The carbon premium is growing. As awareness of climate risk increases, the premium is likely to grow. This creates a feedback loop. Higher premiums mean lower stock prices for dirty firms, which raises their cost of capital, which makes new fossil fuel investments less attractive. The market is doing what markets do: pricing risk.

The surprise is not that climate risk is priced. The surprise is how much. Bolton and Kacperczyk have shown that the market's invisible hand is already reaching for the thermostat. The question is whether it will turn it down fast enough.