Slow Burn

1. The "Slow Burn" is Climate Change's True Threat

This book is about the deeper consequences of a hotter planet. It isn’t a climate change horror story. Nor is it a contrarian account of why we should all relax and direct our attention elsewhere.

Beyond Catastrophe. The prevailing narrative of climate change often focuses on looming cataclysms, invoking fear and despair. However, this book argues that the most insidious and damaging aspects of a warming world are the "slow burn"—the pervasive, often invisible costs that accumulate over time, affecting billions of people in subtle yet profound ways. This perspective challenges the doomsday framing, suggesting it may hinder proactive solutions.

Invisible Costs. Many significant impacts of climate change are not headline-grabbing disasters but rather incremental disruptions to daily life. These include imperceptibly elevated health risks, slight reductions in corporate profitability, the gradual erosion of livelihoods, and diminished learning capacity. For example, while a volcanic eruption like Vesuvius offers instant catastrophe, the slow, multi-century decline of the Roman Empire serves as a more apt metaphor for climate change's true nature.

Systemic Ripple Effects. The cumulative effect of these subtle setbacks may be far more harmful than commonly realized. They ripple through economic and social systems in unexpected ways, affecting everything from individual productivity and mental health to societal stability and economic opportunity. Recognizing these widespread, chronic impacts provides a compelling, immediate, and less morally charged reason to act swiftly on climate change.

2. Our Minds Underestimate Climate's Statistical Reality

Pulling all the pieces together to assess the costs and benefits of climate action—that is, determining whether 1.5°C of warming differs from 3°C or 4°C or more, and how those differences compare to the societal costs of achieving the necessary emissions cuts over time—all of this requires us to think statistically.

Cognitive Blind Spots. Human intuition, or "system one" thinking, is ill-suited for grasping the complex, statistical nature of climate change. We tend to focus on immediate, emotionally intense examples (availability heuristic) rather than long-term, probabilistic trends. This leads to a disconnect where most people believe climate change is happening but don't feel personally threatened, hindering informed decision-making.

Beyond Anecdotes. Weather fluctuations can obscure long-term climate trends, and dramatic events like hurricanes overshadow chronic issues. For instance, a cold snap might be opportunistically cited as evidence against global warming, despite overall warming trends. Overcoming these biases requires "system two" thinking—deliberative, statistical analysis—to discern true cause and effect from mere correlation or natural variability.

The Problem of Causality. Attributing specific outcomes to climate change is challenging due to numerous confounding factors. Rigorous scientific methods, particularly quasi-experimental designs and large datasets, are essential to isolate the causal impact of climate variables. This disciplined approach helps move beyond anecdotal evidence and cultural biases, providing a clearer, more dispassionate understanding of climate's real-world effects.

3. Hidden Human Capital Costs Dwarf Visible Disaster Damages

The $85 billion figure cited above does not account for any such learning disruptions.

Uncounted Losses. When natural disasters strike, official damage estimates primarily focus on physical capital—roads, buildings, infrastructure. However, the harm to "human capital"—the capacity for productive economic activity, including education and health—is often overlooked and unquantified. This omission significantly understates the true economic and social costs of climate events.

Learning Disruptions. Studies on events like Hurricane Sandy and Katrina reveal substantial, long-lasting educational setbacks.

• Hurricane Sandy: Shut down 1,750 NYC schools for a week, affecting over 1 million students, with ripple effects on learning.
• Hurricane Katrina: Students who evacuated New Orleans saw test scores drop by 7-20% of a standard deviation, equivalent to replacing average teachers with bottom 10% teachers for a year.
  These learning losses, if monetized, could be on par with, or even exceed, physical property damage.

Long-Term Impacts. Disruptions to education, especially for younger children, can have compounding negative effects on future earnings and opportunities. Research shows that natural disasters reduce student test scores and college enrollment rates, with these impacts scaling proportionally with physical destructiveness. These hidden costs exacerbate existing inequalities, as disadvantaged students are often hit hardest and have fewer resources to recover.

4. Heat Systematically Erodes Human Performance and Well-being

Taking an exam when the temperature was 90°F (32.2°C) outside reduced performance by around three to four points, which is small enough to be difficult to pick up with one or even a dozen students’ records.

Pervasive Performance Decline. Beyond catastrophic events, incrementally hotter temperatures subtly but significantly impair human performance across various domains. Laboratory experiments and real-world studies consistently show an inverted U-shaped relationship between temperature and task productivity.

• Cognitive Tasks: British naval officers made more Morse code errors in hotter rooms; NYC students performed 10% worse on exams at 90°F, affecting graduation rates.
• Physical Tasks: Professional tennis players double-fault more and run less in heat; manufacturing workers in India are 2-4% less productive per degree Celsius above optimal temperatures.

Aggression and Mental Health. Heat also negatively impacts human temperament and mental well-being.

• Aggression: Hotter temperatures correlate with increased road rage, aggressive penalties in sports, and violent crime (e.g., 9% increase in violent crime in LA on days above 85°F).
• Mental Health: Increased monthly mean temperatures are linked to higher emergency department visits for mental illness and a 0.3% rise in suicide rates in the US.

Economic Consequences. These widespread, subtle effects accumulate to significant economic costs. Earlier models underestimated these impacts, but new data suggests that heat-related productivity losses alone could reduce US GDP by 1-3% annually with 2°C warming, equivalent to wiping out the combined profits of the top 10 most profitable American companies.

5. Climate Change Deepens Global and Local Inequality

Countries that are 1°C hotter on average have per capita incomes that are approximately 8 percent lower on average.

Disproportionate Exposure. Climate change disproportionately affects poorer regions and populations.

• Global: Already hot, lower-latitude countries (often poorer) will experience much larger absolute increases in dangerously hot days (e.g., Bangkok sees a tenfold increase in >90°F days compared to New York City for the same average warming).
• Local: Within countries, poorer communities often reside in areas with higher heat exposure (e.g., low-income California zip codes experience nearly three times as many >90°F days as high-income ones), often due to less green space and more heat-absorbing infrastructure.

Vulnerability Amplified by Poverty. Lower-income individuals and nations are more vulnerable to climate impacts due to limited resources and adaptive capacity.

• Health: A 90°F day increases mortality in South and Southeast Asia by 1% (ten times the US effect), leading to potentially 126,000 extra deaths in India from a single such day.
• Workplace: Lower-educated workers are four times more likely to work in highly exposed occupations, and heat-related workplace injuries are five times higher for workers in the bottom income quintile.

Market-Driven Inequality. Market forces exacerbate these disparities. Housing markets price in "amenity premiums" for milder climates, pushing poorer residents into hotter, less desirable areas. This "residential sorting" creates localized climate inequality, often with racial overlays, as seen in hotter, less green neighborhoods in US cities.

6. Vulnerability is Shaped by Economic and Social Systems

The average district saw the impact of hot days on mortality fall by roughly 75 percent due to expanded bank penetration, from a 1.2 percent increase in mortality per day above 90°F (32.2°C) to a 0.3 percent increase.

Beyond Physical Tech. Climate vulnerability is not solely determined by physical hazards or individual physiology; it is deeply intertwined with a society's economic and social institutions. These institutions can act as either "shock absorbers" or "shock amplifiers," mediating how climate shocks translate into human suffering.

Institutional Buffers. Access to fundamental services and robust social structures significantly reduces vulnerability.

• Financial Access: In rural India, expanded access to banking services dramatically mitigated the impact of hot weather on mortality, suggesting financial stability helps households cope with climate-induced livelihood disruptions.
• Insurance & Markets: Weather insurance for Ghanaian farmers not only reduced risk but also "crowded in" other productive investments. Access to domestic and global markets provides implicit insurance against local yield failures.

Amplifying Factors. Conversely, certain institutional weaknesses can exacerbate climate impacts.

• Child Labor: In rural India, positive rainfall shocks led to children dropping out of school to help with bumper harvests, negatively impacting their long-term human capital.
• Informal Labor: The 60% of the global workforce in the informal sector often lacks basic protections like health or unemployment insurance, making them highly vulnerable to climate-induced income volatility.

Innovation Gaps. There's a critical need for "pro-poor" adaptation technologies and financial innovations, akin to malaria vaccine development, that the private market alone may not provide. This highlights a role for global philanthropy and coordinated efforts to fill market gaps in adaptation R&D.

7. Adaptation Requires Evidence-Based, Targeted Interventions

Will societies adapt to the successfully blunted but significant climate change that is in store in the twenty-first century? This chapter has highlighted the need for more nuanced and holistic approaches to adaptation, which consider not just technological fixes, but also the social and economic dimensions of climate change.

Beyond Silver Bullets. As significant warming is inevitable, the focus shifts from whether to adapt to how, how quickly, and at what cost. Grand public works like sea walls are appealing but expensive, and may divert attention from more mundane yet crucial adaptations. Effective adaptation demands a holistic approach, integrating technological, social, and economic solutions.

Addressing Market Failures. Government intervention in adaptation is justified where market failures hinder efficient private action.

• Information Asymmetries: Mandating climate risk disclosures (e.g., flood risk in real estate) or investing in accurate local climate forecasts can empower better decision-making.
• Credit Constraints: Policies addressing limited access to credit can enable households and firms to undertake costly but beneficial adaptation investments.
• Moral Hazard: Reforming subsidized insurance programs (e.g., flood or crop insurance) can incentivize private mitigation efforts.
• Public Goods/Externalities: Government support for urban tree cover or fire-resistant building codes can provide collective benefits that individuals wouldn't fully fund alone.

Evidence-Based Policy. New empirical methods allow for rigorous evaluation of adaptation strategies.

• Wildfire Codes: California's fire-resistant building codes significantly reduced home destruction and provided positive externalities to neighbors, proving cost-effective for new construction.
• Healthcare Access: Community health clinics in the US reduced heat-related mortality, demonstrating the protective role of public health infrastructure.
• Energy Subsidies: Targeted energy assistance programs for low-income households can prevent electricity disconnections during heat waves, mitigating health and financial stress.

Targeting the Vulnerable. Effective adaptation requires precise targeting, especially in data-poor developing countries. Innovations in remote sensing and big data (satellite imagery, mobile phone data) can help identify vulnerable communities and households, ensuring resources reach those most in need and maximizing the social return on adaptation investments.

8. Aggressive Mitigation is Economically Justified

The most recent update by the US Interagency Working Group places the social cost of carbon closer to $190 per ton.

Quantifying Externalities. Climate change represents a colossal market failure, where the costs of carbon pollution are externalized onto society. The "social cost of carbon" (SCC) quantifies these externalized damages in dollar terms, providing a critical tool for cost-benefit analysis of climate policies and guiding investment decisions.

Upward Revisions. Initial SCC estimates were low due to data limitations and simplifying assumptions. However, incorporating new, data-driven insights has led to significant upward revisions.

• Non-Market Damages: Earlier models largely ignored non-market impacts like mortality, morbidity, and labor productivity. New research, particularly on heat-related mortality, shows these are substantial, with temperature-related deaths alone accounting for nearly half of the total SCC.
• Empirical Damage Functions: More granular data and causal inference methods have refined damage functions, showing that many aspects of human well-being respond more sharply to higher temperatures than previously thought.
• Discounting: Evolving consensus on appropriate long-run discount rates, favoring lower rates, further increases the present value of future climate damages.

Economic Imperative. The latest SCC estimates (e.g., $190/ton) imply that current global emissions cause trillions of dollars in annual damages. This makes aggressive emissions cuts economically rational, as the benefits (avoided damages) far outweigh the costs of mitigation. For example, achieving 75% global emissions cuts (costing ~$3.1 trillion/year) is justified by the ~$6.65 trillion in annual avoided damages.

9. Incremental Action Offers Active Hope, Not Fatalism

Every increment of warming prevented by the world today can mean billions if not trillions of dollars in damage avoided tomorrow.

Progress, Not Perfection. While the "climate catastrophe" narrative can induce fatalism, significant progress has been made in reducing worst-case warming scenarios. Global emissions trajectories have improved, and clean energy technologies have seen dramatic cost reductions. This partial success underscores that every effort to reduce emissions, no matter how small, yields tangible benefits.

Marathon, Not Sprint. Decarbonization is a multi-decade endeavor, requiring sustained effort and investment. It's not a binary "solve or fail" situation; rather, it's a continuous spectrum where every fraction of a degree of warming avoided translates into billions in avoided damages and reduced suffering. This incremental perspective fosters "active hope" rather than despair.

Beyond the Red Line. The focus on symbolic temperature thresholds (e.g., 1.5°C) can be misleading. Even if these are surpassed, continued mitigation efforts remain crucial. A nuanced understanding of non-catastrophic damages provides a robust economic and moral case for ongoing climate action, emphasizing that it's "never too late" to make a difference and improve outcomes for future generations and the natural world.

Last updated: December 10, 2025