LSE Public Lecture: Fault Lines – The New Political Economy of a Warming World

Host: Liam Bison McGrath (London School of Economics and Political Science)
Guest: Professor Helen Milner (Princeton University)
Date: November 10, 2025

Overview

This lecture, delivered by Professor Helen Milner, previews her forthcoming book (co-authored with Alex Gazmarian) and explores the emerging fault lines in the political economy of climate change. Far from a simple battle between climate “believers and deniers” or “green and brown” industries, Milner presents a compelling argument that climate change is reordering global and domestic politics along new geographic lines of vulnerability. The evening probes why climate mitigation efforts continue to stall, what motivates different actors to take climate action, how collective action (or lack thereof) is being reshaped, and what this means for global governance as climate impacts intensify.

Key Discussion Points & Insights

1. The Uneven Geography of Climate Vulnerability

• Central Thesis:
  Climate change does not affect all regions equally—some places stand to lose dramatically, while others may even see opportunities as temperatures rise.
• “Fault line” concept:
  The book’s main metaphor is a “fault line” (not unlike a seismic boundary) that marks a rough, not precise, global divide (around the 35th parallel) between:
  • The vulnerable South (largely below the “fault line”), more severely impacted and thus more motivated to act, and
  • The relatively shielded North (above the line), less exposed and slower or less motivated to implement costly climate policies.
• Quote:

  “One thing that is important to note... is that the geography of climate change is very uneven and unequal. That's the fault line that is the essence of what we're arguing in the book.”
  — Helen Milner [06:10]

2. Emissions, Peak Forecasts, and Policy Struggles

• Recent years have seen continued emissions growth, especially from China and other emerging economies.
• Attempts to globally peak emissions (“as thought in 2024/2025”) are slipping further out, with latest models now predicting 2030 or beyond.
• International agreements—like the Paris Agreement—have struggled to induce uniform action, as most countries miss their self-imposed targets.

3. Three Main Climate Strategies

• Mitigation: Reducing greenhouse gas emissions (transition from fossil fuels to renewables and possibly nuclear).
• Adaptation: Taking steps to minimize damage from unavoidable climate impacts (e.g., flood defenses).
• Geoengineering: Direct interventions in the climate system, such as removing atmospheric CO₂—a risky, poorly understood frontier.
• Quote:

  “…Adaptation is not going to stop climate change; it's just going to try and reduce the damage from climate change.”
  — Helen Milner [10:49]

4. Rethinking Prevailing Theories

• Past political economy theories of climate change focus on collective action and "free-riding," with a supposed North-South divide:
  • The North (rich, big emitters) should act, the South “free rides.”
• Milner argues:
  • Vulnerability, not wealth alone, now defines incentives.
  • The South (vulnerable) has more incentive to act, while the North is more reluctant—flipping conventional expectations.
• Reciprocity (mutual commitments), as assumed in Paris, is a weaker driving force than direct need and experience.

5. The “Climate Fault Line” Theory – Macro and Micro Components

Macro:

Geography—differential impacts create divergent interests across countries and regions.

Micro:

Learning—direct experience of climate shocks (wildfires, droughts, floods) is the key driver of belief and policy updating, more than ideology or advocacy alone.

• Quote:

  “Experience is what we call climate shocks... and in these vulnerable regions you're going to get even more of these. So we expect they'll be highly motivated to do things to mitigate more.”
  — Helen Milner [17:40]

6. Evidence Across Four Levels of Analysis

Milner and Gazmarian’s research systematically explores the effects of climate shocks and vulnerability across:

A. Individuals

• People in vulnerable areas (especially when experiencing shocks) are demonstrably more willing to support (even costly) mitigation policies.
• Democratic institutions amplify this effect by providing a channel for citizen pressure.
• Memorable moment:

  “People in areas that are very vulnerable are more likely to be willing to undertake costly mitigation policies and accept them.”
  — Helen Milner [30:28]

B. Firms

• Businesses in high-risk areas are more likely to lobby governments or seek to relocate (though actual movement is rare due to high costs); lobbying spikes in response to climate shocks.
• Multinational firms may use global value chains to diversify and “insure” against regional risk, sometimes “sacrificing” countries or regions with little recourse.
• Notable insight:

  “These climate shocks lead firms to update their beliefs and to be willing to exercise costly voice to get governments to change their behavior.”
  — Helen Milner [40:00]

C. Cities

• City governments in vulnerable regions are more proactive, innovating and borrowing from peers, despite lower resource capacity.
• Examples: Johannesburg (South, ambitious despite poverty) vs. Buffalo, NY (North, anticipates benefits from warming).
• Quote:

  “When we looked at what politicians were saying in Buffalo, it was: ‘Buffalo’s going to be warmer, more productive, a climate haven.’”
  — Helen Milner [43:54]

D. National/Global Politics

• The biggest “emitters” are now least motivated to cooperate.
• Southern states often adopt more mitigation laws (a shift from presumed free-riding), and many enact policies unilaterally, not reciprocally.

7. Backlash, North-South Divide, and the Limits of Collective Action

• Pushback in the North is predictable (“farmers, industries, right-wing parties”); higher perceived costs with limited direct risk.
• Many northern voters appear unmoved by southern suffering or pressure, nor are they swayed by moral or coercive tactics.
• Striking survey finding:

  “When you ask people in the north…what if the south tries coercion… it basically has no effect on their behavior. They’re not willing to say their government… should spend more on mitigation no matter what the south does.”
  — Helen Milner [47:30]

8. Possible Futures and Technological Hope

• Despite the gloomy outlook, Milner sees two powerful drivers for potential rapid transition:
  • Geopolitics: Even “unaffected” countries (China, EU) see value in energy security and global technological leadership.
  • Innovation and Cost Decline: Green tech costs dropping, reinforcing a “virtuous cycle.”
• Quote:

  “This I think is going to continue to drive things because … more usage leads to lower costs, and you get a virtuous cycle… So while our climate fault line story is difficult… there are other sides… to be a little bit more optimistic about the future.”
  — Helen Milner [52:05]

Selected Audience Q&A Highlights

1. Adaptation versus Mitigation ([54:25])

• Milner: Empirically harder to study adaptation, but expects similar North/South divides in motivation and resource willingness. The North drags its feet on both fronts, and even when pledging support, rarely follows through.

2. South-South Coalitions and Oil States ([60:42])

• Audience asks about hydrocarbon exporters like Guyana and Saudi Arabia, whose incentives diverge from non-oil South.
• Milner: The “global South” is not monolithic. Conflicts, resource dependence, and historic rivalries constrain cooperation—regional or limited-issue coalitions may be more viable than a grand South alliance.

3. US Internal Dynamics and Shifting Fault Lines ([63:03])

• Discussion of how the “fault line” runs within countries—e.g., in the US, southern (traditionally conservative) states are now most exposed, potentially shifting their behavior over time as climate shocks multiply.

4. Corporate “Zones of Sacrifice” ([65:01])

• Multinationals often “sacrifice” vulnerable areas (e.g., sweatshop countries) and diversify operations to minimize risk to themselves but not host communities. Supply chain flexibility blunts the incentive to lobby for climate action in some cases.

5. The Role of Political Economy versus Geography ([68:21])

• Ian Gough (LSE): Isn’t this just political economy? What about intra-North divergence (e.g., EU, US, China)?
• Milner: Geography, beliefs, and political structures all matter, but “climate shocks” are the main driver of policy and behavior updating—experience trumps ideology outside of elite-controlled narratives.

6. What Can Individuals Do? ([72:00])

• Q: How should individuals in the comfortable North act?
• Milner: Promote technological change, support the green economy and innovation, rather than attempt to “convince your neighbor”—personal experience is the catalyst for change.

7. Bill Gates’ Climate Letter ([74:11])

• Gates questioned the primacy of climate action over issues like poverty or disease.
• Milner: His investments still prioritize green tech; public statements may be politically strategic. “Existential” messaging may be misplaced in the North, but life-and-death reality in the South.

8. Arctic “Exception” ([77:06])

• Arctic region’s short-term increased habitability may mean some benefits, but long-term or unforeseen side-effects are likely; not all North is sheltered from impacts.

9. Capacity Gaps in the South ([80:13])

• Even when southern publics demand action, resource and institutional limits often blunt true mitigation; still, even controlling for income, Southern countries have adopted more laws per unit capacity—and in surveys, their publics display heightened willingness to support action.

10. Effective Climate Communication: Risks or Incentives? ([84:53])

• Milner: Messaging should be tailored—risk framing is less effective in the “comfortable North” unless shocks are personal, while in the South, risk is real and existential. Incentivizing innovation and co-benefits (e.g., cleaner air) may work better in less vulnerable places.

Notable Quotes with Timestamps

• On the core thesis:

  “It’s the countries below the fault line, which is most of the South, that had the greatest incentives to do things. It’s the North that’s going to be dragging its feet... We don’t think reciprocity is going to work.”
  — Helen Milner [19:32]

• On experience and belief updating:

  “Enough of these climate shocks…deviations from normal weather…are going to, in a sense, change their minds.”
  — Helen Milner [29:42]

• On public pressure in the South:

  “What we find… is that, even if the North doesn’t do anything, the South…the publics in the South think that actually they should try and mitigate.”
  — Helen Milner [47:05]

• On geoengineering risk:

  “The South’s best options may be unilateral geoengineering. And that’s very scary…if India starts messing with its atmosphere…is Pakistan going to see it as trying to attack it?”
  — Helen Milner [86:33]

Key Takeaways

• Climate politics is not just North vs. South but is increasingly defined by the complex, uneven geography of risk and opportunity—fault lines of vulnerability.
• Experience of direct climate shocks, more than ideology or Green-vs-Brown interests, is the primary driver of belief and action at all levels—individual, corporate, local, and national.
• International collective action is unlikely to be the norm. Most meaningful climate action will occur where it is most “needed” and will often be unilateral.
• Technological and economic factors—energy security and falling costs—could drive transformation even as the politics remain fraught.

Timestamps for Important Segments

• [04:00] – Introduction to climate politics and the “fault line” metaphor
• [17:40] – Macro and micro theory: geography and climate shocks
• [30:28] – Survey findings: individuals’ willingness to pay for mitigation
• [40:00] – Firm behavior and geographic vulnerability
• [43:54] – Buffalo vs. Johannesburg: case studies
• [47:05] – Global coalitions and “weapons of the weak” for the South
• [52:05] – The role of energy innovation and possible hope
• [54:25] – Q&A: adaptation, coalitions, US regional divides, firm strategies
• [68:21] – Integration of geography and political economy
• [72:00] – What individuals can do and the efficacy of climate communication
• [74:11] – Bill Gates’ open letter and the politics of billionaire climate messaging
• [80:13] – Southern capacity constraints
• [84:53] – Communication strategies: risk vs. incentive framing

Conclusion

Milner’s analysis cuts through simplistic narratives of climate politics, advocating for a paradigm that centers the real, lived experience of vulnerability. Climate shocks are reframing both global and local priorities, not always in ways that foster cooperation, yet changes—technologically enabled and necessity-driven—remain possible. As the world crosses climatic thresholds, this “fault line” is set to define political conflict and progress in the decades to come.