The CGD Podcast – "Who Pollutes Most? Surprises in a New US Database"

Guest: Kevin Ummel
Host: Lawrence MacDonald
Date: October 21, 2014

Overview

This episode of the Global Prosperity Wonkcast, hosted by Lawrence MacDonald for the Center for Global Development (CGD), features Kevin Ummel discussing his ground-breaking paper, “Who Pollutes? A Household Level Database of America’s Greenhouse Gas Footprint.” The discussion centers on the creation, findings, and implications of a newly assembled, high-resolution database detailing greenhouse gas emissions at the household level across the United States. The conversation delves into how emissions vary by income, geography, and political affiliation, and explores the policy and political consequences for carbon taxes in America.

Key Discussion Points & Insights

1. Production vs. Consumption-Based Emissions

• Most discussions around greenhouse gas (GHG) emissions focus on production-based emissions—what’s generated by factories and power plants.
• Ummel emphasizes the value of consumption-based accounting, i.e., tracing emissions back to the consumption patterns of individuals and households regardless of where goods are produced.
• Quote:

  "If you're interested in ethical questions around climate change or you're interested in questions of carbon taxes...you're much more interested in what we call consumption based emissions."
  (Kevin Ummel, 01:26)

2. What Counts as Personal Emissions?

• Americans typically think of their GHG emissions in terms of direct emissions (energy use in homes, gasoline, etc.), but this is only a fraction.
• Ummel’s research shows two-thirds of household emissions come from indirect sources: food, air travel, clothing, and other goods/services.
• Quote:

  "Those Direct emissions only account on average for about a third of the typical person's consumption based footprint. And the other 2/3 is coming from things like food and air travel, clothing, hotels..."
  (Kevin Ummel, 03:15)

3. "Embodied Carbon" – The Global Nature of Consumption

• MacDonald gives the example of a patio table from China, showing that U.S. consumer demand drives emissions abroad.
• Consumption-based accounting allows us to truly assign responsibility for emissions.
• International context: U.S. average per-person household emissions = 22 tons/year; China = 4-5 tons/year; India = <2 tons/year.
• Quote:

  "Looking at it from a consumption based standpoint I think gets us closer to information that is really meaningful, certainly in an ethical way."
  (Kevin Ummel, 04:48)

4. Headline Findings

• Pollution Inequality:
  • Top 10% of U.S. polluters = 25% of total GHG footprint.
  • Lowest 40% = only 20% of footprint.
  • Higher income people emit disproportionately more.
• Geographic Differences:
  • Highest GHG footprints found in suburban areas (e.g., Montgomery County and Fairfax County near D.C.).
  • Lower footprints in urban cores and rural areas.
• Political Geography:
  • Residents in Republican districts have slightly higher average GHG footprints than Democrats, but the difference is small.

5. Methodology

• Combined two major datasets:
  • Consumer Expenditure Survey (how households spend money).
  • American Community Survey (demographics, housing, location, energy use).
• Integrated environmental and lifecycle analysis data to estimate emissions from expenditures.
• The process required intensive computation but not supercomputing resources.
• Quote:

  "Find pieces of data that people haven't thought to put together before and put them together and see what new information you can generate."
  (Kevin Ummel, 08:58)

6. Suburban America: Highest Footprints

• Suburban counties (e.g., Montgomery, Fairfax) have disproportionately large household carbon footprints due to:
  • Big houses, long commutes, high car ownership, international travel.
  • Even within traditionally climate-concerned liberal enclaves, personal footprints are high.
• “Bobos” (Bourgeois Bohemians):
  • Ummel references David Brooks' term for affluent, educated liberals whose lifestyle is environmentally conscious in intention but high in carbon impact.
  • Within the Democratic party, there is a split: low-income, urban areas with low footprints vs. affluent, high-footprint areas.

7. Political Implications of Carbon Pricing

• Big Takeaway:

  • Household-level emissions in Republican and Democratic districts are very similar.
  • Therefore, a carbon tax would impact voters across party lines almost equally.

• Rational carbon tax policy could create winners in both red and blue districts, challenging the idea that only coal-heavy states would pay the cost.

• Historically, research and policy conversations have focused too much on macroeconomic impacts and too little on household and district-level effects.

• Quote:

  "The political rhetoric, the difference in political rhetoric is far greater than the difference in the environmental reality here."
  (Kevin Ummel, 17:09)

8. Potential for Progressive Climate Policy

• Ummel and MacDonald discuss the logic and political feasibility of a carbon tax & rebate (“tax and dividend”) plan:

  • High-income households (with large emissions) could absorb higher costs.
  • Rebates could be structured to ensure most low-income households come out ahead, making the policy highly progressive.
  • Such a policy could shift political incentives, making carbon taxes more palatable across party lines.

• Quote:

  "This is not a tax on success, this is a tax on polluters."
  (Kevin Ummel, 19:54)

• Notable Analogy:

  "I describe to me the politics of carbon taxes is like the politics of the Israeli Palestinian conflict. Rational people know where this is going to end up... Carbon taxes are going to end up with some sort of a carbon tax swap..."
  (Kevin Ummel, 19:44)

9. The Research Gap & Policy Design

• With granular data now available, future policy proposals can be crafted to show tangible gains for specific districts/constituencies—potentially breaking Congressional deadlock.
• Having household-level data means policymakers can visualize the direct impact of proposed climate fiscal reforms for their own voters.

Notable Quotes & Memorable Moments

• On the reality of who pollutes most:

  "So are you living in the suburbs where we see the highest footprints, or are you living in a rural area or in a high density urban area which tend to have lower footprints?"
  (Kevin Ummel, 11:21)

• On the “Bobo” paradox:

  "Bobos are this class of, of relatively wealthy, well educated, basically elites whose lifestyles attempt this very tenuous marriage of sort of social and environmental liberalism with relatively high consumption, high income lifestyles."
  (Kevin Ummel, 13:44)

• On the political future of carbon taxes:

  "It's going to end up with a two state solution, Israel and Palestine. Carbon taxes are going to end up with some sort of a carbon tax swap where we implement a carbon tax and we reduce labor capital taxes."
  (Kevin Ummel, 19:47)

• On policy targeting:

  "If we had the research in front of us to, like I said, go to members of Congress and show them, look, here's the policy package, here's the proposal, here's the consequences..."
  (Kevin Ummel, 20:49)

Key Timestamps

• 00:16: Introduction and context—Why household-level emissions matter.
• 01:26: Distinction between production and consumption-based emissions.
• 03:02–04:28: Explanation of direct vs. indirect (embodied) emissions.
• 05:17: Headline findings—pollution inequality, suburban hotspots, political geography.
• 06:42–08:03: Methodology—assembling and processing massive datasets.
• 10:34: Pollution inequality and the influence of income.
• 11:56–13:12: Suburban America as the epicenter of high emissions; specific D.C. counties discussed.
• 13:36–14:58: The “Bobo” paradox and political diversity within parties.
• 15:22–16:28: Similarity of emissions between Republican and Democratic districts.
• 17:06: Disconnect between political rhetoric and environmental reality.
• 18:28–20:49: Roadmap for a progressive carbon tax policy; progressive potential and political dynamics.
• 22:01: Looking ahead: research to inform real-world policy breakthroughs.

Conclusion

This episode provides a nuanced, data-driven look at greenhouse gas emissions in America, challenging stereotypes about who pollutes most and why. Ummel’s research highlights major inequities driven by income and geography, but also reveals surprising political commonalities that could open doors to bipartisan action on climate pricing. His call for using detailed, household-level data to design smarter, more politically robust carbon policies is both incisive and pragmatic—offering hope for breaking the logjam in U.S. climate politics.

The full report, “Who Pollutes?”, is available via CGD and is recommended for policymakers, activists, and anyone seeking to understand and act on the social side of America’s carbon footprint.