Climate Adaptation

Paper Session

Sunday, Jan. 8, 2017 1:00 PM – 3:00 PM

Hyatt Regency Chicago, Acapulco
Hosted By: American Economic Association
  • Chair: Antonio Bento, University of Southern California

Adaptation and the Mortality Effects of Temperature Across United States Climate Regions

Garth Heutel
,
Georgia State University
Nolan Miller
,
University of Illinois-Urbana-Champaign
David Molitor
,
University of Illinois-Urbana-Champaign

Abstract

We study the relationship between temperature and elderly mortality across US climate regions and its implications for adaptation to climate change. Using daily weather matched to all Medicare beneficiaries from 1992 – 2011, we show that the mortality effect of hot days is much larger in the coolest third of ZIP codes than in the warmest third, and the opposite is true for cold days. While prior predictions based on homogeneous temperature effects imply warming may be beneficial in cool regions, our results suggest that warming is much more harmful in cool regions than in warm regions. As evidence of regional adaptation to local climate, replacing the temperature distribution of any climate region with that of another region — either hotter or colder — results in higher mortality. Comparing effects across states, as the frequency of days within a given temperature range increases, excess temperature-related mortality declines on those days. As one adaptive mechanism, we find that ZIP codes with greater air conditioning penetration have substantially lower mortality due to heat, but little difference in cold-driven mortality. Using climate projection models to predict the temperature distribution at the end of the century, we find that failure to incorporate heterogeneity in the temperature-mortality relationship results in predicted regional mortality effects that are wrong in sign, and overall predicted mortality effects that are roughly 50 percent too small in magnitude.

Quantifying The Short and Long Run Impacts Of Climate Change On Residential Energy Consumption Using Big Data

Maximilian Auffhammer
,
University of California-Berkeley

Abstract

The widespread rollout of air conditioning has resulted in massive positive impacts on human health in both developing and developed countries over the past century. A warming world will further increase demand for cooling in climates both through increased operation of existing air conditioners and the adoption of new ones. This paper provides an empirical approach to separately quantifying the intensive and extensive margin response without having to make explicit assumptions about the current day or future penetration of air conditioners. Exploiting a panel dataset containing close to two billion electricity and natural gas bills for California, we estimate the temperature response of residential consumption at the zip code level. Using the most recent set of IPCC climate models, we simulate future consumption by letting households vary consumption along their current response function as well as letting the response function change using an econometrically estimated second stage. We show that overall increase in residential electricity consumption is modest, yet failing to account for extensive margin adjustment leads to drastic underestimate of future impacts.

No Adaptation to Climate During One Millennium of Irish History

Solomon Hsiang
,
University of California-Berkeley
Francis Ludlow
,
Trinity College Dublin

Abstract

It is almost universally assumed that given sufficient time to learn through experience, human populations adapt to their local environment. This intuition is grounded in the notion that many small and seemingly costless innovations and changes in behavior may aggregate into social and economic systems that are robust to regularly experienced events. The logical conclusion of this assumption is that over time, populations are affected less and less by environmental hazards. Here we show that Irish populations exposed to a relatively unchanging environment for an entire millennium failed to adapt to regularly occurring climatic events. Examining the Chronicles of Ireland, annual monastic records from 600-1600 AD, we find that cold or wind extremes systematically increased the probability of major animal mortality events, agricultural losses, famines, and major human mortality events by roughly 20-40%. Surprisingly, this relationship does not systematically diminish with time and persists through the rise and fall of different political systems, indicating that even extensive experience with climatic conditions are not sufficient to induce adaptation. This result challenges widespread assumptions used in social and economic projections of how effectively future populations will adapt to climatic changes. Although our findings draw on historical data, we note that average incomes in Ireland during this period are similar to those in many African countries today.
Discussant(s)
Matthew Neidell
,
Columbia University, IZA, and NBER
Joseph Shapiro
,
Yale University
Matthew Kotchen
,
Yale University
JEL Classifications
  • I0 - General
  • Q5 - Environmental Economics