Evidence map›Paper›PMID 19717432›Full record

ArticleProceedings of the National Academy of Sciences of the United States of America2009

Nonlinear temperature effects indicate severe damages to U.S. crop yields under climate change.

Wolfram Schlenker, Michael J Roberts

Abstract read
In one paragraph

Article in Proceedings of the National Academy of Sciences of the United States of America, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 326 papers.

0numbers the graph read from it
0cells of the map it votes in
326citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

326 citing papers in PubMed.

  1. Review
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  7. Ambient heat and early childhood development: a cross-national analysis.Journal of child psychology and psychiatry, and allied disciplines · 2026
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  11. Weather forecasts become more important for reducing mortality as the climate warms.Proceedings of the National Academy of Sciences of the United States of America · 2026
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  12. Review
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266 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

5 · Who and what money

Authors and funding

2 authors.

Wolfram SchlenkerDepartment of Economics and School of International and Public Affairs, Columbia University, New York, NY 10027, USA. wolfram.schlenker@columbia.edu
Michael J Roberts

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The United States produces 41% of the world's corn and 38% of the world's soybeans. These crops comprise two of the four largest sources of caloric energy produced and are thus critical for world food supply. We pair a panel of county-level yields for these two crops, plus cotton (a warmer-weather crop), with a new fine-scale weather dataset that incorporates the whole distribution of temperatures within each day and across all days in the growing season. We find that yields increase with temperature up to 29 degrees C for corn, 30 degrees C for soybeans, and 32 degrees C for cotton but that temperatures above these thresholds are very harmful. The slope of the decline above the optimum is significantly steeper than the incline below it. The same nonlinear and asymmetric relationship is found when we isolate either time-series or cross-sectional variations in temperatures and yields. This suggests limited historical adaptation of seed varieties or management practices to warmer temperatures because the cross-section includes farmers' adaptations to warmer climates and the time-series does not. Holding current growing regions fixed, area-weighted average yields are predicted to decrease by 30-46% before the end of the century under the slowest (B1) warming scenario and decrease by 63-82% under the most rapid warming scenario (A1FI) under the Hadley III model.

Indexed as

Greenhouse EffectModels, BiologicalCrops, AgriculturalDatabases, FactualGlycine maxGossypiumNonlinear DynamicsTemperatureUnited StatesWeatherZea mays

Identifiers

PMID19717432
PMCPMC2747166

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.