Causality Chain · Audit Detail
US Dust Bowl 1930-1940
dust_bowl_climate_migration · order-2 · AP HuG subtopic 5.10 · status rated
A
Composite 12.00 / confidence high
Grade A: 3 sources, source_quality_avg=4.00, corroboration=2, claim_strength=3, geo_specific=1, counter_evidence_handled=yes.
The historical event
US Dust Bowl 1930-1940 · 1930 · US Great Plains (OK, KS, TX panhandle, CO, NM)
Industrial wheat farming + drought + topsoil erosion → 2.5M people displaced from Plains 1930-1940. Steinbeck's Grapes of Wrath population.
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Causal trigger + effect
Trigger
Card(s):
subsistence_to_commercial_agConditions:
—Threshold:
—Effect
Type:
auto_play_cardPayload:
{'card_id': 'climate_migration'}Target: self
Delay turns: 2
Methodology subscores
| Dimension | Score |
|---|---|
| Source quality (avg) | 4.0 |
| Corroboration (independent sources) | 2 |
| Causal-claim strength | 3 |
| Counter-evidence handling | 1 |
| Geographic specificity | 1 |
| Temporal scope | 1 |
Primary sources (3)
Worster, D., 'Dust Bowl: The Southern Plains in the 1930s', Oxford UP 1979
Type:
peer_reviewed · Year: 1979 · Geography: US Southern PlainsDefinitive environmental history; Bancroft Prize winner. Linked commercial farming to ecological collapse.
Cunfer, G., 'On the Great Plains: Agriculture and Environment', Texas A&M 2005
Type:
peer_reviewed · Year: 2005 · Geography: US Great PlainsQuantitative geographic analysis; partially revised Worster's framing — drought as primary, plowing secondary.
Egan, T., 'The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl', Houghton Mifflin 2006
Type:
journalistic · Year: 2006 · Geography: US PlainsNational Book Award; oral history + research synthesis.
Counter-evidence (1)
Cunfer (2005) argued drought was primary driver, with industrial farming amplifying but not causing the Dust Bowl
Source: Cunfer 2005 · Weight:
moderateAudit metadata
Audit ID:
d53393142ed14d1cac5b50192f5aba00Audit date: 2026-05-14T05:54:39.790896+00:00
Protocol version:
v1.0Rater: claude_sprint2_auto
Corroborating independent count: 2