How Climate Shocks Produce Armed Rebellion: The 1970 Bhola Cyclone and the Birth of Bangladesh -- by Sultan Mehmood, Ahmed Mushfiq Mobarak

Why do climate shocks produce conflict (Hsiang et al., 2013)? We study the 1970 Bhola cyclone in East Pakistan, one of the deadliest natural disasters in recorded history, which killed an estimated 350,000 people. Using satellite imagery, archival records, electoral returns, and insurgent biographies, we show that cyclone exposure amplified pre-existing separatist sentiment at the ballot box and increased citizens’ subsequent participation in guerrilla warfare against the state. Our estimates imply that exposure to the cyclone’s devastation induced an additional 48,613 insurgents to join the guerrilla war effort. Effects are larger in areas with pre-existing political and economic grievances and weaker relief provision. Our analysis reveals the step-by-step mechanisms through which environmental shocks can produce conflict: they shift voting behavior, expose state indifference, and convert grievance into armed mobilization.