In large parts of the developing world agriculture remains a broad economic sector securing livelihoods for large parts of the population. In the discourse on security implications of climate change, effects on agricultural production and food insecurity are frequently claimed to be a plausible intermediate causal connection. Earlier research has linked economic shocks to conflict outbreak but loss of income from agriculture may also affect dynamics of fighting in ongoing conflicts. We identify three complementary processes through which loss of food production may escalate enduring conflicts: lowered opportunity costs of rebelling, increased opportunities for recruitment, and accentuated and more widespread social grievances. Using India as a test case, we investigate how year-on-year fluctuations in food production affect the severity of ongoing armed conflicts. The statistical analysis shows that harvest loss is robustly associated with increased levels of political violence. To the extent that future climate change will negatively affect local food production and economic activity, it appears that it also has the potential to fuel further fighting in areas that already are scenes of chronic conflict.