SAA2-O-03 Introduction and Purposes: To prevent genocide, we have carried out preliminary explorations of the reciprocal relationships between Malthusian pressures, resulting from high population/low resource ratios and risks for genocide. Our purpose is to determine whether 1) Malthusian pressures and zero-sum rivalries for power over depleted, diminishing, or contaminated resources increase risks for genocide; 2) genocide increases risks for environmental degradation, including wanton environmental abuse, and vice versa; 3) the explanatory power of so-called “upstream” environmental indicators of carrying capacity depletion is sufficient to account for genocide without attention to the known political determinants of genocide; 4) unsustainable population/resource ratios increase risks for violence; and 5) intervention to prevent or stop genocide can be sustainable, without attention to preventing wanton environmental and ecologic abuse. Methods: Descriptive time lines for recent genocides and their precursors, population resource ratios for settings from recent genocides and settings without genocides, and case studies of effects of wanton ecologic abuse on vulnerable populations. Results: The histories of recent genocides (former Yugoslavia, Rwanda, and Darfur) confirm that 1) genocide cannot occur without the ideology and decisions of its authoritarian perpetrators, a lopsided intergroup power equation and indifference or indecision of outside bystanders; 2) simple population-land ratios do not appear to have explanatory power for vulnerability to genocide and mass atrocities; 3) Malthusian pressures, combined with choices to exacerbate zero-sum rivalries over water, arable land, or natural resources may have exacerbated the risks from known political and socioeconomic predictors in Rwanda and Darfur, but not in former Yugoslavia (Bosnia and Kosovo), which by themselves were not sufficient to result in genocide; 4) collapse of socioeconomic and governmental infrastructures following genocide produces massive sustained damage to carrying capacity and sustainability; 5) victims of mass atrocities, if they return to their environments and continue to be persecuted, have more severe problems than those of environmental refugees; and 6) wanton ecologic abuse can induce flight, death, injury, and multigenerational impacts, including genotoxic risks, without organized mass expulsions and violence. Conclusions: Simple descriptive comparisons of recent genocides do not appear to support the hypothesis that Malthusian pressures based on simple or more complex resource ratios account for genocide and mass atrocities. International early warning and effective response systems are needed to deter or prevent political decisions to carry out genocide. But these systems have to include long-term measures to resolve zero-sum conflicts over environmental resources and prevent toxic risks to vulnerable populations from wanton ecologic abuse.