The question whether it can be shown statistically, that indicators of climate change are linked to the likelihood of civil wars is hotly debated. Michael Brzoska is part of a large group of experts who skeptically commented on a study strongly supporting this claim.
Halvard Buhaug, Jonas Nordkvelle, Thomas Bernauer, Tobias Böhmelt, Michael Brzoska et al, One effect to rule them all? A comment on climate and conflict, Climatic Change, December 2014, Volume 127, Issue 3-4, pp. 391-397.