Is There a Link Between Weather and War? Re "Weather and Violence" (Sunday Review, Sept. Marshall Burke, Solomon Hsiang and Edward Miguel argue that climate change could increase violent group conflicts by 50 percent in the next 50 years. But I take strong issue with their starting point for this rise: "a planet already awash in conflict." As Ross Douthat notes in his column on an adjacent page ("War, What Is It Good For?"), the world is actually "more at peace than at any point in human history ... with fewer invasions, fewer war crimes, fewer massacres than in the past." Starting from today's low levels, a 50 percent rise over 50 years hardly registers. After all, world total battle fatalities jumped 65 percent just in 2011 to 2012 because of Syria, but remain less than one-fifth of the average level of the 1980s. Climate change, our top global challenge, is on track to kill many millions this century, but not from wars. The writer, a research scholar at the University of Massachusetts, Amherst, is the author of "Winning the War on War: The Decline of Armed Conflict Worldwide." Marshall Burke, Solomon Hsiang and Edward Miguel argue that their analysis of the literature establishes a strong link between weather and the level of violence in human society. As they know, however, this result has been met with some skepticism in specialist circles. On the other hand, there is universal agreement that poverty, inequality and weak civil institutions are at least as important as weather in explaining levels of violence. Policy makers must not lose sight of this in all the excitement about climate change. The writer is a senior scientist at the Woods Hole Oceanographic Institution.