The 12 experts consider climate-related risks in seven world regions and a security risk perception survey of 56 other experts worldwide, 1 year, 10 years, and 20 years from 2020. Climate change not only acts as a threat multiplier but can have direct implications for military operations. Climate change-exacerbated water security is already a significant driver of instability and will pose a significant or higher risk to global security by 2030. All regions are facing more natural disasters, food insecurity, forced displacement, and conflict within and between nations. Climate mitigation and adaptation efforts are increasingly urgent to avert significant security consequences. Rising authoritarianism and nationalism are hampering needed cooperation. Security and military institutions must demonstrate leadership on climate security risks, and encourage governments to advance comprehensive emissions reductions and adaptation investments to avoid security disruptions.