**2. Re-focusing for the future**

The current book reflects the current "out-of-pandemic" transition while ensuring that our focus on the overall "health security" remains laser sharp, primarily because numerous international health security threats remain. The biggest and most pronounced contemporary challenges are now clearly emerging, and the now undisputed climate change dominates the priority list [3]. As these words are being written, forest fires rage across numerous geographic areas of the world, while a combination of unpredictable flooding and droughts (due in large part to climate-dependent redistribution of water resources) threaten to make entire regions of the planet uninhabitable. Along with climate change, we are very likely to see an increase in natural disasters and various other health risks. Among these emerging health risks are malnutrition/food insecurity, the appearance of invasive species, and acceleration in discovery of novel pathogens [4]. Accordingly, these "continuation and readiness" themes warrant more attention and in-depth discussion. Regarding the specifics of climate change, what is also of substantial concern are not just the primary issues (as mentioned), but also some of the unknown and/or intended consequences that will only be fully appreciated as we collectively experience this global megatrend. For example, recent heat waves in England have impacted airport runway and train track usability—and hence the mobility of a work force that resulted in reports of healthcare workers being unable to travel to work in remote areas of the country. Similar concerns are occurring across the world and involve a mixed array of factors, from extreme heat waves, to rapid saltwater intrusion across coastal freshwater reservoirs, to tidal flooding and to extreme wind events such as cyclones, hurricanes, and tornadoes [5, 6].
