Air conditioning is man’s location in the global landscape. It has allowed the development of parts of the world that were once too hot or too frigid for people to live in. In fact, various newer cities wouldn’t even be in existence without air-conditioning. Some of the world’s hottest cities came to life after the development of Heating plus Air Conditioning technology, and these cities continue to expand plus prosper, thanks to the revolution in heating plus cooling that allows people to bring in plus store food, medicine plus other supplies they cannot grow locally because of drastic local temperatures. But as more plus more “hot cities” come to life around the world, some scientists worry that the world itself will only get hotter. The rising need for energy will cause CO2 emissions to rise. CO2 is known to trap hot air in the atmosphere, thus overheating the planet. Thankfully, various of these so called “hot cities” are also sunny cities with plenty of wind. As such, they can take advantage of modern developments in energy science, such as solar plus wind, that will allow these places to power up well into the twenty-first century. Heating plus Air Conditioning technology is also becoming more helpful with the times, then some modern systems are completely powered by the sunlight plus can be adjusted to operate with the same or better efficiency as older systems while producing half the pollutions. Another plan being used to maintain the power plus efficiency of conventional air-conditioning while reducing pollution is smart controls. Twenty-first century air-conditioning technology is not simply managed through an ‘on/off’ switch or control unit. New units are synced to sophisticated online controls that can be adjusted in response to even minute changes in the environment or weather. These systems will allow hot cities to cut down on their energy use plus emissions while maintaining healthy temperatures in their homes, companies plus government edifices.