For many areas, Life would be impossible without air conditioning.

 GEOGRAPHICAL TRENDS CHANGED DUE TO AIR CONDITIONING

MAKING LIFE POSSIBLE IN HOSTILE CLIMATES

Air conditioning was invented in 1902. It was huge, expensive and just an idea, but not available for consumers. This began to change in the early 1930's as technology began to make units smaller and soon affordable for the mass market. In 1947 43,000 units were sold, but it was in the 1970's that air conditioning began to become part of everyday life for everyone.

We see high temperatures in places like Phoenix and Houston that would be deadly without air conditioning. In fact, much of the south was not a comfortable place to live in the past, particularly in the summer. The native Americans often migrated south in the winter and north in the summer. Most did not live in place like Phoenix, if in Arizona, it was in the higher elevations. 

The history of these places is revealing, Phoenix had a population of 221,000 in 1950, some years after air conditioning became available, now 4.7 million. Houston 1950, 709,000, today 6.7 million. Tampa 1950, 300,000 today 3 million. Las Vegas 1950, 35,000, today 2.8 million. Miami 1950, 622,000 today 6.2 million. Then compare it with Chicago 1950, 5 million, today 8.9 million. I suspect the population in these southern areas was much lower in the 1930's.

Florida was a place were the wealthy spent the winter in the 1940's and 50s, but not too many retired there permanently. It was just too hot.  I remember in the 1950's when they sold lots in Florida through the mail, very low cost and often filled in swamp land. Without air conditioning the world would be a different place.

Today even large buildings in the north are now dependent on air conditioning as they often do not have windows that open. They would be deadly without electric and air conditioning.

Like many things today, most people just take it for granted that these inventions have always been available and will always be in the future. I sometimes suspect that nature will always revert back to its power sooner or later.