This MAY be very farfetched but hold my sparkling water: - Global temperatures started rising in ~1950 - US started installing ACs in ~1950 - 90% of US homes have AC - EU never did: only 19% of EU homes have AC (!) - Only 16% of the top EU companies were founded after 1950 - But 64% of top US companies were founded after 1950 Could it just all be down to having AC and being able to think clearly? Lee Kaun Yew, the founder of Singapore, said the #1 reason Singapore became rich was AC while its surrounding countries stayed relatively poor