As taken from the comments section. EMichael’s commentary on temperature and its impact.
“Air conditioning has changed demographics, too. It’s hard to imagine the rise of cities like Dubai or Singapore without it.
As residential units spread rapidly across America in the second half of the 20th century, the population in the “sun belt” – the warmer south of the country, from Florida to California – boomed from 28% of Americans to 40%.
As retirees in particular moved from north to south, they also changed the region’s political balance. The author Steven Johnson has plausibly argued that air conditioning elected Ronald Reagan.
Reagan came to power in 1980, a time when America used more than half the world’s air conditioning.
Emerging economies have since caught up quickly: China will soon become the global leader. The proportion of air-conditioned homes in Chinese cities jumped from under a tenth to more than two-thirds in just 10 years.
In countries like India, Brazil and Indonesia, the market for air conditioners is expanding at double-digit rates. And there’s plenty more room for growth: 11 of the world’s 30 largest cities are in the tropics.
The boom in air conditioning is good news for many reasons.
Studies show that it lowers mortality during heat waves. Heat makes prison inmates fractious – air conditioning pays for itself by reducing fights.
When the temperature exceeds 21C or 22C in exam halls, students start to score lower in math tests.
In offices, air conditioning makes us more productive: according to one early study, it made US government typists do 24% more work.
Economists have since confirmed that relationship between productivity and keeping cool.
William Nordhaus divided the world into cells, by lines of latitude and longitude, and plotted each one’s climate, output and population. The hotter the average temperature, he found, the less productive the people.
According to Geoffrey Heal and Jisung Park, a hotter-than-average year is bad for productivity in hot countries, but good in cold ones. They conclude that human productivity peaks at between 18C and 22C.”
And the math on the study of Nordhaus is way, way beyond my pay grade.
“ Geography and macroeconomics: New data and new findings”
Abstract: The linkage between economic activity and geography is obvious: Populations cluster mainly on coasts and rarely on ice sheets. Past studies of the relationships between economic activity and geography have been hampered by limited spatial data on economic activity. The present study introduces data on global economic activity, the G-Econ database, which measures economic activity for all large countries, measured at a 1° latitude by 1° longitude scale. The methodologies for the study are described. Three applications of the data are investigated.
First, the puzzling “climate-output reversal” is detected, whereby the relationship between temperature and output is negative when measured on a per capita basis and strongly positive on a per area basis.
Second, the database allows better resolution of the impact of geographic attributes on African poverty, finding geography is an important source of income differences relative to high-income regions.
Finally, we use the G-Econ data to provide estimates of the economic impact of greenhouse warming, with larger estimates of warming damages than past studies.