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The Technopolitana Collection of BIG numbers:

The air conditioner was invented, around 1900. We are approaching a time when there will be more air conditioners in the world than there were people in 1900.

There were 1.65 billion people in the world in 1900 and now there are now around 1.65 billion air conditioners.

Air conditioners create so much waste heat that it is estimated that, if four houses in a development have them, the rise in exterior heat will be enough to induce the fifth to have one too. (source -- New York Times -- citing a report by the International Energy Agency, May 15, 2017)
The International Energy Agency Report goes on to suggest that this number will increase by 3x to 5.5 billion air conditioners by 2050. That will use as much electricity as is being used by China for domestic purposes today.

Skip Forward to: Land Area of the Globe -- Proposal -- World Population Figures -- Flying -- people per square mile (notes only)


WORLD POPULATION was already 2.4 million people in 12,000 BC. It is estimated it rose to around 300 million by the year 0, the time of Christ.

After that world population increased about 3 x to 1800, just after the French and American revolutions when it edged towards a billion. This was just before the Industrial Revolution proper started, or accelerated.

As opposed to increasing by 3 x in 18 centuries, world population has increased around 4 x in the twentieth century alone -- from approximately 1.65 to 7+ billion by the year 2000.

In a different equation world population has increased around 3 x since the beginning of widespread use of antibiotics. The two are not exactly linked, nor are they exactly unlinked.

There are strong signs of rate of increase in world population rounding off or slowing or even declining, or being forecast to decline.

That said, CAR OWNERSHIP suggests that the ownership of energy consuming THINGS will continue to increase way above the increase in population.

Car Ownership in the USA was 1 per 10,000 people in 1900, 10 per 10,000 in 1905, 2100 by 1930 and 8000 per 10,000 by the year 2000. Interestingly, according to the Transport Energy Data Book written by Susan E Williams and Robert G Bundy, US car ownership reached its peak in 2005 although it is rising again since the great recession.

According to China Automotive News (Gasgoo) of  18 Oct 2018, China had 235 million cars on the road. According to Jonathan Watts writing in the Guardian (20-Oct-11), China increased car production 20 x between 2000 and 2010. If China's ownership of cars follows the American trend, the total number of cars in China will about quadruple -- a billion cars.

While the ENERGY EFFICIENCY of CARS has increased significantly since the gas-guzzlers of the 1950s, there are signs that affluence in many parts of the world is reversing the trend and the current move is to less efficient cars. There is also the issue of the road space required by cars, let alone the parking space. Spaced Out: Perspectives on Parking Policy published by the Royal Automobile Club Foundation in 2012 (and discussed in the Guardian 18-July-12) suggests that the number of British houses with front gardens now paved for parking has increased to 7 million homes.

If we take a rough figure -- an underestimate -- of a car taking up 3 x 2 metres to park, 7 million homes means a loss of about 10,300 acres of green space to cars. If an actual football field is 1.32 acres, this is the equivalent of nearly 8000 football pitches lost to green space by car parking.


Map -- the South of England in Roman Times, c 100AD -- hand colored engraving published by Laurie & Whittle, London, 1794.
Roman Britain population around 3 million, 1801 when the map was published, first census, around 10 million, current 2019 population 66 million + or -.
With a land area of about 94,000 square miles, the UK has 700 people per square mile (270 per sq km), up 7x  from 94 per sq mi or 36 per sq km in Roman times.

On the United Nations Population estimate chart, the UK comes 53rd of 241 countries in terms of population density. Smaller islands and concentrated countries like Hong Kong head the list.
Some other examples of high density:
Bangladesh 165 million people/ 2900 people per sq km (10x UK).
South Korea 48 million people/ 1261 per sq km (4.5x UK)
Netherlands 17 million people/ 1080 per sq km.
India, Belgium, the Philippines, Vietnam all exceed the UK population density.
The USA is 179th of the 241 countries with 241 per sq km.
Australia and Canada are around 9 people per sq km.
Least densely populated of countries with over 2 million people are Mongolia (approx 7 people per sq km) and Namibia (approx 4 per sq km)
Bottom of the list is Greenland which has a population of 57,000 giving them 10 km each, much of it ice -- for the moment.


Land Area of the Globe

Total Land Area of the Globe:             148,940,000 square kilometers, think of 149 million.

Total area of the sea:                      361,132,000 square kilometers, so more than twice as much as land.

Amount of land area covered by snow & ice: about 15,000,000 square km.

This leaves about 134,000,000 square km. In hectares that is x 100 so 13,400,000,000 hectares of theoretically habitable land – 13 billion.

A sq km is difficult to visualize. A hectare is approx the size of a football field. The world is 13 billion football fields.  So in the year 0 we would have had about 4.5 hectares each, four & a half football pitches. Each.

Now we have  land area for 7.4 billion of us. Except for stacking up in high rises and places like Dubai which build islands, land does not grow. And deserts have tended to get bigger.

So now we have about .5 hectares each, half a football pitch.

That is about 100 meters long x 50 wide.

One problem is you don’t want to get assigned the half football pitch in the tundra. Nor in the Sahara desert.

In order to pass through the bottleneck (of population growth), a global land ethic is urgently needed – E.O. Wilson, The Future of Life prologue p xxiii.

Data from the International Livestock Research Institute in Kenya This states 1.4 billion cattle and 19.6 billion chickens worldwide.

That is, roughly, one beef or milk cattle head per 5 people and 2.5 chickens per person.

"You may think you live on a planet, but really you live on a gigantic farm…" cited from TIME magazine (16-Dec-2013).

Various indications suggest that about 40% of the non-ice global land area is used for farming. The Time Magazine article is well worth sourcing as a primer for information in this area.


FLYING: This is contentious. Many people are aware that flying is polluting. Almost no one is prepared to admit that their next flight is the one than can be avoided.

If in doubt about this, search the web for ways a passenger can cross the Atlantic from Europe to the Americas without flying. There are possibilities. Apart from ‘top’ cruise ships which go irregularly there is not much else.

Allowing half an hour check in for a long distance train – it can often be done in less – and two hours for a flight, it is faster to fly distances above 500 miles.

London to Glasgow (about 350 miles) is 1 ½ hrs[i] by air plus 2 hrs check in + ½ hr get out = 4 hrs.

London to Glasgow train is 4 ¾ hrs + ½ hr check in + ¼ hr get out = 5 ½ hrs.

TGV trains would do this faster. At 200 mph the London to Glasgow train with a stop or two would take 2 hrs + ½ hr check in + ¼ hr depart = 2 ¾ hrs – beats the plane.

London to Rome is 1,150 miles.

London to Rome by air is 2 ¼ hours. Add 2 hrs + ½ hour = 4 ¾

London to Rome by train – average time 16 hrs + Fastest 14 hrs +. With longer international check in this = about 18 hrs.

London to New York by air is about 7 ½ hrs (faster west-east than east-west). Add 3 hrs check in and arrival customs = 10 ½

London to New York at 200 mph by TGV train would be 17 hrs, not bad and not an option. London to New York by sea 3-5 days. The SS United States did the distance in 3 days 12 hrs, holding the record, this in the 1950s, the last decade before flying became the norm for most people.

FLYING IS FAST – now for the big number.

7% is the big number. 7% is the approx year on year increase in passenger flights taken world wide.

In 2004, less than 2 billion person-flights were taken. For 2018 the number is 3,970,000,000[ii] person-flights taken.

In 1970 there were already 310,000,000 flights taken.

The website FlightRadar24 reported 202,157 flights in the air during the 24 hours of June 29, 2018. That was a record.

There are many estimates of how many people are in the air at any one time. Spike Aerospace, developer of a new generation supersonic airplane – perhaps an unusual source, suggest about 500,000 people at any one time and 6 million people per day.

This would calculate into much less than the 3.7 billion person-flights (see above).[iii]

The actual number of people flying is probably more like ten million per day.


These are two big numbers which are both 0.   0 is the amount of tax worldwide on airline fuel – more accurately close to 0 and 0 in many places.

0 is, until some tame attempt to regulate in 2016, the extent to which flying was a factor in climate change talks.

In 2016 the International Civil Aviation Organization (ICAO – a United Nations body)  developed CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation)[iv].

The big number here really is the M (for Murky) number. Whoever wrote the Wikipedia article on the subject of airplane emissions, which is generally excellent, became baffled in trying to relate the CORSIA agreement into any kind of number – a satirical view of this would say that CORSIA is a nice way of saying nothing very much has to be done for quite some time and that when it does it won’t really change anything.

The author of this BIG NUMBERS entry has had the same difficulty. The CORSIA agreement can be found online – there is not much that is comprehensible about it except that weak emotion, vague hope.

In fact the basis of the agreement, or its ideal, is to try to design a carbon offset system for the amount of carbon put into the atmosphere by planes above the 2020 level.

It is also possible to argue as the website ‘how stuff works’ does that a Boeing 747 full of 500 people can achieve 100 miles per gallon per person which is a lot better than a car that does, say, 40 miles per gallon.

The argument is based on the fact that a Boeing 747 burns 5 gallons of fuel per mile. Divide this by 500 people on the plane and you get the 100 miles per gallon with the plane flying at 550 miles per hour.

Boeing 747s are not the most economical of planes. Recently a good deal is heard about the new generation achieving fuel efficiencies. There is also data to suggest tht these efficiencies are related to the inefficiency of early jet engines. Exact data is hard to pin down. It would appear that today’s planes are flying at about the same efficiency and the propeller airplanes like the Constellation that achieved long distances in the late 1950s.

Here is another low number. 2% was considered the civil aircraft contribution to carbon emissions in 1999.[v] This was cited in an Intergovernmental Panel on Climate Change report, Aviation & the Global Atmosphere. Calculations from The Environmental Change Institute at Oxford University have suggested doubling this figure to 4%.

According to Wikipedia In Europe, the average airline fuel consumption per passenger in 2017 was 69 miles per gallon (in US gallons, so slightly higher in UK gallons). This was down 24% less from 2005.

Offset the increase in passenger miles between 2005 and 2017 and one ends up with an increase of 16% in emissions. But as the traffic grew by 60% to 1,643 billion passenger kilometres, CO emissions were up by 16% to 163 million tonnes for 99.8 g/km CO per passenger.

 Skip Back to: Land Area of the Globe -- Proposal -- World Population Figures -- Flying -- Air Conditioners

READER -- PLEASE NOTE: This is a work in progress, incomplete and not properly footnoted or formatted.

[i] Checked from flights, BA & Easyjet








The Technopolitana Collection of Big Numbers is a work in progress.




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