Humans are a geological force. For instance, at any given moment there is 1.5 billion tonnes of material being moved around on wheels on the surface of the Earth, thanks entirely to our efforts.
number of motor vehicles, including trucks and commercial vehicles 900,000,000 (http://carsandpeople.sdsu.edu/)
number of cars in the world 750,000,000 average weight 1.3 tonnes number moving at any one time cars parked 90% of time (http://en.wikipedia.org/wiki/Automobile#Driverless_cars), so assume they’re moving 10% of the time.
number of trucks and other vehicles 150,000,000 average weight of tractor/trailer 13 tonnes number moving at any one time – assume 8 hours/day per truck typical so 33% of the time.
cars moving at one time = 10%x750,000,000 = 75,000,000 weight = 75,000,000×1.3 tonnes = 97,500,000 tonnes.
trucks moving at one time = 33%x150,000,000 = 49,500,000 weight = 49,500,000×13 tonnes = 643,5000,000 tonnes.
so at any one time there are approximately 693,000,000 tonnes of vehicle moving on wheels, say 700 million tonnes.
This does not include passengers and payloads.
trucks carry between 3 and 36 tonnes, cars with 1.5 occupants are carrying, say 150kg = 0.15 tonnes.
for the sake of argument then, let’s say commercial vehicle payloads approximate 15 tonnes each, so travelling at any one time 49,500,000×15 tonnes = 742,500,000 tonnes.
cars 75,000,000×0.15 = 11,250,000 tonnes.
so cars plus passenger = 97,500,000+11,250,000 = 108,750,000 tonnes in motion. commercial vehicles plus payloads = 693,000,000+742,500,000 = 1,435,500,000 tonnes in motion.
This assumes that ‘motor transport’ refers only to wheeled road traffic and does not include, rail, air or sea travel.
total mass in motion due to motor transport at any given time = 1,544,250,000 tonnes, say ‘over 1.5 billion tonnes’. Think 1.5 cubic kilometres of water or 600,000 olympic swimming pools…
If you take the average weight of a human as 50kg (all ages) (http://www.answerbag.com/q_view/283254) and the number of humans on the planet as 7 billion, then the total weight of humans is 50×7 billion = 350 billion kg = 350 million tonnes.
The total mass of material moving on wheels at any time is about 4.4 times the weight of all humans on the planet! We’re geology! We’re a force of nature!
PFD 18 April 2010
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