CrazyNeutrino said:
A planet’s worth of human-made things has been weighed
A new report has calculated the total mass of all the technology humans have produced, everything from buildings to cars and computers, and found it is an astounding 30 trillion tons. That is more than the total amount of living matter on Earth. It shows the sheer magnitude of the human impact on our planet, which is still growing.
By contrast, the total amount of living matter, including people, plants, animals, insects and bacteria is estimated to be around 4 trillion tons of carbon. Our technology and everything that comes with it is literally larger than life.
More…
Full article at http://anr.sagepub.com/content/early/2016/11/25/2053019616677743.full.pdf+html
Scale and diversity of the physical technosphere: A geological perspective
Table 1. Approximate mass of the major components of the physical technosphere, arranged in order of
descending mass (where 1 Tt = 10^12 metric tonnes).
Component Area (106 km2) Thickness (cm) Density (g/cm3) Mass (Tt) Percent (%)
Urban areas 3.70 200 1.50 11.10 36.9
Rural housing 4.20 100 1.50 6.30 20.9
Pasture 33.50 10 1.50 5.03 16.7
Cropland 16.70 15 1.50 3.76 12.5
Trawled sea floor 15.00 10 1.50 2.25 7.5
Land use and eroded soil 5.30 10 1.50 0.80 2.7
Rural roads 0.50 50 1.50 0.38 1.3
Plantation forest 2.70 10 1.00 0.27 0.9
Reservoirs 0.20 100 1.00 0.20 0.7
Railways 0.03 50 1.50 0.02 0.1
Totals (where applicable) 81.83 30.11
Notes: Spatial extent is based partially on Hooke et al. (2012), and information on approximate thickness and density are
from Ford et al. (2014), Edgeworth et al. (2015) and Gattuso et al. (2009).
OK, I thought I wasn’t right to trust it. let’s look at the first row.
Urban areas: Area 3.7 million square kilometres, thickness 2 metres, density 1.5 grams per cubic centimetre.
Now consider my house (ignore the yard). The built thickness is rubble 1 cm + foundations averaging out to 7 cm + floor 3 cm + ceiling 5 cm (including insulation) + roof 3 cm. That sums to 19 cm. Add an extra 2 cm to allow for internal walls and 3 cm for external walls. Total 25 cm. So even ignoring the much lower thickness of the yard their estimation of 200 centimetres is too large. (I have more to say about overseas below).
Check their density, timber 0.5 grams per cubic centimetre, concrete 2.4, gyprock 0.67, brick and tile 2.0, insulation 0.03. So it probably averages out to about 1.5, they’re right for Australia.
My house area is about 200 m^2, so multiplying it out (ignoring the yard) we have 0.25*1.5*200/3 = 25 tons per person.
Check their area. http://www.demographia.com/db-worldua.pdf
“In Paris, the relative areas of the core, built up urban and ex-urban metropolitan are 1:412:1386.” “In the United States, the 52 metropolitan areas with more than 1,000,000 population had only 19 percent of land in urban use, with the remainder of 81 percent being rural.” Not enough information, so let’s try another calculation route.
Australia is famous for its low population density within urban areas, and this contributes to a corresponding over-large built-up volume per person. From my admittedly limited knowledge of housing in London, Jamaica, Hong Kong, I’m going to estimate housing as 12 tons per person. With a world population of 7.4 billion that comes to 12*7.4 = 90 billion tons which is much less than the 17,400 billion tons for urban and rural housing in the Leicester University report. They’ve overestimated the total weight by a factor of 200 or so.
So my preliminary estimate is that their 30 trillion tons ought to be more like <1 trillion tons.