The Impending AI Revolution and the Disruption It Will Cause
The AI revolution is causing a massive amount of disruption, and it is interesting to think about the industries that should have been disrupted by existing technology but haven't been. The tweet in this blog post was an example of this, as it made an incorrect assumption about the number of satellites in orbit.
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Prof Michael E. Mann
Scientist/Author; Pres Dist Prof/Director Center for Sci, Sustain. & the Media, U. Penn; Nat Acad of Sci.; Tyler Prize; Mastodon: @MichaelEMann@fediscience.org
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Congratulations--you just won stupidest tweet of the week (just under the wire too!). https://t.co/Mxd5vAUuEK
— Prof Michael E. Mann (@MichaelEMann) March 3, 2023 -
Let me explain. 🧵
— Prof Michael E. Mann (@MichaelEMann) March 3, 2023
Surface area of Earth is ~5 x 10^6 km^2 (https://t.co/gGhlVefhLR) -
There are currently ~7,000 satellites in orbit around Earth at any time.https://t.co/r2B17UM7Mm
— Prof Michael E. Mann (@MichaelEMann) March 3, 2023 -
Cross-sectional surface area of a VERY LARGE satellite (including solar panels) would be 2500 sq meters:https://t.co/gaZMzMus23
— Prof Michael E. Mann (@MichaelEMann) March 3, 2023 -
That amounts to a total cross sectional surface area of ~18 km^2.
— Prof Michael E. Mann (@MichaelEMann) March 3, 2023 -
That's a fraction of 100 x (18/5x10^6) = 0.00035%.
— Prof Michael E. Mann (@MichaelEMann) March 3, 2023 -
Making the extremely generous assumption that each satellite reflects all incident solar insolation back to space, that amounts to a change in Earth's planetary albedo (reflectivity) of 0.00035%.
— Prof Michael E. Mann (@MichaelEMann) March 3, 2023 -
That's a change in Albedo (alpha) from ~0.30 to ~0.3000035. Using a very simple energy balance model, T^4 varies as 1-alpha (which goes from ~0.70 to ~0.6999965). https://t.co/WPdA4vuMY5
— Prof Michael E. Mann (@MichaelEMann) March 3, 2023 -
That means temperature T of Earth decreases by a factor of roughly (0.6999965/0.7)^(1/4) = 0.99999874, or from a global average temperature of 289K (16C) to 288.99964K (15.9996C).
— Prof Michael E. Mann (@MichaelEMann) March 3, 2023 -
That's a cooling of 0.0004C, which is dwarfed by the warming (~1.2C) that has already occurred, and not even remotely within the measurable tolerance of estimated global average surface temperature.
— Prof Michael E. Mann (@MichaelEMann) March 3, 2023