Good job bringing this to light. People won't realise how huge the problem is and municipalities are woefully ill equipped to...
Agreed; mining can never be sustainable, but then how do you get the metals to make all the things you need in the course of...
Very good piece.
John Matese and Daniel Whitmire of the University of Southwestern Louisiana, Lafayette, in a recent paper say that tide-like variations in the pull exerted on the orbit of the solar system by the rest of the galaxy causes comets to pummel Earth once every 30 million years. Most comets orbit the sun in the Oort cloud, which lies 100,000 times farther out than the Earth. If the orbits are disturbed, some comets may fall into the inner solar system and crash onto Earth.
The team has calculated orbits into which comets from the Oort cloud could be tugged by the tides. There are two tidal forces, one which tugs matter in a direction perpendicular to the plane of the galaxy, and one -- the radial tide -- which pulls toward the centre of the Milky Way. Of the 84 comets studied, one-third are in orbits that had been influenced by the radial tide while in the Oort cloud. The probability that this could occur by chance is only two in a million (New Scientist , Vol 152, No 2062).