About 3,000 metric tons in LEO[0]. Don’t worry about mass above LEO, as there’s far less up there and it’s not decaying any time soon. LEO velocity is about 8k

About 3,000 metric tons in LEO[0]. Don’t worry about mass above LEO, as there’s far less up there and it’s not decaying any time soon. LEO velocity is about 8km/s. Plugging that in to mv^2 gets you about 200 trillion joules of kinetic energy. Assuming the chemical (burning) energy contained in space debris is negligible, that 200 trillion joules is the maximum energy you’d transfer to the atmosphere if all this debris suddenly deorbited. The sun, in contrast, transfers about 430 quintillion joules per hour to the earth[1]. So the kinetic energy of all LEO mass is about a millionth of the energy the Earth receives from the sun every hour. Prob not a heating concern. (Please check my math. This was a wonderful nerd snipe but I did it on my phone while defrosting chicken nuggets). 0: https://www.sciencedirect.com/science/article/pii/S0094576521001430#:~:text=The%20total%20mass%2C%20about%203230,of%20debris%20from%20collisional%20breakups https://www.sciencedirect.com/science/article/pii/S009457652.... 1: https://thatsbyers.com/blog/how-much-energy-does-the-sun-really-provide#:~:text=According%20to%20the%20U.S.%20Department,40%20billion%20Joules%20of%20electricity https://thatsbyers.com/blog/how-much-energy-does-the-sun-rea....