@Nichol A possible Kessler Syndrome is definitely an issue. LEO is however close to earth and things will de-orbit within months or several years. It will 'mostly' clean itself up. Pollution on earth happens mostly in the lower parts of the atmosphere. We don't know enough about the long-term effects of pollution in the upper atmosphere. I am not an expert on this topic but other people here know all the ins and outs. @sundogplanets @Olson @julescelt01 @markmetz @river