Probably effectively about as much as a satellite exposed to a 3,000 degree celsius reentry in an Oxygen rich atmosphere. These are flammable substances that either burn or are destroyed outright by extreme heat. This is my point. People dont really know what they should be worrying about. High sulfur oil burned by cargo ships because its dirt cheap and unregulated is worth worrying about. CO2 emissions are worth worrying about. We are on a path to making this planet uninhabitable with how slow we are tackling global warming. The oceans are becoming progressively more anoxic and animal biomass has collapsed by over 70% in the last 50 years. We are causing enough damage to the planet that we are effectively causing the 6th major mass extinction. But it isnt because of the trivial amounts of satellites that burn up in the upper atmosphere. Its due to things that no one seems to give a shit enough about to actually stop. Which is sad because we have been successful in some attempts to restore the environment. The Montreal Protocol for example significantly curtailed CFC production which does seem to be allowing the Ozone hole to heal slowly over time. Regulations meant to reduce Nitrogen Oxides in the US worked really well with a cap and trade system. We have the capability to tackle problems if we as a species wish to do so. The problem is that we would rather focus on small things and not tackle the problems that are going to make this planet a former host of intelligent life.