How the re-entry casualty risk could be impacted by future launch traffic?

The launch of mega-constellations in low LEO, together with the disposal of satellites from higher orbits, will entail a significant increase of the kinetic casualty risk in the coming years. The analysis based on the last 12 years, i.e. the time period preceding and partially overlapping such transition phase, confirms that the global casualty probability is still quite low, of the order or less than 2-3% per year. However, if another 4000 or 20,000 satellites were to re-enter without control every year, the probability of having at least one casualty would become about 30% and 80%, respectively, probably reaching unacceptable values for safety on the ground and in airspace. In order to minimize such risk, the components of a satellite should be designed and made of materials able to maximize the probability of being burned upon re-entry into the atmosphere. However, also this strategy might not be the most appropriate over relatively long periods of time and for thousands of re-entering objects, due to the release, in the upper atmosphere, of large quantities of chemical substances having a negative impact on the environment. There is therefore no simple way to address this issue, but it will still be essential that these problems are well analyzed and discussed to avoid running into an irreversible situation, where the re-entry risk is at that point too high to be controlled.