If there are extra dimensions of space,the force of gravity would (in microscopic distances) increase way more than a factor of 4 times when the distance between masses is halved,which is the case in our three spatial dimensions. This makes the energy required to create a mini black hole fall in the TeV range ,possibly allowing particle accelerators/colliders such as the LHC and high-energy particles in the atmosphere to create one. Let's say,then,if in the case that there are mini black holes being produced naturally in the atmosphere,wouldn't the Hawking Radiation evaporated cause some detectable effects?
Take a look at Giddings, High-energy black hole production, https://arxiv.org/abs/0709.1107 , specifically the sections titled "Signatures" and "Cosmic ray production," and also Giddings' reference 33. Basically the answer seems to be that yes, it would be observable, and in fact the nonobservation of such events may by now be sufficient to rule out large extra dimensions. My understanding is that large extra dimensions are also pretty much ruled out at this point by LHC data. Others may be able to supply more recent references.