The world of Pandemonium is a world in another universe where humans may exist, that is gravitationally connected to Earth in our universe. Over the course of history since the big bang, these universes have periodically collided, transferring organised matter from one to the other, including humans. Now these two universes are about to collide again, in present day Earth and Pandemonium.
To explain what the collision is like, to use a two-dimensional analogy, think of each universe as being like a sheet of wrinkled crepe paper, and when they collide, it is as if the two sheets of paper were laid on top of each-other. At the places where the two sheets touch, matter may cross from one universe to the other.
In essence, when the universes collide, wormholes will appear throughout the parts of the two universes that are in contact with each other, ranging in size from a few metres to a few hundred metres across. Individual wormholes may occur as close to each other as several hundred metres apart, but most will be at least several kilometres apart, and some wormholes may be up to fifty kilometres away from any others. At or below ground level or within a few hundred metres of the ground, the average distance between any two wormholes may be around 5 kilometres, but rapidly increasing in distance as altitude increases to several thousand kilometres between wormholes at the Kármán line, tens of thousands of kilometres apart in interplanetary space, and hundreds of thousands of kilometres or more apart in interstellar space.
Wormholes are readily visible due to the optical distortion effects around their fringe and visibility of the space in the universe on the other side.
The wormholes will have a slight repulsive effect that means that unless an object is moving with sufficient energy in the right direction, more or less directly toward the centre of the wormhole, it will tend to be pushed away from the wormhole. Matter that passes through the wormholes will tend to do so in its entirety, unless the matter in question is a body of liquid or gas bigger than a wormhole. For a solid object to be torn apart in a wormhole would require a collision with the wormhole at least energetic enough to tear apart the object regardless of what it collided with, and a wormhole of insufficient size to allow the object to pass through in its entirety. When the wormholes appear, they won't generally cause significant damage to static infrastructure. On a human scale, if a person was to deliberately try to force themselves through a too-small wormhole, they might suffer bruising as if they had tried to force themselves through a too-small opening in a solid object. The more likely outcome if a person wasn't trying to get to the centre of the wormhole is that they would be harmlessly diverted to one side.
Because the two universes have been colliding at decreasing intervals and for increasing amounts of time across their existence, and they are gravitationally connected, wormholes will open between roughly equivalent places, underground to underground, ground to ground, air to air, space to space and so on. There may be some slow atmospheric or hydrological exchange where there are significant pressure differentials.
Because of the laws of relativity, the wormholes between these two universes occur relative to significant objects within them, i.e. stars and planets. This means that the movement of these objects will carry the nearby wormholes along with them. Since Pandemonium and Earth are 'co-located' and are in effect moving along the same orbits at the same speed and the same rotation, the wormholes will be stationary relative to both of those worlds.
At the 'moment' when the wormholes appear, they will all appear at a small size and increase in size rapidly over the course of a few minutes, and after that, they will fluctuate slowly and more or less simultaneously in size to about +/- 20% of their initial inflated size over the course of around a month following a sinusoidal pattern.
Given that background, I now come to my question:
Given that these wormholes will appear all across the world more or less simultaneously, including in our cities, how much of a disaster will their appearance cause?
I'm not concerned with the political situation, only the emergency services situation. As I haven't written about the society on the Pandemonium side, responses need only consider the Earth side.