The carbon dioxide from climate change (global warming as it is called in the press) cools the atmosphere causing the thermosphere to contract? This would result in many more collisions and would be a major hazard for the ISS and other satellites.
The thermosphere is the outermost layer of the atmosphere. This layer would contract if carbon dioxide built up. This means that the International space Station and many other satellites that orbit in the thermosphere would be affected.
The effect would be to reduce atmospheric drag on satellites. This drag causes the satellites orbit to change which draws the satellite closer to the Earth. The cooler troposphere and the reduced drag means that space junk will accumulate quicker than today.
This will obviously create more collisions and more near misses. On Earth though there would be no increased risk as satellites wouldn’t fall to earth so often. The only way that Earth would be affected would be that if satellites were lost then some services would be lost.
There is one advantage to this though and that is that satellites would no longer need to boost themselves back into orbit as often as they are doing at the moment. This would mean a reduction in the fuel used and therefore the fuel needed to be transported up into orbit would be less.