I think that at this point everybody understands, at least the basics of, climate change and global warming. We know that our planet (Earth) is getting hotter. I think most people can also safely assume that when a rocket is launched it releases carbon dioxide, which traps heat and warms Earth. We know this is bad, however, the amounts of carbon dioxide released are so minuscule that they have almost no effect on our environment.
The real environmental issue with launching rockets is that inside the plume of exhaust that a rocket leaves in its wake are small pieces of soot and a chemical called alumina. These chemicals eventually get injected into the stratosphere and break down the ozone layer, the ozone layer is what protects Earth from the Sun's harmful radiation. Allowing the ozone layer to break down means we may have to eventually evacuate Earth and move to another planet, however, to find another suitable planet we would have to venture into space once or many more times, which causes the release of more and more soot and alumina which would break down the ozone layer and speed up the time it will take before it becomes too dangerous to live on Earth.
Unfortunately, not many people know about these separate issues with launching rockets and so will continue to send rockets into space and shrink the time we have left to live on Earth.