"Unprecedented scale" refers to something that is happening or being done at a level that has never been seen or experienced before. It means it's happening on a much larger or greater size than anything that has come before it. Full definition
In my brain, I know that my government and other governments are causing pain and suffering on unprecedented scales, even including the 20th century. (sbnation.com)
It helps us to learn at unprecedented scale and speed. (inc.com)