I would like to use the verb realize in a sense of " to become real" or "to happen" in active voice. Nonetheless, dictionaries use it in passive voice in this sense.
Although global warming does not happen by itself, I wonder if I could use the word to realize in active voice just as the word to happen.
Global warming is realizing at such a slow pace that we only began to notice it years later it began.
Global warming is happening at such a slow pace that we only began to notice it years later it began.
Another sentence could be :
Unfortunately imminent fiscal crisis is realizing but there are a few things we can do about it.