What is a disadvantage of science?

None. Whether some scientific knowledge is put to good or bad use is the responsibility of the human beings making these decisions, not of the science. Moreover, often the distinction between "good" or "bad" is a subjective decision, not an absolute. And, it may be that a decision that seemed to be good at one time may be considered not so good or even bad, at a later date. Using fossil fuels for energy and other chemical products such as plastics, must have seemed a no-brainer even 50 years ago. But global warming has made that decision appear distinctly unsound. Ocean fishing using trawlers seemed a good idea initially until fish populations started to dwindle. I suggest that in both these examples, it is not the application of the science that is At Fault but the intensity with which it was executed.