This video explains the opportunities and concerns of GMOs in a very nice manner. I personally believe, that GMOs have the potential to solve many problems our society is facing (world hunger, climate change, health). I do however have one major concern and this video also mentions it briefly.
And that is the fact, that our food supply (as is everything else) is governed first and foremost by the profit. Which means that companies are inclined to make decisions that are beneficial to the profit margin, but might be not so beneficial to our health, or the environment. There is nothing new in that – with all the pesticides, added sugars and other harmful ingredients, decreasing nutritional value, the way our food is produced with disregard to the environment – all this has been ongoing for decades (despite all the evaluation agencies) and it might as well continue with the GMOs. And I fear that consequences with such (profit) mangling with the GMOs could be far more dangerous and harmful than what we are experiencing (consuming) now.