The most notable effect of the industrial revolution was

The total transformation of society. Example: Before the industrial revolution 98% of the human population worked in food production. Today, less than 1% of the US population is involved in food production. There are also dramatic statistics displaying the millions of pople since industrialization that have been lifed out of poverty. 'the most notable effect' depends on your values, ethics, bia, and opinion. There is no right or wrong to this question.

the world may never know