What impact will the US pull-out from the Paris Agreement have on climate change?

I hope that it will encourage others to do the same.

I hope that it will help persuade others that there is nothing that mankind has done or will do (short of nuclear Armageddon) that will affect the climate.

I hope that the people who publicly have promoted man-mind climate change will take their research away from politics and put it back into the laboratory until they know how the climate works. Because they don't at the moment.

Germany - a major supporter - is pulling back from its commitments.

It seems that almost no countries are making any substantial "progress" - see http://climateanalytics.org/latest/climate-action-tracker-launches-new-rating-system

There is no one to enforce the Paris agreement anyway. It seems to me that the Paris agreement was a headline seeking event that ended without substance. Yet another complete waste of money for something unproven. Countries will gradually find reasons for not comforming to the Paris agreement, and the whole mess will fade into blessed history.