I don't exactly understand what you are saying but the report you linked shows that the non-reusable plastic bags reach the same negative impact on climate change 150 times faster than reusable cotton bags. How is that good?

When you talk about breaking even you are talking about reaching the same negative impact, I hope, because that's what the report is about.

They even spell out those negative impacts: ozone depletion, terrestrial eutrophication, freshwater eutrophication and water use.