By Mia Rabson THE CANADIAN PRESS OTTAWA- Negotiators from 176 countries will gather in downtown Ottawa this week for the fourth round of talks to create a global treaty to eliminate plastic waste in less than 20 years. Ottawa is hosting the fourth of five rounds of negotiations, with the aim of finalizing a deal by the end of the year. The proliferation of plastics has been profound, as it is a preferred material largely for its affordability and longevity. But that also means it never goes away, and the impact on nature and growing concerns about human health are leading a push to get rid of plastic waste and eliminate the most problematic chemicals used to make it. Canada’s environment minister, Steven Guilbeault, played a crucial role in getting…