CO2 is just one of them, you have a bunch of other gases responsible for climate change like Methane that are way worse than CO2.
I’m surprised this is still on the EPA website Overview of Greenhouse Gases | US EPA
However, plastic are affecting wildlife and, indirectly, also affecting climate. Plastics floating on the ocean are incorporated into the food chain. They also block light and affecting plankton and the other animals they subsequently feed.
Great Pacific garbage patch
The Great Pacific Garbage Patch (also Pacific trash Vortex and North Pacific Garbage Patch) is a garbage patch, a gyre of marine debris particles, in the central North Pacific Ocean. It is located roughly from 135°W to 155°W and 35°N to 42°N. Spanning from the western coast of North America to Japan.(Great Pacific Garbage Patch National Geographic 2023) The collection of plastic and floating trash originates from the Pacific Rim, including countries in Asia, North America, and South America Des...
http://www.environment.gov.au/marine/publications/impacts-plastic-debris-australian-marine-wildlife
Everything we can do to overturn this is welcome. Personally I think both are necessary, taking care of the ocean and of the atmosphere are equally important.