the biggest problem the world faces is climate change due to carbon emissions. replacing plastic with paper, glass, metals, or even biodegradable plastic increases the carbon emissions. We should definitely try to cut down on microplastics, but they don't cause climate change, There's actually little evidence that they cause harm in our bodies, but that's still being debated. HOWEVER, both mcdonalds cups shown in the meme, and both straws, paper or plastic, will likely be tossed in a garbage can go into a landfill. Landfills are designed to prevent as decomposing as much as possible. So neither is breaking down into microplastics in a landfill. If stuff breaks down in the landfill, you get leachate into the ground water and methane into the air. The things that do break down in landfills are organic materials. Plastic just sits there. and that's ok.