I would love to go back in time, even just as an observer who couldn't modify the past. To be clear, I don't believe time travel is physically possible despite

I would love to go back in time, even just as an observer who couldn't modify the past. To be clear, I don't believe time travel is physically possible despite anyone's mental gymnastics with negative mass and/or energy. This is purely fanciful. I bring this up because this story reminds me of the history of trees. Nowadays, if you chop a tree down and leave it there within a year or two (depending on the size of the tree) it'll basically be gone, largely due to microbes that have evolved to consume mob. They're kind of wild to look at (there are Youtube videos). The ancestors of modern trees first appeared (IIRC) ~200-250M years ago. These apparently would've been odd to us. Small root systems that (apparently) were likely to topple over. But those microbes that now exist to consume wood didn't exist then and didn't exist for another ~60M years. This BTW is where 95% of the coal comes from. But what must this world have been like? Did tree trunks literally just lie there for tens of thousands of years until they probably were buried? Flowering plants didn't exist either. Anyway, I'm not sure what to make of microbes eating plastic. I mean is this a good thing? Obviously getting rid of nano-plastics would be good but what else would they do? My understanding is that the energy density of plastic is really high too. It's the same reason microbes don't eat concrete.