This is a tough one, to find links in these processes but I will give it my best shot.
Plastics are usually made from the petrol/diesel manufacturing process, more and more bio-based or environmentally friendly plastics are been made and the less petrol/diesel that is been manufactured the more bio-based plastics, so in that way less petrol/diesel would result in fewer emissions and therefore less heat in the atmosphere. The plastics will just be made out of different material as time goes on, so no real link in plastics to heat, it is only the process by which plastic is currently made.
Soil pollution can cause plants to die off, plants take in carbon dioxide and give out oxygen, by doing this they also less to reduce the heat in the atmosphere. Widespread Soil pollution would, therefore, cause a heating up of the atmosphere and reduced oxygen.