With reference to the article below, describe in detail the effect of producing more electric without a clean energy overhaul cars causing more pollution to the environment. Explain this using a positive sloped feasible frontier. Note, use key microeconomics theory under 'economics of the environment' to support your answer.

Pyakurel, P. (2019), 'Electric cars won't save the planet without a clean energy overhaul - they could increasepollution',The Conversation, June 03, available:https://theconversation.com/electric-cars-wont-save-the-planet-without-a-clean-energy-overhaul-they-could-increase-pollution-118012