Prove that capitalism won't cook us all to death first.
Proving negatives is fun.
Solar energy, geothermal, nuclear , wind, etc
Car emission rates have been declining with new and more sophisticated models coming out, especially hybrid cars or electric cars.
Your turn, tell me how a leftist "utopia" wont become totalitarian, or violent.
Communists dont believe in private property, therefore they will steal from those that do, and theft to my knowledge always happens with force and violence.