It is also possible to terraform Venus, although much more difficult than for Mars.
We are facing an existential crisis in the form of climate warming on Earth that we are unable to address properly. The thing is, terraforming Earth is the easiest thing to do: we already live on it, it's already liveable. Mars, Venus or any other body in the solar system is magnitudes harder to transform on almost every aspect.
So unless humanity demonstrates it can tackle the easiest terraforming endeavour that be, anything else is firmly in the science fiction realm.