According to Wikipedia, planetary engineering is largely the realm of science fiction. We do not think this is the case. In our view we need to start seriously thinking about the science more seriously in relation to our role as custodians of this earth. Whether we like it or not as Tim Flannery says in his book "The Weathermakers", we are de facto planetary engineers.
Before we contemplate terraforming, by which a planet's surface conditions are altered to be more like those of Earth or caeliforming for the creation of an Earth-like atmosphere on other planets, we need to learn how to maintain our own planet as the healthy blue green globe that it once was.
Practices such as clear felling, ploughshare agriculture and irrigation are terraforming the planet is ways it was not meant to be changed. This burning of fossil fuel is caeliforming our atmosphere and changing our climate. We have much to learn. The key is to take nature as our teacher, embrace the principles of biomimicry/geomimicry and develop Gaia Engineering tececologies that undo what damage we have already done. It is time to contemplate our future and maintain spaceship earth.
 Flannery, T. (2005). The Weather Makers. Melbourne, Text Publishing.
 It was probably Buckminster Fuller who got us all thinking of earth as a connected independent entity requiring maintenance. His story is a fascinating one as throughout his life he was concerned with the question "Does humanity have a chance to survive lastingly and successfully on planet Earth, and if so, how?"