"Ideas of terraforming Mars must be seen in a new light given the challenge revealed by global warming. Compared to pre-industrial levels, we have a 100 part-per-million (0.01%) CO2 problem in our atmosphere that has us completely stymied. Crudely speaking, Mars has a one-million part-per-million (100%) problem with its atmosphere. As much trouble as we are having mitigating climate change with unfettered access to all the resources on Earth, what hope would we have of turning around a place like Mars with no infrastructure to rely upon?"