Let me start by saying that I am a huge proponent of space travel and exploration. I admire Mr. Musk for his ambition and drive. However, in this pursuit I think he is misguided. He has stated that one of the main reasons he believes humans need to colonize another planet is fear of how badly we have destroyed the earth. In the future, he argues, humankind must find an alternate home. The earth simply cannot sustain us. Mars is the next best option.
Sounds great and in principle and I generally agree with his philosophy. However consider the following. Mars has virtually no oxygen while the earth currently has plenty. Mars is continually bombarded by deadly radiation while the earth is not. Mars has no easily accessible drinkable water while the earth has (with several notable exceptions) plenty. Mars has almost no atmosphere. The earth still has a very plentiful and pleasant one. The gravity on Mars is at the very least sub-optimal for human life. Earth’s gravity is ideal for us. Mars has no (or very little) microbial life while the earth has a teeming population of microorganisms the vast majority of which work to our benefit. Mars has no plant or animal life. The earth has an abundance of both.
Yes we have misused and abused our own planet earth but it is just not true that we need to find an alternate home at this time. Perhaps someday if we continue to destroy our natural resources the need for another planet to colonize will be greater. At this time, however, we do not. The push to populate Mars is nothing more than a rich mans fantasy right now. The resources used in this effort would be much better spent fighting to improve our situation on earth while we continue to expand our existing Mars exploration and mapping program with robots and unmanned exploration missions.