TRANSHUMANISM
Aided by transhumanist technologies, it is expected that people would be able to live longer, and hence an expected overall increase in the global population. This would mean a greater need for food, energy and living space. More goods will also have to be produced to sustain a longer-living population as well. This may lead to a Malthusian catastrophe, where population growth outpaces agricultural production.
Environmental
However, one should be open to the possibility of transhuman being biologically modified to live in outer space colonies. Differences in conditions such as atmospheric pressure, atmospheric content and gravitational force, that may be inhospitable to an unmodified human being. This would free up space and resources on Earth, and may even bring us to the future possibility of humans becoming a spacefaring species. This would of course lead to many implications, and whether such people should even be considered transhumans anymore or a different species entirely (posthumans).
Illustration of the Malthusian Catastrophe. Reproduced from Green (2006).
Reproduced from NASA (2004).