If human population growth was net negative on resource utilization we wouldn't have population growth concurrent with more people rising out of poverty in the last 50 years than in all of human history.
Malthusian fallacy is no reason to not aim for human longevity. We need a better understanding of Xenohormesis to make it happen.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2504011/pdf/nihms60403.pdf