The human enterprise is in overshoot; we exceed the long-term carrying capacity of Earth and are degrading the biophysical basis of our own existence. Despite decades of cumulative evidence, the world community has failed dismally in efforts to address this problem. I argue that cultural evolution and global change have outpaced bio-evolution; despite millennia of evolutionary history, the human brain and associated cognitive processes are functionally obsolete to deal with the human eco-crisis. H. sapiens tends to respond to problems in simplistic, reductionist, mechanical ways. Simplistic diagnoses lead to simplistic remedies. Politically acceptable technical ‘solutions’ to global warming assume fossil fuels are the problem, require major capital investment and are promoted on the basis of profit potential, thousands of well-paying jobs and bland assurances that climate change can readily be rectified. If successful, this would merely extend overshoot. Complexity demands a systemic approach; to address overshoot requires unprecedented international cooperation in the design of coordinated policies to ensure a socially-just economic contraction, mostly in high-income countries, and significant population reductions everywhere. The ultimate goal should be a human population in the vicinity of two billion thriving more equitably in ‘steady-state’ within the biophysical means of nature