Civilizations have overused their resources before, and collapsed or moved on, but never on a scale remotely resembling the present threat, and now the Earth is full. There is nowhere to move. There is a fatal disconnect between our national policies, which are geared toward faster economic growth, and our growing scientiﬁc understanding of the limits to growth. This country and much of the world are driving into those limits, and only a fundamental rethinking of growth will spare us that future.
Even those who are not wedded to growth often try to solve our problems piecemeal with technical ﬁxes. That is tunnel vision. Such “ﬁxes” alone will not cure the resource and environmental threats generated by past and continuing growth. We face interactive problems: the energy transition, climate change, intensifying fresh water shortages, and present and prospective shortfalls in food production. Together, they warn us that current population and consumption levels will not be supportable in the future.
We should indeed seek technical ﬁxes, but we must begin policies to reverse the growth of demand, and that begins with population and therefore – in the United States — immigration policy. Barring a dramatic change of direction, the Census Bureau projection of 420 million Americans by 2050 is – from past experience — likely to prove much too low. Particularly if the nation adopts the immigration amnesty proposals being made by leaders of both political parties, our population may well rise to 500 million by then, and keep growing.