Academic journal article Bulletin of the World Health Organization
Needed: Tenable Values or Five to Ten More Earth-Sized Planets
DA Doesn't the real threat to health now all come down to unsustainable levels of production, consumption and pollution?
JL Yes indeed, but it depends on many factors, such as whether the economy is industrial or agricultural, affluent or subsistence-level, the size of the ecological footprint made by urban areas, the sustainability of essential resources.... We would need several earth-sized planets to support, even for a short time, the earth's present population at the present consumption and pollution-generating levels of the USA -- probably between 5 and 10 planets.
Since we have only one, and its nonrenewable resources, especially water for irrigation and drinking, are already severely strained in many parts of the world, and human actions are rapidly reducing these resources, I think current estimates of sustainable human numbers should probably be revised downwards. Currently, I think, we expect to have a global population of 10 billion before 2100. Of course demographic projections are notoriously fragile, but I think the irresistible force of demographic and industrial expansion will meet the immovable object of limited non-renewable resources in the lifetime of most people now living, i.e. this side of 2050.
DA And then what? A big bang?
JL What that collision will produce is a whole other kind of question. Armed conflict is one pretty predictable consequence. Another is economic decline and infrastructure decay, with far-reaching consequences, including deterioration of public health services. Whether we have an explosion or a collapse, or both, will depend on the wisdom of national and international leaders in many fields -- politics, industry, security, and, of course, health. I could go on, but maybe this is enough.
DA But doesn't this mean that if we do the right thing in the traditional and obvious ways, of saving lives and reducing poverty, we are actually doing the wrong thing, by putting more strain on our common life-support system?
JL It's a false antithesis. There is no contradiction between the aim of public health to prevent disease and premature death, and the other aim of husbanding the earth's resources. If promoting health and preventing disease and premature death lead to a surge in population (and there's some doubt about whether they do) then this is a temporary and transient phenomenon, as a review of historical demography soon reveals. …