Interview

Needed: tenable values or five to ten more earth-sized planets

John Last interviewed by Desmond Avery

John Last has worked as a ship's surgeon on intercontinental voyages, an epidemiologist and university teacher in Australia, Canada, the United States and the United Kingdom, and a consultant in numerous developing countries. He has won prestigious awards for his contributions to epidemiology and preventive medicine. Among his current preoccupations is the blindness of the media, the general public and decision-makers as to what is really at stake globally for human health now and in the coming years.

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 non- renewable 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.

However, reducing poverty does seem to be connected, in our globalized economy, with rampant, strident hucksterism, and unrestrained consumerism. Everyone wants their own all-terrain vehicle and jet-ski and 3-car garage, etc. Globalized markets are thrusting energy-intensive products at us from all sides. I haven't been in China for almost 20 years, but the TV pictures I see of crowded shopping malls and roads filling up with cars and trucks strongly suggest that rising incomes there have led to unrestrained consumerism.

There is a prevailing view that perpetual economic growth is both possible and desirable. The reality is that it is no more possible than perpetual motion; furthermore, economic growth is increasingly being achieved at the cost of finite non-renewable resources. We will leave a resource-poor world for our descendents because of this.

The transnational corporations would like the whole world to buy, buy, buy, to become addicted to shopping, and of course to the internal combustion engine to get them to the shopping malls. This is a far more harmful addiction than even tobacco.

DA And more unstoppable, it seems to me. Do you think anything can be done to change it?

JL Yes, I do. There are five essential components required to solve any and all health problems and they have to be mobilized to do this: (1) awareness that a problem exists; (2) an understanding of its causes; (3) capability to tackle those causes; (4) a sense of values that make it clear that the problem matters; and (5) the political will to take the necessary but probably unpopular action.

These five components were all in place when the sanitary revolution transformed population health in the industrializing nations of the late 19th and early 20th centuries. They are falling into place in the control of tobacco addiction in many nations now, and in confronting impaired driving, substance abuse, domestic violence, and several other formerly intractable public health problems in the most progressive nations. We won't get far towards achieving sustainable global life support systems – and sustainable population health – until these five components are all in place. The most challenging are values and political will. Somehow we have to cure ourselves of addiction to fossil fuels, and this requires a change in our values, and enormous political will.