McDermott’s article in this issue of the Journal (The carbon footprints of obesity, chronic disease and population growth: four things doctors can do)1 calls doctors to arms, in the tradition of the famed 19th-century German pathologist Rudolf Virchow and today’s Medical Association for the Prevention of War, to contribute to a better world. Its writer draws attention to profound issues and is to be congratulated.

However, her recommendations are not so straightforward. Taken neat, the cure might do more harm than good. Consider obesity. Indeed, a recent article found that an obese population requires substantially more food energy than one with a normal body mass index distribution,2 although it is unclear whether the authors fully considered the shorter life expectancy and lower class-related reduction in other aspects of the ecological footprint of the obese. Elite sportspeople and military recruits also consume disproportionate amounts of food and other resources, but these harder targets were not mentioned. Singling out the obese seems simplistic and discriminatory.3

McDermott also advocates enhanced rights-based family planning, in rich and poor nations, as a means to reduce climate change. She discusses a recent report that found a high climate return for a low cost (that of funding family planning).4 As she mentions,1 the methods used in this thesis can be challenged, as it is obvious that growth in size of wealthy populations fuels far more climate change than does growth in size of poor populations, a distinction that is not clearly made. Criticising the poor for their population growth rate risks becoming another form of victim blaming. However, in the long run, slower population growth everywhere (especially in countries like Australia and the United States) will slow greenhouse gas accumulation. It will also enhance population health in low-income countries. McDermott also correctly advocates social, health and rights-based strategies to complement the largely technical and economic approach to climate change that is now dominant.5

It is easy to list actions that will improve global public health. However, compilers of lists need not only to prioritise their lists’ components, but also to describe how we can realise them. It is true that doctors are powerful role models, and the recent tentative steps by doctors and medical associations to recognise and address the health and other risks of climate change6 are important. However, the virtual absence of health (and the global population) as agenda items for the recent climate change talks in Copenhagen underlines how far there is to go.

It is also easy to call for “whole-of-government” approaches, whether to slow climate change, fix the obesogenic environment or to enhance equity. Easy to say, hard to achieve. A well known economic principle is the law of diminishing returns. A second ice-cream is not as tasty as the first. Less well known is the Matthew effect, or the law of increasing returns.7 This principle is a powerful impediment, not only to whole-of-government reforms, but to the transition to sustainability more broadly. Simply put, this principle describes how groups with influence are able to rig public opinion and legislate to benefit powerful minorities rather than the public good.8

The 18th-century philosopher Adam Smith warned against monopolies. The benefits to society and public health, including life expectancy, from reduced inequality are perennially rediscovered.9 Yet progress on reforming coal-fired electricity generation remains stalled both here and in Washington. Advancement of public goods such as public health and climate stability is thwarted by well funded and well organised lobbyists, who far outnumber public-good lobbyists.10 This illustrates an embedded Matthew effect, long operant in the US, and one about which Australia should not be complacent. Our long life expectancy might not always remain so.11

What is it, in this country, that prevents more extreme ideologies from taking root? The answer, in part, lies in our cultural norms and practices, such as our ostensibly “fair go” society, and in a reasonably free press. McDermott’s article1 and its receptive readers help counter the advantages of the powerful.

On reflection, it is not hard to see how the attitudes and norms of readers sympathetic to this analysis evolved. We all received a publicly subsidised education. Some of us descend from people who struggled for the opportunities and wealth we may now take for granted. Before our birth, large social movements worked intensely for a fairer world, using organised tactics that reduced the advantages, often hereditary, of those more powerful. Some of this resolution was forged in the trauma of World War II and the preceding Great Depression, helping to deliver the National Health Service in the United Kingdom and diluted copies of it elsewhere. Then, largely in the same English-speaking world, a less vigilant generation was seduced by the “fool’s gold” of neoliberalism, the conceit that marketism would deliver more public goods than would regulation.12

This false remedy has not only generated a decline in equity, but now threatens the whole of civilization.11 What can doctors do? Reflect and act, not just on the four themes proposed by McDermott, but on four hundred more. They can green their clinics, reduce their own footprint and join like-minded groups. There is no single recipe, but the principles of environmental sustainability, justice and commonsense are integral, as are courage and collaboration. Such action may work as a social vaccine against despair. Doctors, with other groups, may long postpone the world’s admission to intensive care.