How healthy is the world? (Troubled planet).

In The Skeptical Environmentalist I set out to describe the entire state of the world in a single book. (1) This was by no means easy, and so I was a bit hesitant when the BMJ asked me to do the same again--only this time in 1500 words. So how can the true state of the world be reduced to 1500 words? Of course, it cannot be. But by relying on official statistics, global trends, and long term tendencies (what I usually refer to as fundamentals), we can draw a reasonably good picture. However, not everything can be fitted into this picture, and this article will focus on human welfare.

Measuring human welfare is complex because it consists of a myriad of inter-related subjective and objective factors. I will therefore focus on international acknowledged objective indicators of human welfare such as life expectancy, prosperity, and the fulfilment of basic needs.

Life expectancy

One of the central aspects of human welfare is life itself. Life expectancy is a proxy for the general state of health, but it also possesses an intrinsic value. Figure 1 shows the remarkable increase in life expectancy for the developing world over the past 50 years, from 41 years in 1950 to 64.7 years in 2002. For the developed world, the progress has been more modest because life expectancy had already soared at the beginning of the last century. The current life expectancy for countries in the Organisation for Economic Cooperation and Development (OECD) is 76.8 years. (2)

[FIGURE 1 OMITTED]

Figure 1 also shows the expected development in life expectancy over the next 50 years, incorporating the adverse effects of AIDS and HIV. By 2020, life expectancy in the developing world will pass the 70 years barrier, causing the world's life expectancy to continue to climb. The United Nations' populations division projects that in 2080, the world's life expectancy will be more than 80 years. (3)

Prosperity

Income is a good indicator of welfare because it expands the range of opportunities open to people and allows them to live a better life. Although wealth might not always make you happier, it at least ensures freedom from famine and material deprivation--issues that play a huge part in many people's lives. The gross domestic product per capita (in 1985 power purchase parity dollars) has increased by over 200% for both the developed world and the developing world over the past 50 years (fig 2).

[FIGURE 2 OMITTED]

The increase in gross domestic product per capita has been accompanied by a fall in worldwide poverty. According to the United Nations, "in the past 50 years, poverty has fallen more than in the previous 500." (4) Whether inequality has also fallen is more debatable, since inequality is highly sensitive to the choice of population quintiles and the method of comparison. As for the future, all official international organisations predict an exponential rise in worldwide income and decreasing inequality as the growth rates of developing countries outpace those of industrialised countries in next 50 years. (5-7)

General increase in welfare

Other improvements in welfare during the past 50 years include heightened educational levels and literacy, more political …