The polarity and longevity of the debate about the ills of a growing population are well captured by Laurie Mazur:
Malthus' intellectual progeny still blame human numbers for poverty, resource depletion and a host of social problems; many of Marx's inheritors think population issues are, at best, a distraction from dealing with core issues of inequality and, at worst, a plot against the poor. In this binaiy discourse, one can care about social justice, or about population - not both.1
In its manifestation as an argument about numbers of people on the planet and environmental degradation, the debate is familiar to environmental lawyers. Population and the environment is moving up the political agenda: the twenty-ninth (and final) report of the Royal Commission on Environmental Pollution (RCEP), Demographic Change and the Environment, was published in Februaiy 2010.2 One of its key findings was the need for a more measured and open debate on population and the environment. The Royal Society is to report on People and the Planet in 2012;3 a Foresight report is being prepared on Global Environmental Migration.* Far from being the last taboo, as is sometimes claimed (and as it may once have been), population growth is rarely out of the news for long. Whilst there is something almost menacing about a claim that the 'optimum' population for the UK is between 17 and 27 million,3 refusing to think about population because of the company we might keep would be short-sighted.
Consistent with its prime remit, the RCEP concentrated on UK demography. Historically high levels of immigration from new members of the EU, together with increases in fertility rates and greater life expectancy, have led to considerable attention being paid to increasing population. This has led to perceptions that the country is 'full'; that maintaining environmental quality depends upon reducing the size of the UK population. The RCEP is convinced that this is a simplistic response, most importantly because of how we live, our consumption levels, have a far greater impact on the environment than numbers of people. Furthermore, the size of the population would be close to impossible to change - even if we were able, let alone willing, to reduce the birth rate (already below replacement rate6), stop further increases in life expectancy, and achieve zero net migration (with far more significant political and economic implications than could be justified by uncertain environmental impacts), there would be little reduction in population over the next forty years.
That does not mean that population is unimportant. Numbers are not the only interesting thing about population. The significant demographic trends identified by the RCEP, in addition to changes in population numbers,8 are: the changing age structure of the population (an increasing proportion of over-65s and over-85s); increasing numbers of households (because of the decreasing average size of each household, as well as a rising population); and the distribution of population around the UK, with high numbers in London and the south-east.9 Whilst a great deal of data is available on these trends, they remain, in at least two respects, extremely difficult to pin down. First of all, looking forward depends on projections rather than predictions,10 with associated complexities and uncertainties. Secondly, national trends can disguise immense variation at the regional and even local levels, with some areas experiencing population growth, some a declining population, some a large change in the age structure of the population, others not.