The human ecology of climate change - Climate Change: Biological and Human Aspects - page 377

population was still rising). With its 2010 forecast, the UN's Population Division
of the Department of Economic and Social Affairs increased its 21st-century pop-
ulation projections (Figure 7.5). This was in no small part because the mantra that
increasingly wealthy families have fewer children was found to be incorrect, due to a
ground-breaking paper by Mikko Myrskyla, Hans-Peter Kohler and Franceso Billari
in 2009. They found that while fecundity (which being demographers they called 'fer-
tility' even though couples' potential to have children was not in question) declined
with wealth in 1975, by 2005 some nations had become richer than the richest in
1975. The average life expectancy in countries with low infant mortality was 75 years
or more and per-capita GDP was in excess of US$25 000 (in terms of purchasing
power parity in 2000). These richer countries had larger families than those of the
richest in 1975. In short, once wealth exceeds a certain point, even though having
children is expensive they become more affordable.
This clearly is a double blow regarding anthropogenic climate change, as not only
do larger families generate more greenhouse gas than smaller ones, but affluent
families also produce more than their less-wealthy counterparts.
Figure 7.6b compares the geographic locations of the actual global population in
1950 with its anticipated locations in 2050. It is expected that by 2050 North America
and Europe will have a markedly smaller proportion of the total world population,
although in absolute numbers their populations will only fall marginally in the first
half of the 21st century. The largest increase in world population will take place in
regions with high poverty and unemployment (Raleigh, 1999). Irrespective of climate
change concerns, this means that resources will need to be used more effectively and
sustainably if human well-being is to be maintained without increasing environmental
impacts.
Meanwhile, in a number of developed nations the decline in fecundity of the aging
population has raised concerns about the size of the future economically active cohort
necessary to sustain a larger elderly population. In other words, the ratio of active
workers to retired people is decreasing. Just one instance of the policy response to
such concerns came in 2003 in France, where the government announced an 800

€

grant to each baby born to a mother from 2004.
The growth in developing nations' population has driven, and is expected to con-
tinue to drive, an increase in their contribution to global greenhouse gas emissions.
This will be explored in section 7.2, on energy.

7.1.4 Food

Agriculture enabled early civilisations to secure a regular surplus of food. Even so,
the negative pressures of disease on the population remained, albeit in a changed
manner: the gathering of humans into larger local population centres increased the
opportunities for disease transmission even if an improved diet reduced disease
associated with poorer nutrition. Consequently, despite an agricultural surplus there
was not entirely a commensurate increase in the population of early civilisations.
Indeed, the agricultural surplus of early civilisations was not great, and although
more of this surplus could have supported more children, hence greater population
growth, it was instead used largely for other purposes. For instance, Egypt during