Demography plays an important although often hidden role in contemporary global change. In this chapter I examine some of the ways in which demography is entangled in certain significant shifts in the global order: climate, political economy and geopolitics.

DEMOGRAPHY AND CLIMATE CHANGE

Because of the importance of human activity in shaping earth systems, some commentators have described a new geological age, the Anthropocene. Increasing population with growing per capita environmental impact has transformed the world. We have cleared the forests, reduced habitats and diminished biological diversity. And because of our use of fossil fuels, we have modified the climate. Our planet is warming to such an extent that we can identify a new subcategory of the Anthropocene: the Pyrocene.

Demography plays an important role in this new era. In one sense it has created the new era. The steady increase in global population in association with a large and an increasing per capita carbon footprint has generated enough greenhouse gases to change the climate regime to one that is warmer and more vulnerable to extreme climate events. The 100-year flood turns into a five-year flood, punishingly hot summers become commonplace and the once in a generation hurricane becomes a more regular event.

The current demographic distribution of population was based on a different climate regime. A world in which major floods were irregular events and extreme warming in many regions was rare. The current population distribution is now faced with a different set of conditions. These include but are not limited to the very rapid warming in cold latitudes, extreme warming in the mid-latitudes and a greater risk of sea level rise and flooding in river basins and coastal regions around the world. The current global population distribution was better suited to past climate regimes and is now faced with greater vulnerability because of the greater frequency of extreme weather events. It has resulted in various forms of climate refugee population movements. In Bangladesh, for example, residents are being flooded out from many of the rural areas by more powerful monsoonal rains and greater glacial melting from the Himalayas washing away their farmland.