Demographic Transition From Rural to Urban Areas

1866 Words8 Pages
From 2000 until 2030 the urbanized areas will be nearly tripled1 because of the demographic transition from rural to urban. The use of dark building materials, such as asphalt and concrete, leads to a lower albedo in urbanized areas than in natural environment2, fostering local and global warming. In turn, the increase in urban albedo might support climate stabilization efforts3. Here, we investigate the potential effect of the increase in albedo in a representative set of European cities relying on instantaneous radiative forcing (IRF), urban cooling and the consequent effect on mortality, ozone formation and energy use. Apart from any geographical distinction, cities show that the increases in albedo in compact cities have a cooling…show more content…
Furthermore, we use the effect of the local variation in temperature on the heating and cooling degree days (HDD) (CDD) as a proxy for the effect on energy use and on the related greenhouse-gas emissions. Although these indicators are not representative of all t, they cover the most important ones. We calculate the potential effect of the local unitary increase in albedo on IRF – responsiveness (R) – for a sample of 145 cities and urbanized areas in three geographical areas: southern; central; and northern Europe (see Methods). Low cloudiness and high solar radiation make R in southern European cities two times higher than in other regions (see SI Table 1). The mean R in northern European cities is slightly higher than in central European cities – with values of 46 and 45 Wm-2 respectively (Fig. 1) – since cloudiness is lower in northern Europe. This result shows that climatological features would potentially make southern cities more effective that central and northern European ones in counteracting climate change. Apart from any geographical and climatological distinction, the peculiar size and the morphological characterization of each city may play a role in affecting IRF. We calculate the potential increase in average
Open Document