Urban sprawl in Central and Southern Chile

Urbanization constitutes worldwide a major and growing driver of global change (Zhu et al, 2012 and references therein), and so is also the case for urban centers in Chile and elsewhere in South America (Gallardo et al, 2012). Urban centers affect the regional climate in several ways. They perturb the atmospheric flow and significantly alter the surface energy and moisture balances (e.g., Hidalgo et al, 2008).

uch230615Large cities concentrate population, transportation needs, energy and goods consumption, etc., leading to large emissions of CATs.

 These emissions affect the radiative balance, either directly or indirectly, regionally and globally (e.g., Butler and Lawrence, 2009). The climatic impacts of cities in Central and Southern Chile are further enhanced by the nearness of coastal upwelling areas allowing changes in cloud properties, biogeochemical processes in the surface ocean, and atmospheric oxidative capacity (Cf Section 2.1).  Moreover, the expected drying of Central Chile may lead to a southward shifting of key agricultural activities, and population strengthening the pressures derived from the use of the territory in Southern Chile. Here again, it must be pointed out that large urban centers may offer effective means to mitigate climate change (e.g., Parrish and Zhu, 2009).Therefore an overarching focus of our proposal is to design effective measures to simultaneously control air pollution (photo-oxidants, particles, etc.) and to reduce climate change drivers (GHGs, aerosols, etc.). All research areas convened in this proposal are relevant to this end.

  • HD will address which are the needed changes to our legal bodies in order to provide a coherent and common policy framework for air quality and climate change (e.g., Bond, 2007; Arneth et al, 2009). Also, HD will examine plausible future socio-economic scenarios required for building adequate urban and industrial emission scenarios. HD contributions in terms of mapping formal and informal institutions to better design the required win-win options, and to avoid cultural and social implementation pitfalls will be fundamental.
    BGC, ECO and MO will provide understanding, models and observations to account for emission and removal of CATs and other tracers, the ways in which they interact with radiation and clouds, surrounding land and aquatic ecosystems, and very importantly, the ways in which urban areas per se perturb the atmospheric flow. CD and MO will contribute with climate change scenarios modulating these phenomena over time. Also, this will in turn allow exploring the manner in which the health of people is concomitantly affected by air pollution in a changing climate (Romero-Lankao et al, 2012), a matter of highest interest under HD.
  • BGC, ECO and CD will examine to what extent changes in coastal upwelling may alter primary production and thereby pelagic fisheries but also how subtle changes associated to land use changes may affect habitat-forming species, fish diseases, and in general food web dynamics.