http://www.omicsonline.org/2157-7617/2157-7617-4-143.php?aid=15726
Citation: Nogués S, Azcón-Bieto J (2013) Potential of Local Bio-Geoengineering to Mitigate Dangerous Temperature Increases in a Global Warming Scenario. J Earth Sci Clim Change 4:143. Received April 10, 2013; Accepted June 28, 2013; Published July 03, 2013 Extract (no abstract) So, is it possible to avoid the effects of global warming if CO2 emissions continue as they are? This is an important question since most of the negative effects of climate change, not only those affecting plants and ecosystems, are related to an increase in global temperatures. We propose here that the extent of global warming can be controlled directly through local geo-engineering approaches, which could be achieved at a reasonable cost. An example of this relatively low cost approach is connected with the management of solar radiation (i.e. by increasing the global albedo). Evidence for this can be found in the south-eastern part of Spain where a significant surface air temperature trend of -0.3° C per decade has been observed due to a dramatic expansion of greenhouse horticulture (reaching a continuous area of 26,000 ha in 2007), the most extensive greenhouse area in the world Figure 1 [25]. Increasing urban albedo can reduce air temperatures and can result in less absorption of incoming solar radiation by the surface-troposphere system [26]. Since pavements and roofs typically constitute over 60% of urban surfaces, the albedo of both could be increased through the use of reflective materials by ca. 0.25 W m-2 and 0.15 W m-2, respectively. This would result in a net albedo increase for urban areas of ca. 0.1 W m-2, thereby offsetting around 44 Gt of CO2 emissions [26]. This 44 Gt CO2 offset is over 1 year of the 2025 projected world-wide emission of 37 Gt of CO2 per year [26]. Moreover, Ridgwell et al. [27] have proposed a new approach in the mitigation of surface warming, where crop varieties which have specific leaf glossiness and/or canopy morphological traits could be chosen specifically in order to maximize solar reflectivity [27]. Using an ocean–atmosphere–vegetation model, Singarayer et al. [21] have investigated to what extent the regional effectiveness of crop albedo bio-geoengineering might have on a progressively warming climate [7]. They found that the averted warming due to increasing the albedo of the crop canopy by 0.04 is regionally and seasonally specific, with the greatest cooling of ca. 1°C for Europe in summer whereas in the low latitude monsoonal SE Asian regions of high density cropland, the greatest cooling is experienced in winter. However, despite the small global impact, regionally focused schemes such as crop albedo bio-geoengineering have provided certain benefits. Furthermore, according to models, solar-radiation geoengineering in high-CO2 environments generally produces an increase in crop yields, largely because temperature stresses are diminished while the benefits of CO2 fertilization are retained [28]. However, Irvine et al. [6] have looked at the regional and global impacts of different bio-geoengineering approaches and have found that the cooling effect of surface albedo modification is seasonal and mostly confined to the areas of application. In terms of urban and cropland geoengineering, the global effects are minor, but since they are located within areas of human activity, they may provide some regional benefits. In summary, the selection of crop varieties with higher reflectivity, the use of reflective pavements, painting buildings and roofs with light colours, and other similar bio-geoengineering approaches at a local level will lead to an increase in albedo and thus decrease global temperatures. In addition to efforts currently underway to reduce CO2 emissions, this body of evidence suggests that the use of local biogeoengineering can increase local surface albedo and, consequently, decreasing surface temperature, that in turn could increase growth rates of plants. However, it must be stated that we are not advocating the use of local bio-geoengineering as an alternative to reducing CO2, but rather that these bio-geoengineering solutions could be implemented in parallel with other programs for the reduction of CO2 emissions. Furthermore, these could easily be implemented in developing countries, and at the same time help to bring new opportunities to their economies. Each country should therefore find the local ‘non-costly’ bio-geoengineering approaches that best suit their situation and adapted to their capabilities (such as changing crop albedo, urban surfaces, and so on). -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out.
