Understanding climate change from a global analysis of city analogues

Combating climate change requires unified action across all sectors of society. However, this collective action is precluded by the ‘consensus gap’ between scientific knowledge and public opinion. Here, we test the extent to which the iconic cities around the world are likely to shift in response to climate change. By analyzing city pairs for 520 major cities of the world, we test if their climate in 2050 will resemble more closely to their own current climate conditions or to the current conditions of other cities in different bioclimatic regions. Even under an optimistic climate scenario (RCP 4.5), we found that 77% of future cities are very likely to experience a climate that is closer to that of another existing city than to its own current climate. In addition, 22% of cities will experience climate conditions that are not currently experienced by any existing major cities. As a general trend, we found that all the cities tend to shift towards the sub-tropics, with cities from the Northern hemisphere shifting to warmer conditions, on average ~1000 km south (velocity ~20 km.year-1), and cities from the tropics shifting to drier conditions. We notably predict that Madrid’s climate in 2050 will resemble Marrakech’s climate today, Stockholm will resemble Budapest, London to Barcelona, Moscow to Sofia, Seattle to San Francisco, Tokyo to Changsha. Our approach illustrates how complex climate data can be packaged to provide tangible information. The global assessment of city analogues can facilitate the understanding of climate change at a global level but also help land managers and city planners to visualize the climate futures of their respective cities, which can facilitate effective decision-making in response to on-going climate change.ISSN:1932-620

Correction: Understanding climate change from a global analysis of city analogues.

[This corrects the article DOI: 10.1371/journal.pone.0217592.]

Efficiency Assessment of an Evacuated U-Tube Solar Collector Using Silver Nanofluid

A water-based silver nanofluid (Ag/PW) was prepared from gelatin-stabilized silver nanoparticles (Ag NPs) of about 15 nm and further used as a working fluid in an evacuated U-tube solar collector (EUSC) to investigate the variation in the collector efficiency. An Ag/PW nanofluid having 0.035 wt\% was prepared and demonstrated a good promise of colloidal stability when dispersed in pure water. Collector efficiency measurements were carried out at outdoor conditions with four different mass flow rate values (0.063, 0.051, 0.033, and 0.02 kg/s). Results showed that Ag/PW have superior heat transfer properties than that of pure water as the base fluid. It was found that the efficiency of the collector was directly proportional to the mass flow rate of the working fluid until an optimum value was attained. Experimental results show that the highest collector efficiency was 72.2\% at 0.051 kg/s mass flow rate, which is 21.3\% higher than that of the pure water

Solar thermal collectors - Chapter 6

In this chapter, a summary review on a large variety of solar-based thermal energy conversion available technologies are presented. Specifically, the following investigated devices are suitably for the conversion of solar energy to provide heating for the hydrogen production. The chapter is subdivided into three sections. In the introductory section, the classification of the solar thermal collectors is reported. It also gives the definitions of different features characterizing solar thermal devices. Note that, the presented classification is based on these features. The second section gives an analysis of non-concentrator solar thermal collector. Both flat plate and evacuated tube technologies are investigated. Also, it provides information regarding optical and thermal performances of such devices and introduce how they can be physically modeled. In third section, the concentrator solar thermal collectors are introduced. Specifically, the compound parabolic, the parabolic through collectors, the linear Fresnel, and the parabolic dishes are here investigated