scholarly journals Site-specific global warming potentials of biogenic CO 2 for bioenergy: contributions from carbon fluxes and albedo dynamics

2012 ◽  
Vol 7 (4) ◽  
pp. 045902 ◽  
Author(s):  
Francesco Cherubini ◽  
Ryan M Bright ◽  
Anders H Strømman
2016 ◽  
Author(s):  
Anna Totterdill ◽  
Tamás Kovács ◽  
Wuhu Feng ◽  
Sandip Dhomse ◽  
Christopher J. Smith ◽  
...  

Abstract. Fluorinated compounds such as NF3 and C2F5Cl (CFC-115) are characterised by very large global warming potentials (GWPs) which result from extremely long atmospheric lifetimes and strong infrared absorptions in the atmospheric window. In this study we have experimentally determined the infrared absorption cross-sections of NF3 and CFC-115, calculated the radiative forcing and efficiency using two radiative transfer models and identified the effect of clouds and stratospheric adjustment. The infrared cross sections are in good agreement with previous measurements, whereas the resulting radiative forcings and efficiencies are, on average, around 10 % larger. A whole atmosphere chemistry-climate model was used to determine the atmospheric lifetimes of NF3 and CFC-115 to be (616 ± 34) years and (492 ± 22) years, respectively. The GWPs for NF3 are estimated to be 14 600, 19 400 and 21 400 over 20, 100 and 500 years, respectively. Similarly, the GWPs for CFC-115 are 6120, 8060 and 8630 over 20, 100 and 500 years, respectively.


2008 ◽  
Vol 10 (6) ◽  
pp. 808-820 ◽  
Author(s):  
Vassileios C. Papadimitriou ◽  
Ranajit K. Talukdar ◽  
R. W. Portmann ◽  
A. R. Ravishankara ◽  
James B. Burkholder

Author(s):  
Ahmad Sleiti ◽  
Wahib Al-Ammari ◽  
Mohammed Al-Khawaja ◽  
Maxim Glushenkov ◽  
Alexander Kronberg

Around 17% of the globally generated energy is consumed for residential, commercial, and transportation refrigeration. The current cooling technologies utilize refrigerants with high Ozone Depletion and Global Warming Potentials. Furthermore, the current technologies are expensive alongside with toxicity and flammability hazards. On the other side, energy produced by combustion of fossil fuels results in substantial amounts of waste heat. Therefore, it is necessary to develop new refrigeration technologies that utilize waste heat as a source of energy with ecofriendly refrigerants with zero ozone depletion potential and zero global warming potential. In addition, this thermal mechanical refrigeration (TMR) technology improves the energy efficiency of the source of waste heat system and minimizes the emissions of the carbon dioxide (CO2). In this study, a novel thermo-mechanical refrigeration system is proposed. It operates with low-grade energy sources (such as waste heat) at temperature range of 60 oC to 100 oC. Furthermore, it has the advantage of working with low-frequency driver-compressor unit, which eliminates noise and increases its lifetime. Moreover, the TMR system is adaptable to commercial, transportation, and residential refrigeration applications.


2021 ◽  
Author(s):  
Tom M. L. Wigley

Abstract This paper provides an assessment of Article 4.1 of the Paris Agreement on climate; the main goal of which is to provide guidance on how “to achieve the long-term temperature goal set out in Article 2”. Paraphrasing, Article 4.1 says that, to achieve this end, we should decrease greenhouse gas (GHG) emissions so that net anthropogenic GHG emissions fall to zero in the second half of this century. To aggregate net GHG emissions, 100-year Global Warming Potentials (GWP-100) are commonly used to convert non-CO2 emissions to equivalent CO2 emissions. As a test case using methane, temperature projections using GWP-100 scaling are shown to be seriously in error. This throws doubt on the use of GWP-100 scaling to estimate net GHG emissions. An alternative method to determine the net-zero point for GHG emissions based on radiative forcing is derived. This shows that the net-zero point needs to be reached as early as 2036, much sooner than in the Article 4.1 window. Other scientific flaws in Article 4.1 that further undermine its purpose to guide efforts to achieve the Article 2 temperature targets are discussed.


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