The Role of HFCs in Mitigating 21st Century Climate Change

2016 ◽  
pp. 131-148
Keyword(s):  
2011 ◽  
Vol 2 (1) ◽  
pp. 133-159
Author(s):  
J. F. Tjiputra ◽  
O. H. Otterå

Abstract. Using a fully coupled global climate-carbon cycle model, we assess the potential role of volcanic eruptions on future projection of climate change and its associated carbon cycle feedback. The volcanic-like forcings are applied together with business-as-usual IPCC-A2 carbon emissions scenario. We show that very large volcanic eruptions similar to Tambora lead to short-term substantial global cooling. However, over a long period, smaller but more frequent eruptions, such as Pinatubo, would have a stronger impact on future climate change. In a scenario where the volcanic external forcings are prescribed with a five-year frequency, the induced cooling immediately lower the global temperature by more than one degree before return to the warming trend. Therefore, the climate change is approximately delayed by several decades and by the end of the 21st century, the warming is still below two degrees when compared to the present day period. The cooler climate reduces the terrestrial heterotrophic respiration in the northern high latitude and increases net primary production in the tropics, which contributes to more than 45% increase in accumulated carbon uptake over land. The increased solubility of CO2 gas in seawater associated with cooler SST is offset by reduced CO2 partial pressure gradient between ocean and atmosphere, which results in small changes in net ocean carbon uptake. Similarly, there is nearly no change in the seawater buffer capacity simulated between the different volcanic scenarios. Our study shows that even in the relatively extreme scenario where large volcanic eruptions occur every five-years period, the induced cooling only leads to a reduction of 46 ppmv atmospheric CO2 concentration as compared to the reference projection of 878 ppmv, at the end of the 21st century. With respect to sulphur injection geoengineering method, our study suggest that small scale but frequent mitigation is more efficient than the opposite. Moreover, the longer we delay, the more difficult it would be to counteract climate change.


2013 ◽  
Vol 13 (12) ◽  
pp. 6083-6089 ◽  
Author(s):  
Y. Xu ◽  
D. Zaelke ◽  
G. J. M. Velders ◽  
V. Ramanathan

Abstract. There is growing international interest in mitigating climate change during the early part of this century by reducing emissions of short-lived climate pollutants (SLCPs), in addition to reducing emissions of CO2. The SLCPs include methane (CH4), black carbon aerosols (BC), tropospheric ozone (O3) and hydrofluorocarbons (HFCs). Recent studies have estimated that by mitigating emissions of CH4, BC, and O3 using available technologies, about 0.5 to 0.6 °C warming can be avoided by mid-21st century. Here we show that avoiding production and use of high-GWP (global warming potential) HFCs by using technologically feasible low-GWP substitutes to meet the increasing global demand can avoid as much as another 0.5 °C warming by the end of the century. This combined mitigation of SLCPs would cut the cumulative warming since 2005 by 50% at 2050 and by 60% at 2100 from the CO2-only mitigation scenarios, significantly reducing the rate of warming and lowering the probability of exceeding the 2 °C warming threshold during this century.


Author(s):  
David Segal

Chapter 13 is the last chapter. It suggests how the 21st century may be described in terms of ‘ages’ analogous to the Bronze Age or Iron Age. Will the 21st century be described as the Silicon Age? Or perhaps be referred to as the Genomic Age? Or maybe the New Polymer Age? The role of climate change and international conflict on the pace of materials development are discussed.


2011 ◽  
Vol 2 (1) ◽  
pp. 53-67 ◽  
Author(s):  
J. F. Tjiputra ◽  
O. H. Otterå

Abstract. Using a fully coupled global climate-carbon cycle model, we assess the potential role of volcanic eruptions on future projection of climate change and its associated carbon cycle feedback. The volcanic-like forcings are applied together with a business-as-usual IPCC-A2 carbon emissions scenario. We show that very large volcanic eruptions similar to Tambora lead to short-term substantial global cooling. However, over a long period, smaller eruptions similar to Pinatubo in amplitude, but set to occur frequently, would have a stronger impact on future climate change. In a scenario where the volcanic external forcings are prescribed with a five-year frequency, the induced cooling immediately lower the global temperature by more than one degree before it returns to the warming trend. Therefore, the climate change is approximately delayed by several decades, and by the end of the 21st century, the warming is still below two degrees when compared to the present day period. Our climate-carbon feedback analysis shows that future volcanic eruptions induce positive feedbacks (i.e., more carbon sink) on both the terrestrial and oceanic carbon cycle. The feedback signal on the ocean is consistently smaller than the terrestrial counterpart and the feedback strength is proportionally related to the frequency of the volcanic eruption events. The cooler climate reduces the terrestrial heterotrophic respiration in the northern high latitude and increases net primary production in the tropics, which contributes to more than 45 % increase in accumulated carbon uptake over land. The increased solubility of CO2 gas in seawater associated with cooler SST is offset by a reduced CO2 partial pressure gradient between the ocean and the atmosphere, which results in small changes in net ocean carbon uptake. Similarly, there is nearly no change in the seawater buffer capacity simulated between the different volcanic scenarios. Our study shows that even in the relatively extreme scenario where large volcanic eruptions occur every five-years period, the induced cooling leads to a reduction of 46 ppmv atmospheric CO2 concentration as compared to the reference projection of 878 ppmv, at the end of the 21st century.


Author(s):  
Lisa Thalheimer ◽  
Ezekiel Simperingham ◽  
Eddie Wasswa Jjemba

Abstract Displacement due to weather and climate-related events (disaster displacement), including the adverse effects of climate change, is one of the greatest humanitarian challenges of the 21st century. Even though the forecasting of extreme events and early warning systems has improved globally, less attention has been given to translating anticipatory humanitarian action into the disaster displacement context with the aim to minimise forced displacement from extreme weather events through pre-allocated funds for the readiness, pre-positioning and activation costs. In this analysis, we assess the opportunities and challenges associated with utilising forecast-based financing (FbF) to expand anticipatory and early humanitarian action, based on the structured judgements of experts. These multi-disciplinary experts agree that FbF can reduce displacement risks and address the humanitarian impacts of disaster displacement early, or before a hazard materialises. We propose four action steps along the stages of disaster displacement to provide practical intervention points for researchers and practitioners. Finally, we discuss the implications of our findings and outline next steps. By integrating cross-disciplinary expert judgement, this paper provides a much-needed pathway to transform humanitarian action to be more anticipatory and adaptable to change, and help minimize disaster displacement in climate change vulnerable regions.


2019 ◽  
Vol 29 ◽  
pp. 49-57
Author(s):  
Sergey V.  Lebedev ◽  
Galina N.  Lebedeva

In the article the authors note that since the 1970s, with the rise of the Islamic movement and the Islamic revolution in Iran, philosophers and political scientists started to talk about religious renaissance in many regions of the world. In addition, the point at issue is the growing role of religion in society, including European countries that have long ago gone through the process of secularization. The reasons for this phenomenon, regardless of its name, are diverse, but understandable: secular ideologies of the last century failed to explain the existing social problems and give them a rational alternative.


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