scholarly journals Gas emissions at the continental margin west of Svalbard: mapping, sampling, and quantification

2014 ◽  
Vol 11 (21) ◽  
pp. 6029-6046 ◽  
Author(s):  
H. Sahling ◽  
M. Römer ◽  
T. Pape ◽  
B. Bergès ◽  
C. dos Santos Fereirra ◽  
...  
Keyword(s):  
Global Warming ◽  
Continental Margin ◽  
Water Depth ◽  
Bottom Water ◽  
Hydrate Formation ◽  
Late Summer ◽  
Remotely Operated Vehicle ◽  
Gas Emissions ◽  
Single Beam ◽  
The Future

Abstract. We mapped, sampled, and quantified gas emissions at the continental margin west of Svalbard during R/V Heincke cruise He-387 in late summer 2012. Hydroacoustic mapping revealed that gas emissions were not limited to a zone just above 396 m water depth. Flares from this depth have gained significant attention in the scientific community in recent years because they may be caused by bottom-water warming-induced hydrate dissolution in the course of global warming and/or by recurring seasonal hydrate formation and decay. We found that gas emissions occurred widespread between about 80 and 415 m water depth, which indicates that hydrate dissolution might only be one of several triggers for active hydrocarbon seepage in that area. Gas emissions were remarkably intensive at the main ridge of the Forlandet moraine complex in 80 to 90 m water depths, and may be related to thawing permafrost. Focused seafloor investigations were performed with the remotely operated vehicle (ROV) "Cherokee". Geochemical analyses of gas bubbles sampled at about 240 m water depth as well as at the 396 m gas emission sites revealed that the vent gas is primarily composed of methane (> 99.70%) of microbial origin (average δ13C = −55.7‰ V-PDB). Estimates of the regional gas bubble flux from the seafloor to the water column in the area of possible hydrate decomposition were achieved by combining flare mapping using multibeam and single-beam echosounder data, bubble stream mapping using a ROV-mounted horizontally looking sonar, and quantification of individual bubble streams using ROV imagery and bubble counting. We estimated that about 53 × 106 mol methane were annually emitted at the two areas and allow for a large range of uncertainty due to our method (9 to 118 × 106 mol yr−1). First, these amounts show that gas emissions at the continental margin west of Svalbard were on the same order of magnitude as bubble emissions at other geological settings; second, they may be used to calibrate models predicting hydrate dissolution at present and in the future; and third, they may serve as a baseline (year 2012) estimate of the bubble flux that will potentially increase in the future due to ever-increasing global-warming-induced bottom water warming and hydrate dissociation.

scholarly journals Gas emissions at the continental margin west off Svalbard: mapping, sampling, and quantification

2014 ◽  
Vol 11 (5) ◽  
pp. 7189-7234 ◽  
Author(s):  
H. Sahling ◽  
M. Römer ◽  
T. Pape ◽  
B. Bergès ◽  
C. dos Santos Fereirra ◽  
...  
Keyword(s):  
Global Warming ◽  
Continental Margin ◽  
Bottom Water ◽  
Hydrate Formation ◽  
Late Summer ◽  
Remotely Operated Vehicle ◽  
Gas Emissions ◽  
Single Beam ◽  
Hydrate Decomposition ◽  
Order Of Magnitude

Abstract. We mapped, sampled, and quantified gas emissions at the continental margin west of Svalbard during R/V Heincke cruise He-387 in late summer 2012. Hydroacoustic mapping revealed that gas emissions were not limited to a zone just above 396 m below sea level (m b.s.l.). Flares from this depth gained significant attention in the scientific community in recent years because they may be caused by bottom water-warming induced hydrate dissolution in the course of global warming and/or by recurring seasonal hydrate formation and decay. We found that gas emissions occurred widespread between about 80 and 415 m b.s.l. which indicates that hydrate dissolution might only be one of several triggers for active hydrocarbon seepage in that area. Gas emissions were remarkably intensive at the main ridge of the forlandet moraine complex in 80 to 90 m water depths, and may be related to thawing permafrost. Focused seafloor investigations were performed with the remotely operated vehicle (ROV) "Cherokee". Geochemical analyses of gas bubbles sampled at about 240 m b.s.l. as well as at the 396 m gas emission sites revealed that the vent gas is primarily composed of methane (> 99.70%) of microbial origin (average δ13C = −55.7‰ V-PDB). Estimates of the regional gas bubble flux from the seafloor to the water column in the area of possible hydrate decomposition were achieved by combining flare mapping using multibeam and single beam echosounder data, bubble stream mapping using a ROV-mounted horizontally-looking sonar, and quantification of individual bubble streams using ROV imagery and bubble counting. We estimated that about 53 × 106 mol methane were annually emitted at the two areas and allow a large range of uncertainty due to our method (9 to 118 × 106 mol yr−1). These amounts, first, show that gas emissions at the continental margin west of Svalbard were in the same order of magnitude as bubble emissions at other geological settings, and second, may be used to calibrate models predicting hydrate dissolution at present and in the future, third, may serve as baseline (year 2012) estimate of the bubble flux that will potentially increase in future due to ever-increasing global-warming induced bottom water-warming and hydrate dissolution.

scholarly journals Shortened Duration of Global Warming Slowdowns with Elevated Greenhouse Gas Emissions

2021 ◽  
Vol 35 (2) ◽  
pp. 225-237
Author(s):  
Feng Gao ◽  
Tongwen Wu ◽  
Jie Zhang ◽  
Aixue Hu ◽  
Gerald A. Meehl
Keyword(s):  
Global Warming ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Gas Emissions

Future changes in Beijing haze events under different shared socioeconomic pathways

2021 ◽  
Author(s):  
Liang Guo ◽  
Laura Wilcox ◽  
Massimo Bollasina ◽  
Steven Turnock ◽  
Marianne Lund ◽  
...  
Keyword(s):  
Air Pollution ◽  
Global Warming ◽  
Greenhouse Gases ◽  
Weather Patterns ◽  
Greenhouse Gases Emissions ◽  
Wide Range ◽  
The Future ◽  
Aerosol Emissions

<p>The occurrence of severe haze events remains a serious problem in Beijing. Previous studies suggested that the frequency of weather patterns conducive to haze may increase with global warming. The new Shared Socioeconomic Pathways (SSPs) cover a wide range of uncertainties in aerosol and greenhouse gases emissions. Global and Chinese aerosol emissions are projected to decrease in most SSPs, while increases in greenhouse gases and global warming will continue for the rest of the century. The future, therefore, remains unclear.</p><p>We quantified the air pollution over Beijing and associated weather patterns using multiple indices calculated from the SSPs</p><p>We show that the occurrence of weather patterns conducive to the formation of haze significantly increases by the end of the century due to increases in greenhouse gases. Aerosol reductions also cause an increase in their occurrence, but reduce the severity of haze, and overall reducing aerosol emissions will be beneficial.</p>

President Greenwald's Man

2022 ◽  
Vol 3 (1) ◽  
pp. 17-29
Author(s):  
Cory Swanson ◽  
Keyword(s):  
Global Warming ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Short Story ◽  
Presidential Campaign ◽  
Single Issue ◽  
Gas Emissions

To what degree do serious issues require serious consequences for politicians who fail to address them? Should politicians who fail to keep campaign promises have greater consequences than not being reelected? In this work of philosophical short story fiction, Brian Greenwald is running a unique presidential campaign. Not only is he a single-issue candidate for stopping global warming, but an ominous figure follows him everywhere with the promise to kill him at the end of his term if he fails to move the needle. The electorate knows this, and elects Greenwald President in a landslide. Everything he does in office is focused on the single goal of lower greenhouse gas emissions. At the end of his first term emissions have gone flat, but not down. By the end of his second term, even after exceptional efforts, global greenhouse gas emissions have failed to significantly fall. Good to his word, the ominous figure kills him for failing to deliver.

Make the change

2021 ◽  
Vol 23 (3) ◽  
pp. S14-S15
Author(s):  
Claire Hewson
Keyword(s):  
Global Warming ◽  
Positive Impact ◽  
Natural World ◽  
The Future

Against the background of the pandemic and global warming, the theme of The Big Draw 2021, an art festival which takes place this month, is ‘Make the change’. The focus is to explore the ways we look after each other and the natural world to make a positive impact on the future.

Global warming and forest fires in Canada

1993 ◽  
Vol 69 (3) ◽  
pp. 290-293 ◽  
Author(s):  
Brian J. Stocks
Keyword(s):  
Global Warming ◽  
Forest Fire ◽  
Forest Fires ◽  
Fire Management ◽  
Warming Trend ◽  
Research Activities ◽  
Forest Fire Management ◽  
The Future ◽  
Innovative Thinking ◽  
The Impact

The looming possibility of global warming raises legitimate concerns for the future of the forest resource in Canada. While evidence of a global warming trend is not conclusive at this time, governments would be wise to anticipate, and begin planning for, such an eventuality. The forest fire business is likely to be affected both early and dramatically by any trend toward warmer and drier conditions in Canada, and fire managers should be aware that the future will likely require new and innovative thinking in forest fire management. This paper summarizes research activities currently underway to assess the impact of global warming on forest fires, and speculates on future fire management problems and strategies.

scholarly journals Impacts of 1.5 and 2.0 °C Global Warming on Water Balance Components over Senegal in West Africa

Atmosphere ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 712
Author(s):  
Mamadou Lamine Mbaye ◽  
Mouhamadou Bamba Sylla ◽  
Moustapha Tall
Keyword(s):  
Global Warming ◽  
West Africa ◽  
Water Deficit ◽  
Climate Model ◽  
Regional Climate ◽  
Climate Change Impacts ◽  
Water Balance Components ◽  
Global Mean Temperature ◽  
The Future ◽  
Annual Water

This study assesses the changes in precipitation (P) and in evapotranspiration (ET) under 1.5 °C and 2.0 °C global warming levels (GWLs) over Senegal in West Africa. A set of twenty Regional Climate Model (RCM) simulations within the Coordinated Regional Downscaling Experiment (CORDEX) following the Representative Concentration Pathways (RCP) 4.5 emission scenario is used. Annual and seasonal changes are computed between climate simulations under 1.5 °C and 2.0 °C warming, with respect to 0.5 °C warming, compared to pre-industrial levels. The results show that annual precipitation is likely to decrease under both magnitudes of warming; this decrease is also found during the main rainy season (July, August, September) only and is more pronounced under 2 °C warming. All reference evapotranspiration calculations, from Penman, Hamon, and Hargreaves formulations, show an increase in the future under the two GWLs, except annual Penman evapotranspiration under the 1.5 °C warming scenario. Furthermore, seasonal and annual water balances (P-ET) generally exhibit a water deficit. This water deficit (up to 180 mm) is more substantial with Penman and Hamon under 2 °C. In addition, analyses of changes in extreme precipitation reveal an increase in dry spells and a decrease in the number of wet days. However, Senegal may face a slight increase in very wet days (95th percentile), extremely wet days (99th), and rainfall intensity in the coming decades. Therefore, in the future, Senegal may experience a decline in precipitation, an increase of evapotranspiration, and a slight increase in heavy rainfall. Such changes could have serious consequences (e.g., drought, flood, etc.) for socioeconomic activities. Thus, strong governmental politics are needed to restrict the global mean temperature to avoid irreversible negative climate change impacts over the country. The findings of this study have contributed to a better understanding of local patterns of the Senegal hydroclimate under the two considered global warming scenarios.

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