scholarly journals Methane and carbon dioxide emissions from 40 lakes along a north–south latitudinal transect in Alaska

2015 ◽  
Vol 12 (11) ◽  
pp. 3197-3223 ◽  
Author(s):  
A. Sepulveda-Jauregui ◽  
K. M. Walter Anthony ◽  
K. Martinez-Cruz ◽  
S. Greene ◽  
F. Thalasso

Abstract. Uncertainties in the magnitude and seasonality of various gas emission modes, particularly among different lake types, limit our ability to estimate methane (CH4) and carbon dioxide (CO2) emissions from northern lakes. Here we assessed the relationship between CH4 and CO2 emission modes in 40 lakes along a latitudinal transect in Alaska to lakes' physicochemical properties and geographic characteristics, including permafrost soil type surrounding lakes. Emission modes included direct ebullition, diffusion, storage flux, and a newly identified ice-bubble storage (IBS) flux. We found that all lakes were net sources of atmospheric CH4 and CO2, but the climate warming impact of lake CH4 emissions was 2 times higher than that of CO2. Ebullition and diffusion were the dominant modes of CH4 and CO2 emissions, respectively. IBS, ~10% of total annual CH4 emissions, is the release to the atmosphere of seasonally ice-trapped bubbles when lake ice confining bubbles begins to melt in spring. IBS, which has not been explicitly accounted for in regional studies, increased the estimate of springtime emissions from our study lakes by 320%. Geographically, CH4 emissions from stratified, mixotrophic interior Alaska thermokarst (thaw) lakes formed in icy, organic-rich yedoma permafrost soils were 6-fold higher than from non-yedoma lakes throughout the rest of Alaska. The relationship between CO2 emissions and geographic parameters was weak, suggesting high variability among sources and sinks that regulate CO2 emissions (e.g., catchment waters, pH equilibrium). Total CH4 emission was correlated with concentrations of soluble reactive phosphorus and total nitrogen in lake water, Secchi depth, and lake area, with yedoma lakes having higher nutrient concentrations, shallower Secchi depth, and smaller lake areas. Our findings suggest that permafrost type plays important roles in determining CH4 emissions from lakes by both supplying organic matter to methanogenesis directly from thawing permafrost and by enhancing nutrient availability to primary production, which can also fuel decomposition and methanogenesis.

2014 ◽  
Vol 11 (9) ◽  
pp. 13251-13307 ◽  
Author(s):  
A. Sepulveda-Jauregui ◽  
K. M. Walter Anthony ◽  
K. Martinez-Cruz ◽  
S. Greene ◽  
F. Thalasso

Abstract. Uncertainties in the magnitude and seasonality of various gas emission modes, particularly among different lake types, limit our ability to estimate methane (CH4) and carbon dioxide (CO2) emissions from northern lakes. Here we assessed the relationship between CH4 and CO2 emission modes in 40 lakes along a latitudinal transect in Alaska to physicochemical limnology and geographic characteristics, including permafrost soil type surrounding lakes. Emission modes included Direct Ebullition, Diffusion, Storage flux, and a newly identified Ice-Bubble Storage (IBS) flux. We found that all lakes were net sources of atmospheric CH4 and CO2, but the climate warming impact of lake CH4 emissions was two times higher than that of CO2. Ebullition and Diffusion were the dominant modes of CH4 and CO2 emissions respectively. IBS, ~ 10% of total annual CH4 emissions, is the release to the atmosphere of seasonally ice-trapped bubbles when lake ice confining bubbles begins to melt in spring. IBS, which has not been explicitly accounted for in regional studies, increased the estimate of springtime emissions from our study lakes by 320%. Geographically, CH4 emissions from stratified, dystrophic interior Alaska thermokarst (thaw) lakes formed in icy, organic-rich yedoma permafrost soils were 6-fold higher than from non-yedoma lakes throughout the rest of Alaska. Total CH4 emission was correlated with concentrations of phosphate and total nitrogen in lake water, Secchi depth and lake area, with yedoma lakes having higher nutrient concentrations, shallower Secchi depth, and smaller lake areas. Our findings suggest that permafrost type plays important roles in determining CH4 emissions from lakes by both supplying organic matter to methanogenesis directly from thawing permafrost and by enhancing nutrient availability to primary production, which can also fuel decomposition and methanogenesis.


2020 ◽  
Vol 66 (No. 4) ◽  
pp. 183-192 ◽  
Author(s):  
Abrham Tezera Gessesse ◽  
Ge He

This study examines the nexus of carbon dioxide (CO2) emissions, energy consumption (EC) and gross domestic products (GDP), using an Autoregressive Distributed Lag (ARDL) bounds test approach of co-integration and error-correction model (ECM) for the period 1971–2015. The aim of the research is to i) examine the relationship between CO2 and GDP as “cross-coupling, relative decoupling, or absolute decoupling,” and validate the existence of the Environmental Kuznets Curve (EKC) hypothesis; ii) detect causality between CO2 emissions, EC, and GDP, and scrutinize their impacts. The ARDL results confirm a long-run and short-run co-integration relationship between the variables. The relationship between CO2 emissions and GDP is “relatively decoupling,” and the EKC exists in China. Its CO2 emissions are more explained by EC and contribute twofold of GDP. In the long run, there was significant negative causality from CO2 emission and GDP to EC. This indicates Chinese economic development structure should be re-designed towards energy-saving and decarbonized economic structure. Moreover, the central and provincial governments of China should synchronize optimal energy utilization and green economic structure to mitigate environmental deterioration and climate change.


2021 ◽  
Vol 13 (7) ◽  
pp. 3660
Author(s):  
Rathna Hor ◽  
Phanna Ly ◽  
Agusta Samodra Putra ◽  
Riaru Ishizaki ◽  
Tofael Ahamed ◽  
...  

Traditional Cambodian food has higher nutrient balances and is environmentally sustainable compared to conventional diets. However, there is a lack of knowledge and evidence on nutrient intake and the environmental greenness of traditional food at different age distributions. The relationship between nutritional intake and environmental impact can be evaluated using carbon dioxide (CO2) emissions from agricultural production based on life cycle assessment (LCA). The objective of this study was to estimate the CO2 equivalent (eq) emissions from the traditional Cambodian diet using LCA, starting at each agricultural production phase. A one-year food consumption scenario with the traditional diet was established. Five breakfast (BF1–5) and seven lunch and dinner (LD1–7) food sets were consumed at the same rate and compared using LCA. The results showed that BF1 and LD2 had the lowest and highest emissions (0.3 Mt CO2 eq/yr and 1.2 Mt CO2 eq/yr, respectively). The food calories, minerals, and vitamins met the recommended dietary allowance. The country’s existing food production system generates CO2 emissions of 9.7 Mt CO2 eq/yr, with the proposed system reducing these by 28.9% to 6.9 Mt CO2 eq/yr. The change in each food item could decrease emissions depending on the type and quantity of the food set, especially meat and milk consumption.


2008 ◽  
Vol 8 (2) ◽  
pp. 7373-7389 ◽  
Author(s):  
A. Stohl

Abstract. Most atmospheric scientists agree that greenhouse gas emissions have already caused significant changes to the global climate system and that these changes will accelerate in the near future. At the same time, atmospheric scientists who – like other scientists – rely on international collaboration and information exchange travel a lot and, thereby, cause substantial emissions of carbon dioxide (CO2). In this paper, the CO2 emissions of the employees working at an atmospheric research institute (the Norwegian Institute for Air Research, NILU) caused by all types of business travel (conference visits, workshops, field campaigns, instrument maintainance, etc.) were calculated for the years 2005–2007. It is estimated that more than 90% of the emissions were caused by air travel, 3% by ground travel and 5% by hotel usage. The travel-related annual emissions were between 1.9 and 2.4 t CO2 per employee or between 3.9 and 5.5 t CO2 per scientist. For comparison, the total annual per capita CO2 emissions are 4.5 t worldwide, 1.2 t for India, 3.8 t for China, 5.9 t for Sweden and 19.1 t for Norway. The travel-related CO2 emissions of a NILU scientist, occurring in 24 days of a year on average, exceed the global average annual per capita emission. Norway's per-capita CO2 emissions are among the highest in the world, mostly because of the emissions from the oil industry. If the emissions per NILU scientist derived in this paper are taken as representative for the average Norwegian researcher, travel by Norwegian scientists would nevertheless account for a substantial 0.2% of Norway's total CO2 emissions. Since most of the travel-related emissions are due to air travel, water vapor emissions, ozone production and contrail formation further increase the relative importance of NILU's travel in terms of radiative forcing.


2021 ◽  
Author(s):  
Jean Baptiste Aboyitungiye ◽  
Suryanto Suryanto ◽  
Evi Gravitiani

Abstract The recent climatic phenomena observed in developing countries since the 2000s have raised concerns, fears, and debates within the international community and economists. Human activities are largely responsible for atmospheric warming through their emissions of CO2 and polluting substances with dramatic consequences and numerous losses of human life in some countries. Using panel data covering the 2000-2016 period, this study investigated the social vulnerability due to the CO2 emissions through an empirical study of CO2’s determinants in selected countries of sub-Sahara African and Southeast Asian countries. The STIRPAT model gave out the result that; explanatories causes of carbon dioxide emissions are different in the two regions: the agriculture-forestry and fishing value-added, and human development index have a strong explanatory power on CO2 emissions in the ASEAN countries, the per-capita domestic product has a positive and significant influence on carbon emissions in the SSA countries, ceteris paribus, but was statistically insignificant in the ASEAN countries. The growing population decreases carbon emissions in the SSA selected countries while is not statically significant in the ASEAN countries. There is therefore a kind of double penalty: those who suffer, and will suffer the most from the impacts of climate change due to CO2 emissions, are those who contribute the least to the problem. These results provide insight into future strategies for the mitigation of climatic hazards already present in some places and potential for others which will be felt on different scales across the regions. Some of the inevitable redistributive effects of those risks can be corrected by providing financial support to the poorest populations hardest hit by natural disasters.


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