Energy, the Carbon Cycle, and Enduring Greenhouse Gas Management

2006 ◽  
Author(s):  
Duane Pendergast
Keyword(s):  
Carbon Cycle ◽  
Greenhouse Gas

scholarly journals The Archean atmosphere

2020 ◽  
Vol 6 (9) ◽  
pp. eaax1420 ◽  
Author(s):  
David C. Catling ◽  
Kevin J. Zahnle
Keyword(s):  
Carbon Cycle ◽  
Greenhouse Gas ◽  
Solid Earth ◽  
Atmospheric Composition ◽  
Detailed Understanding ◽  
Average Surface ◽  
Substantial Loss ◽  
Mass Fractionation ◽  
The Earth ◽  
Surface Temperatures

The atmosphere of the Archean eon—one-third of Earth’s history—is important for understanding the evolution of our planet and Earth-like exoplanets. New geological proxies combined with models constrain atmospheric composition. They imply surface O2 levels <10−6 times present, N2 levels that were similar to today or possibly a few times lower, and CO2 and CH4 levels ranging ~10 to 2500 and 102 to 104 times modern amounts, respectively. The greenhouse gas concentrations were sufficient to offset a fainter Sun. Climate moderation by the carbon cycle suggests average surface temperatures between 0° and 40°C, consistent with occasional glaciations. Isotopic mass fractionation of atmospheric xenon through the Archean until atmospheric oxygenation is best explained by drag of xenon ions by hydrogen escaping rapidly into space. These data imply that substantial loss of hydrogen oxidized the Earth. Despite these advances, detailed understanding of the coevolving solid Earth, biosphere, and atmosphere remains elusive, however.

scholarly journals Defining Genomic and Predicted Metabolic Features of the Acetobacterium Genus

mSystems ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Daniel E. Ross ◽  
Christopher W. Marshall ◽  
Djuna Gulliver ◽  
Harold D. May ◽  
R. Sean Norman
Keyword(s):  
Carbon Cycle ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Anaerobic Bacteria ◽  
Global Carbon Cycle ◽  
Acetyl Coa ◽  
Gas Emissions ◽  
Autotrophic Metabolism ◽  
Fuels And Chemicals ◽  
Global Carbon

Acetogens are anaerobic bacteria capable of fixing CO2 or CO to produce acetyl-CoA and ultimately acetate using the Wood-Ljungdahl pathway (WLP). This autotrophic metabolism plays a major role in the global carbon cycle and, if harnessed, can help reduce greenhouse gas emissions. Overall, the data presented here provide a framework for examining the ecology and evolution of the Acetobacterium genus and highlight the potential of these species as a source for production of fuels and chemicals from CO2 feedstocks.

scholarly journals Carboxylases in Natural and Synthetic Microbial Pathways

2011 ◽  
Vol 77 (24) ◽  
pp. 8466-8477 ◽  
Author(s):  
Tobias J. Erb
Keyword(s):  
Carbon Dioxide ◽  
Synthetic Biology ◽  
Carbon Cycle ◽  
Greenhouse Gas ◽  
Inorganic Carbon ◽  
Carbon Assimilation ◽  
Value Added ◽  
Global Carbon Cycle ◽  
Global Carbon ◽  
Novel Antibiotics

ABSTRACTCarboxylases are among the most important enzymes in the biosphere, because they catalyze a key reaction in the global carbon cycle: the fixation of inorganic carbon (CO2). This minireview discusses the physiological roles of carboxylases in different microbial pathways that range from autotrophy, carbon assimilation, and anaplerosis to biosynthetic and redox-balancing functions. In addition, the current and possible future uses of carboxylation reactions in synthetic biology are discussed. Such uses include the possible transformation of the greenhouse gas carbon dioxide into value-added compounds and the production of novel antibiotics.

scholarly journals Saving the planet with appropriate biotechnology: 1. Diagnosing the problems

2021 ◽  
Vol 6 (1) ◽  
pp. 1-30
Author(s):  
David Moore ◽  
◽  
Matthias Heilweck ◽  
Peter Petros ◽  
◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Fossil Fuels ◽  
Industrial Revolution ◽  
Global Climate ◽  
Plain Language ◽  
Gas Emissions ◽  
Short Account ◽  
Dangerous Anthropogenic Interference

We give a plain language guide to the Earth’s carbon cycle by briefly summarising the observations and origins of increased levels of greenhouse gases, mainly CO2 but including CH4 and N2O, in our atmosphere. The only tenable explanation for our atmosphere’s present state is that it is the consequence of mankind’s excessive use of fossil fuels since the Industrial Revolution onwards. We deal with the arguments that deny the truth of this, then illustrate the Earth’s global carbon cycle, which was almost exactly in equilibrium for several thousand years while humans were evolving, before industrial humans intervened. We describe how the excess greenhouse gas emissions are projected to change the global climate over this century and beyond and discuss ‘dangerous anthropogenic interference’ (DAI), ‘reasons for concern’ (RFCs) and climate tipping points. Finally, we give a short account of the various improved management, engineering and natural climate solutions advocated to increase carbon storage and/or avoid greenhouse gas emissions across global forests, wetlands, grasslands, agricultural lands, and industry. This review concludes with our basic message, which is that cultivation of aquatic calcifiers (coccolithophore algae, corals, crustacea and molluscs) offers the only effective and permanent carbon sequestration strategy.

Carbon Cycle Uncertainty Increases Climate Change Risks and Mitigation Challenges

2012 ◽  
Vol 25 (21) ◽  
pp. 7660-7668 ◽  
Author(s):  
Paul A. T. Higgins ◽  
John Harte
Keyword(s):  
Climate Change ◽  
Carbon Cycle ◽  
Greenhouse Gas ◽  
Atmospheric Carbon Dioxide ◽  
Climate Changes ◽  
Ice Age ◽  
Terrestrial Carbon ◽  
Plant Migration ◽  
Safe Level ◽  
Climate Change Risks

Projections of greenhouse gas concentrations over the twenty-first century generally rely on two optimistic, but questionable, assumptions about the carbon cycle: 1) that elevated atmospheric CO2 concentrations will enhance terrestrial carbon storage and 2) that plant migration will be fast relative to climate changes. This paper demonstrates that carbon cycle uncertainty is considerably larger than currently recognized and that plausible carbon cycle responses could strongly amplify climate warming. This has important implications for societal decisions that relate to climate change risk management because it implies that a given level of human emissions could result in much larger climate changes than we now realize or that stabilizing atmospheric greenhouse gas concentrations at a “safe” level could require lower human emissions than currently understood. These results also suggest that terrestrial carbon cycle responses could be sufficiently strong to account for the changes in atmospheric carbon dioxide that occurred during transitions between ice age and interglacial periods.

Soil and Climate Change

Earth Matters ◽  
2016 ◽  
Author(s):  
Richard Bardgett
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Carbon Cycle ◽  
Greenhouse Gases ◽  
Greenhouse Gas ◽  
Fossil Fuels ◽  
Global Climate ◽  
Intensive Farming ◽  
Weather Events ◽  
Carbon Store

The world’s climate is changing. Not only is it getting warmer, but also there are more extreme weather events, such as droughts, storms, and catastrophic floods. Humans are undoubtedly the cause of this change in climate, through the burning of fossil fuels, intensive farming, deforestation, and many other aspects of our industrious lives that increase the emission of greenhouse gases—carbon dioxide, methane, and nitrous oxide—to the atmosphere. In fact, over the past fifty years or so there has been an unprecedented increase in the release of greenhouse gases to the atmosphere, and, unless measures are put in place to cap emissions, this trend is likely to continue. So what have soils got to do with climate change? Put simply, soils play a pivotal role because they act as both a source and sink for greenhouse gases, and any disruption of this balance will affect the concentration of these gases in the atmosphere and hence the global climate, potentially making the situation either better or worse. Perhaps the most powerful illustration of this concerns the carbon cycle. Soil is the Earth’s third largest carbon store, next to the oceans and deep deposits of fossil fuels, and together with vegetation it contains at least three times more carbon than the atmosphere. Many worry that climate change will destabilize these carbon stores by stimulating the soil organisms that break down soil organic matter, releasing vast quantities of carbon dioxide to the atmosphere. This could shift soils from being sinks to sources of this greenhouse gas, thereby accelerating climate change. Scientists call this carbon-cycle feedback, and we will revisit it later. Let’s begin with the main actors of climate change, the greenhouse gases. The most abundant and well-known greenhouse gas is carbon dioxide. This gas is taken up from the atmosphere by plants through the process of photosynthesis, which occurs in the presence of light. Plants retain most of the carbon they take up and use it to grow and sustain their metabolism, but they also release a portion back to the atmosphere as carbon dioxide through respiration from both their shoots and roots.

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