News

Unravelling the sources of carbon emissions at the onset of Oceanic Anoxic Event (OAE) 1a

Abstract.

"The early Aptian Oceanic Anoxic Event (OAE) 1a represents a major perturbation of the Earth's climate system and in particular the carbon cycle, as evidenced by widespread preservation of organic matter in marine settings and a characteristic negative carbon isotopic excursion (CIE) at its onset, followed by a broad positive CIE. The contemporaneous emplacement of a large igneous province (LIP) is invoked as a trigger for OAE 1a (and OAEs in general), but this link and the ultimate source of the carbon perturbation at the onset of OAEs is still debated. [...]"

Source: 
Authors: Markus Adloff et al.
DOI: 10.1016/j.epsl.2019.115947

Read the full article here.


Meeting climate targets by direct CO2 injections: what price would the ocean have to pay?

Abstract.

"We investigate the climate mitigation potential and collateral effects of direct injections of captured CO2 into the deep ocean as a possible means to close the gap between an intermediate CO2 emissions scenario and a specific temperature target, such as the 1.5 C target aimed for by the Paris Agreement. For that purpose, a suite of approaches for controlling the amount of direct CO2 injections at 3000 m water depth are implemented in an Earth system model of intermediate complexity. [...]"

Source: Earth System Dynamics
Authors: Fabian Reith et al.
DOI: 10.5194/esd-10-711-2019

Read the full article here.


Marine nitrogen fixers mediate a low latitude pathway for atmospheric CO2 drawdown

Abstract.

"Roughly a third (~30 ppm) of the carbon dioxide (CO2) that entered the ocean during ice ages is attributed to biological mechanisms. A leading hypothesis for the biological drawdown of CO2 is iron (Fe) fertilisation of the high latitudes, but modelling efforts attribute at most 10 ppm to this mechanism, leaving ~20 ppm unexplained [...]"

Source: Nature Communications 
Authors: Pearse J. Buchanan et al.
DOI: 10.1038/s41467-019-12549-z

Read the full article here.


Ocean phosphorus inventory: large uncertainties in future projections on millennial timescales and their consequences for ocean deoxygenation

Abstract.

"Previous studies have suggested that enhanced weathering and benthic phosphorus (P) fluxes, triggered by climate warming, can increase the oceanic P inventory on millennial timescales, promoting ocean productivity and deoxygenation. In this study, we assessed the major uncertainties in projected P inventories and their imprint on ocean deoxygenation using an Earth system model of intermediate complexity for the same business-as-usual carbon dioxide (CO2) emission scenario until the year 2300 and subsequent linear decline to zero emissions until the year 3000. [...]"

Source: Earth System Dynamics
Authors: Tronje P. Kemena et al.
DOI: 10.5194/esd-10-539-2019

Read the full article here.


As oceans warm, microbes could pump more CO2 back into air, study warns

"The world's oceans soak up about a quarter of the carbon dioxide that humans pump into the air each year -- a powerful brake on the greenhouse effect. In addition to purely physical and chemical processes, a large part of this is taken up by photosynthetic plankton as they incorporate carbon into their bodies. When plankton die, they sink, taking the carbon with them. Some part of this organic rain will end up locked into the deep ocean, insulated from the atmosphere for centuries or more. [...]"

Source: EurekAlert!

Read the full article here.


Enhanced North Pacific deep-ocean stratification by stronger intermediate water formation during Heinrich Stadial 1

Abstract.

"The deglacial history of CO2 release from the deep North Pacific remains unresolved. This is due to conflicting indications about subarctic Pacific ventilation changes based on various marine proxies, especially for Heinrich Stadial 1 (HS-1) when a rapid atmospheric CO2 rise occurs. Here, we use a complex Earth System Model to investigate the deglacial North Pacific overturning and its control on ocean stratification. [...]"

Source: Nature Communications
Authors: X. Gong et al.
DOI: 10.1038/s41467-019-08606-2

Read the full article here.


Asymmetric dynamical ocean responses in warming icehouse and cooling greenhouse climates

Abstract.

"Warm periods in Earth's history tend to cool more slowly than cool periods warm. Here we explore initial differences in how the global ocean takes up and gives up heat and carbon in forced rapid warming and cooling climate scenarios. We force an intermediate-complexity earth system model using two atmospheric CO2 scenarios. A ramp-up (1% per year increase in atmospheric CO2 for 150 years) starts from an average global CO2 concentration of 285 ppm to represent warming of an icehouse climate. [...]"

Source: Environmental Research Letters
Authors: Karin F. Kvale et al.
DOI: 10.1088/1748-9326/aaedc3

Read the full article here.


Effects of Higher CO2 and Temperature on Exopolymer Particle Content and Physical Properties of Marine Aggregates

Abstract.

"We investigated how future ocean conditions, and specifically the interaction between temperature and CO2, might affect marine aggregate formation and physical properties. Initially, mesocosms filled with coastal seawater were subjected to three different treatments of CO2 concentration and temperature: (1) 750 ppm CO2, 16°C, (2) 750 ppm CO2, 20°C, and (3) 390 ppm CO2, 16°C. Diatom-dominated phytoplankton blooms were induced in the mesocosms by addition of nutrients. [...]"

Source: Frontiers in Marine Science
Authors: Carolina Cisternas-Novoa et al.
DOI: 10.3389/fmars.2018.00500

Read the full article here.


Major intensification of Atlantic overturning circulation at the onset of Paleogene greenhouse warmth

Abstract.

"During the Late Cretaceous and early Cenozoic the Earth experienced prolonged climatic cooling most likely caused by decreasing volcanic activity and atmospheric CO2 levels. However, the causes and mechanisms of subsequent major global warming culminating in the late Paleocene to Eocene greenhouse climate remain enigmatic. We present deep and intermediate water Nd-isotope records from the North and South Atlantic to decipher the control of the opening Atlantic Ocean on ocean circulation and its linkages to the evolution of global climate. [...]"

Source: Nature Communications
Authors: S. J. Batenburg et al.
DOI: 10.1038/s41467-018-07457-7

Read the full article here.


Glacial expansion of oxygen-depleted seawater in the eastern tropical Pacific

Abstract.

"Increased storage of carbon in the oceans has been proposed as a mechanism to explain lower concentrations of atmospheric carbon dioxide during ice ages; however, unequivocal signatures of this storage have not been found. In seawater, the dissolved gases oxygen and carbon dioxide are linked via the production and decay of organic material, with reconstructions of low oxygen concentrations in the past indicating an increase in biologically mediated carbon storage. [...]"

Source: Nature
Authors: Babette A. A. Hoogakker et al.
DOI: 10.1038/s41586-018-0589-x

Read the full article here.


Showing 1 - 10 of 16 results.
Items per Page 10
of 2