Carbon storage and continental land surface change since the last glacial maximum

Abstract. When the climate is reconstructed from paleoevidence, it shows that the Last Glacial Maximum (LGM, ca. 21 000 yr ago) is cold and dry compared to the present-day. Reconstruction also shows that compared to today, the vegetation of the LGM is less active and the distribution of vegetation was drastically different, due to cold temperature, dryness, and a lower level of atmospheric CO2 concentration (185 ppm compared to a preindustrial level of 285 ppm). In the present paper, we investigate the influence of vegetation change on the climate of the LGM by using a coupled atmosphere-ocean-vegetation general circulation model (AOVGCM, the MIROC-LPJ). The MIROC-LPJ is different from earlier studies in the introduction of a bias correction method in individual running GCM experiments. We examined four GCM experiments (LGM and preindustrial, with and without vegetation feedback) and quantified the strength of the vegetation feedback during the LGM. The result shows that global-averaged cooling during the LGM is amplified by +13.5 % due to the introduction of vegetation feedback. This is mainly caused by the increase of land surface albedo due to the expansion of tundra in northern high latitudes and the desertification in northern middle latitudes around 30° N to 60° N. We also investigated how this change in climate affected the total terrestrial carbon storage by using offline Lund-Potsdam-Jena dynamic global vegetation model (LPJ-DGVM). Our result shows that the total terrestrial carbon storage was reduced by 597 PgC during the LGM, which corresponds to the emission of 282 ppm atmospheric CO2. In the LGM experiments, the global carbon distribution is generally the same whether the vegetation feedback to the atmosphere is included or not. However, the inclusion of vegetation feedback causes substantial terrestrial carbon storage change, especially in explaining the lowering of atmospheric CO2 during the LGM.

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Northern Sourced Water dominated the Atlantic Ocean during the Last Glacial Maximum

10.5194/egusphere-egu2020-1353 ◽

2020 ◽

Author(s):

Frerk Pöppelmeier ◽

Patrick Blaser ◽

Marcus Gutjahr ◽

Samuel Jaccard ◽

Martin Frank ◽

...

Keyword(s):

Carbon Storage ◽

Last Glacial Maximum ◽

Water Mass ◽

Stable Carbon Isotope ◽

Deep Ocean ◽

Glacial Maximum ◽

Ice Age ◽

Last Glacial ◽

The Last Glacial Maximum ◽

The Last Glacial

Increased carbon sequestration in the ocean subsurface is commonly assumed to have been one of the main causes responsible for lower glacial atmospheric CO2 concentrations. This carbon must have been stored away from the atmosphere for thousands of years, yet the water mass structure accommodating such increased carbon storage continues to be debated. Here we present new sediment derived bottom water neodymium isotope data that allow fingerprinting of water masses and their mixtures and provide a more complete picture of the Atlantic overturning circulation geometry during the Last Glacial Maximums. These results suggest that the vertical and meridional structure of the Atlantic deep water mass distribution only experienced minor changes since the last ice age. In particular, we find no compelling evidence supporting glacial southern sourced water substantially expanding to shallower depths and farther into the northern hemisphere than today, which has been inferred from stable carbon isotope reconstructions. We argue that depleted &#948;13C values observed in the deep Northwest Atlantic do not necessarily indicate the presence of southern sourced water. Instead, these values may represent a northern sourced water mass with lower than modern preformed &#948;13C values that were further modified downstream by increased sequestration of remineralized carbon, facilitated by a more sluggish glacial deep circulation. If proven to be correct, the glacial water mass structure inferred from Nd isotopes has profound implications on our understanding of the deep ocean carbon storage during the Last Glacial Maximum.

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Research Spotlight: Simulating ocean carbon storage during the Last Glacial Maximum

Eos ◽

10.1029/2011eo100011 ◽

2011 ◽

Vol 92 (10) ◽

pp. 88-88

Author(s):

Ernie Tretkoff

Keyword(s):

Carbon Storage ◽

Last Glacial Maximum ◽

Glacial Maximum ◽

Last Glacial ◽

Ocean Carbon ◽

The Last Glacial Maximum ◽

The Last Glacial

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Modelling Global Vegetation Patterns and Terrestrial Carbon Storage at the Last Glacial Maximum

Global Ecology and Biogeography Letters ◽

10.2307/2997548 ◽

1993 ◽

Vol 3 (3) ◽

pp. 67 ◽

Cited By ~ 110

Author(s):

I. Colin Prentice ◽

Martin T. Sykes ◽

Michael Lautenschlager ◽

Sandy P. Harrison ◽

Olga Denissenko ◽

...

Keyword(s):

Carbon Storage ◽

Last Glacial Maximum ◽

Glacial Maximum ◽

Vegetation Patterns ◽

Terrestrial Carbon ◽

Last Glacial ◽

Global Vegetation ◽

The Last Glacial Maximum ◽

The Last Glacial

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Carbon storage increases by major forest ecosystems in tropical South America since the Last Glacial Maximum and the early Holocene

Global and Planetary Change ◽

10.1016/s0921-8181(02)00065-6 ◽

2002 ◽

Vol 33 (1-2) ◽

pp. 107-116 ◽

Cited By ~ 36

Author(s):

Hermann Behling

Keyword(s):

South America ◽

Carbon Storage ◽

Last Glacial Maximum ◽

Forest Ecosystems ◽

Glacial Maximum ◽

Early Holocene ◽

Last Glacial ◽

The Last Glacial Maximum ◽

The Last Glacial ◽

Tropical South America

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The Biological Pump During the Last Glacial Maximum

Annual Review of Marine Science ◽

10.1146/annurev-marine-010419-010906 ◽

2020 ◽

Vol 12 (1) ◽

pp. 559-586 ◽

Cited By ~ 3

Author(s):

Eric D. Galbraith ◽

Luke C. Skinner

Keyword(s):

Carbon Storage ◽

Last Glacial Maximum ◽

Ocean Circulation ◽

Marine Ecosystem ◽

Glacial Maximum ◽

Ice Age ◽

Natural Experiments ◽

Last Glacial ◽

The Last Glacial Maximum ◽

The Last Glacial

Much of the global cooling during ice ages arose from changes in ocean carbon storage that lowered atmospheric CO2. A slew of mechanisms, both physical and biological, have been proposed as key drivers of these changes. Here we discuss the current understanding of these mechanisms with a focus on how they altered the theoretically defined soft-tissue and biological disequilibrium carbon storage at the peak of the last ice age. Observations and models indicate a role for Antarctic sea ice through its influence on ocean circulation patterns, but other mechanisms, including changes in biological processes, must have been important as well, and may have been coordinated through links with global air temperature. Further research is required to better quantify the contributions of the various mechanisms, and there remains great potential to use the Last Glacial Maximum and the ensuing global warming as natural experiments from which to learn about climate-driven changes in the marine ecosystem.

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