Sensitivity of a coupled climate-carbon cycle model to large volcanic eruptions during the last millennium

Abstract. Using a fully coupled global climate-carbon cycle model, we assess the potential role of volcanic eruptions on future projection of climate change and its associated carbon cycle feedback. The volcanic-like forcings are applied together with business-as-usual IPCC-A2 carbon emissions scenario. We show that very large volcanic eruptions similar to Tambora lead to short-term substantial global cooling. However, over a long period, smaller but more frequent eruptions, such as Pinatubo, would have a stronger impact on future climate change. In a scenario where the volcanic external forcings are prescribed with a five-year frequency, the induced cooling immediately lower the global temperature by more than one degree before return to the warming trend. Therefore, the climate change is approximately delayed by several decades and by the end of the 21st century, the warming is still below two degrees when compared to the present day period. The cooler climate reduces the terrestrial heterotrophic respiration in the northern high latitude and increases net primary production in the tropics, which contributes to more than 45% increase in accumulated carbon uptake over land. The increased solubility of CO2 gas in seawater associated with cooler SST is offset by reduced CO2 partial pressure gradient between ocean and atmosphere, which results in small changes in net ocean carbon uptake. Similarly, there is nearly no change in the seawater buffer capacity simulated between the different volcanic scenarios. Our study shows that even in the relatively extreme scenario where large volcanic eruptions occur every five-years period, the induced cooling only leads to a reduction of 46 ppmv atmospheric CO2 concentration as compared to the reference projection of 878 ppmv, at the end of the 21st century. With respect to sulphur injection geoengineering method, our study suggest that small scale but frequent mitigation is more efficient than the opposite. Moreover, the longer we delay, the more difficult it would be to counteract climate change.

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Role of volcanic forcing on future global carbon cycle

Earth System Dynamics ◽

10.5194/esd-2-53-2011 ◽

2011 ◽

Vol 2 (1) ◽

pp. 53-67 ◽

Cited By ~ 9

Author(s):

J. F. Tjiputra ◽

O. H. Otterå

Keyword(s):

Climate Change ◽

Carbon Cycle ◽

21St Century ◽

Volcanic Eruptions ◽

Future Climate Change ◽

Feedback Signal ◽

Carbon Uptake ◽

Carbon Cycle Model ◽

Large Volcanic Eruptions

Abstract. Using a fully coupled global climate-carbon cycle model, we assess the potential role of volcanic eruptions on future projection of climate change and its associated carbon cycle feedback. The volcanic-like forcings are applied together with a business-as-usual IPCC-A2 carbon emissions scenario. We show that very large volcanic eruptions similar to Tambora lead to short-term substantial global cooling. However, over a long period, smaller eruptions similar to Pinatubo in amplitude, but set to occur frequently, would have a stronger impact on future climate change. In a scenario where the volcanic external forcings are prescribed with a five-year frequency, the induced cooling immediately lower the global temperature by more than one degree before it returns to the warming trend. Therefore, the climate change is approximately delayed by several decades, and by the end of the 21st century, the warming is still below two degrees when compared to the present day period. Our climate-carbon feedback analysis shows that future volcanic eruptions induce positive feedbacks (i.e., more carbon sink) on both the terrestrial and oceanic carbon cycle. The feedback signal on the ocean is consistently smaller than the terrestrial counterpart and the feedback strength is proportionally related to the frequency of the volcanic eruption events. The cooler climate reduces the terrestrial heterotrophic respiration in the northern high latitude and increases net primary production in the tropics, which contributes to more than 45 % increase in accumulated carbon uptake over land. The increased solubility of CO2 gas in seawater associated with cooler SST is offset by a reduced CO2 partial pressure gradient between the ocean and the atmosphere, which results in small changes in net ocean carbon uptake. Similarly, there is nearly no change in the seawater buffer capacity simulated between the different volcanic scenarios. Our study shows that even in the relatively extreme scenario where large volcanic eruptions occur every five-years period, the induced cooling leads to a reduction of 46 ppmv atmospheric CO2 concentration as compared to the reference projection of 878 ppmv, at the end of the 21st century.

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Designing and Implementing an Online Carbon Cycle Model Service Platform Based on OGC Web Processing Service

Geo-information Science ◽

10.3724/sp.j.1047.2012.00320 ◽

2012 ◽

Vol 14 (3) ◽

pp. 320-326

Author(s):

Nan WU ◽

Honglin HE ◽

Li ZHANG ◽

Xiaoli REN ◽

Yuanchun ZHOU ◽

...

Keyword(s):

Carbon Cycle ◽

Cycle Model ◽

Service Platform ◽

Carbon Cycle Model ◽

Processing Service

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A record of Neogene seawater δ11B reconstructed from paired δ11B analyses on benthic and planktic foraminifera

Climate of the Past ◽

10.5194/cp-13-149-2017 ◽

2017 ◽

Vol 13 (2) ◽

pp. 149-170 ◽

Cited By ~ 17

Author(s):

Rosanna Greenop ◽

Mathis P. Hain ◽

Sindia M. Sosdian ◽

Kevin I. C. Oliver ◽

Philip Goodwin ◽

...

Keyword(s):

Carbon Cycle ◽

Middle Miocene ◽

Isotope Composition ◽

Boron Isotope ◽

Mineral Formation ◽

Secondary Mineral ◽

Cycle Model ◽

Planktic Foraminifera ◽

Carbon Cycle Model ◽

Secondary Mineral Formation

Abstract. The boron isotope composition (δ11B) of foraminiferal calcite reflects the pH and the boron isotope composition of the seawater the foraminifer grew in. For pH reconstructions, the δ11B of seawater must therefore be known, but information on this parameter is limited. Here we reconstruct Neogene seawater δ11B based on the δ11B difference between paired measurements of planktic and benthic foraminifera and an estimate of the coeval water column pH gradient from their δ13C values. Carbon cycle model simulations underscore that the ΔpH–Δδ13C relationship is relatively insensitive to ocean and carbon cycle changes, validating our approach. Our reconstructions suggest that δ11Bsw was ∼  37.5 ‰ during the early and middle Miocene (roughly 23–12 Ma) and rapidly increased during the late Miocene (between 12 and 5 Ma) towards the modern value of 39.61 ‰. Strikingly, this pattern is similar to the evolution of the seawater isotope composition of Mg, Li and Ca, suggesting a common forcing mechanism. Based on the observed direction of change, we hypothesize that an increase in secondary mineral formation during continental weathering affected the isotope composition of riverine input to the ocean since 14 Ma.

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Multicentury Changes to the Global Climate and Carbon Cycle: Results from a Coupled Climate and Carbon Cycle Model

Journal of Climate ◽

10.1175/jcli3542.1 ◽

2005 ◽

Vol 18 (21) ◽

pp. 4531-4544 ◽

Cited By ~ 37

Author(s):

G. Bala ◽

K. Caldeira ◽

A. Mirin ◽

M. Wickett ◽

C. Delire

Keyword(s):

Carbon Cycle ◽

Radiative Forcing ◽

Fossil Fuel ◽

Global Climate ◽

Second Century ◽

Cycle Model ◽

Carbon Cycle Model ◽

Living Biomass ◽

Long Term Consequences

Abstract A coupled climate and carbon (CO2) cycle model is used to investigate the global climate and carbon cycle changes out to the year 2300 that would occur if CO2 emissions from all the currently estimated fossil fuel resources were released to the atmosphere. By the year 2300, the global climate warms by about 8 K and atmospheric CO2 reaches 1423 ppmv. The warming is higher than anticipated because the sensitivity to radiative forcing increases as the simulation progresses. In this simulation, the rate of emissions peaks at over 30 Pg C yr−1 early in the twenty-second century. Even at the year 2300, nearly 50% of cumulative emissions remain in the atmosphere. Both soils and living biomass are net carbon sinks throughout the simulation. Despite having relatively low climate sensitivity and strong carbon uptake by the land biosphere, these model projections suggest severe long-term consequences for global climate if all the fossil fuel carbon is ultimately released into the atmosphere.

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Climate and carbon cycle dynamics in a CESM simulation from 850–2100 CE

Earth System Dynamics Discussions ◽

10.5194/esdd-6-351-2015 ◽

2015 ◽

Vol 6 (1) ◽

pp. 351-406 ◽

Cited By ~ 3

Author(s):

F. Lehner ◽

F. Joos ◽

C. C. Raible ◽

J. Mignot ◽

A. Born ◽

...

Keyword(s):

Carbon Cycle ◽

Volcanic Eruptions ◽

Internal Variability ◽

Total Solar Irradiance ◽

Historical Period ◽

Last Millennium ◽

Coupled Modelling ◽

Decadal Scale ◽

Current Century ◽

Ocean Carbon

Abstract. Under the protocols of the Paleoclimate and Coupled Modelling Intercomparison Projects a number of simulations were produced that provide a range of potential climate evolutions from the last millennium to the end of the current century. Here, we present the first simulation with the Community Earth System Model (CESM), which includes an interactive carbon cycle, that continuously covers the last millennium, the historical period, and the twenty-first century. Besides state-of-the-art forcing reconstructions, we apply a modified reconstruction of total solar irradiance to shed light on the issue of forcing uncertainty in the context of the last millennium. Nevertheless, we find that structural uncertainties between different models can still dominate over forcing uncertainty for quantities such as hemispheric temperatures or the land and ocean carbon cycle response. Comparing with other model simulations we find forced decadal-scale variability to occur mainly after volcanic eruptions, while during other periods internal variability masks potentially forced signals and calls for larger ensembles in paleoclimate modeling studies. At the same time, we fail to attribute millennial temperature trends to orbital forcing, as has been suggested recently. The climate-carbon cycle sensitivity in CESM during the last millennium is estimated to be about 1.3 ppm °C−1. However, the dependence of this sensitivity on the exact time period and scale illustrates the prevailing challenge of deriving robust constrains on this quantity from paleoclimate proxies. In particular, the response of the land carbon cycle to volcanic forcing shows fundamental differences between different models. In CESM the tropical land dictates the response to volcanoes with a distinct behavior for large and moderate eruptions. Under anthropogenic emissions, global land and ocean carbon uptake rates emerge from the envelope of interannual natural variability as simulated for the last millennium by about year 1947 and 1877, respectively.

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Global carbonate accumulation rates from Cretaceous to Present and their implications for the carbon cycle model

Island Arc ◽

10.1046/j.1440-1738.2001.00276.x ◽

2001 ◽

Vol 10 (1) ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

T. Nakamori

Keyword(s):

Carbon Cycle ◽

Accumulation Rates ◽

Cycle Model ◽

Carbon Cycle Model

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Analytically tractable climate-carbon cycle feedbacks under 21st century anthropogenic forcing

10.5194/esd-2017-78 ◽

2017 ◽

Author(s):

Steven J. Lade ◽

Jonathan F. Donges ◽

Ingo Fetzer ◽

John M. Anderies ◽

Christian Beer ◽

...

Keyword(s):

Carbon Cycle ◽

Model Test ◽

Global Climate ◽

Earth System ◽

Planetary Boundaries ◽

Cycle Model ◽

Carbon Cycle Model ◽

The Earth ◽

Analytical Expressions ◽

Earth System Models

Abstract. Changes to climate-carbon cycle feedbacks may significantly affect the Earth System’s response to greenhouse gas emissions. These feedbacks are usually analysed from numerical output of complex and arguably opaque Earth System Models (ESMs). Here, we construct a stylized global climate-carbon cycle model, test its output against complex ESMs, and investigate the strengths of its climate-carbon cycle feedbacks analytically. The analytical expressions we obtain aid understanding of carbon-cycle feedbacks and the operation of the carbon cycle. We use our results to analytically study the relative strengths of different climate-carbon cycle feedbacks and how they may change in the future, as well as to compare different feedback formalisms. Simple models such as that developed here also provide workbenches for simple but mechanistically based explorations of Earth system processes, such as interactions and feedbacks between the Planetary Boundaries, that are currently too uncertain to be included in complex ESMs.

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C4MIP – The Coupled Climate–Carbon Cycle Model Intercomparison Project: experimental protocol for CMIP6

Geoscientific Model Development ◽

10.5194/gmd-9-2853-2016 ◽

2016 ◽

Vol 9 (8) ◽

pp. 2853-2880 ◽

Cited By ~ 67

Author(s):

Chris D. Jones ◽

Vivek Arora ◽

Pierre Friedlingstein ◽

Laurent Bopp ◽

Victor Brovkin ◽

...

Keyword(s):

Experimental Design ◽

Carbon Cycle ◽

Boundary Conditions ◽

Anthropogenic Activity ◽

Climate Modelling ◽

Model Intercomparison ◽

Cycle Model ◽

Carbon Cycle Model ◽

Intercomparison Project ◽

Set Up

Abstract. Coordinated experimental design and implementation has become a cornerstone of global climate modelling. Model Intercomparison Projects (MIPs) enable systematic and robust analysis of results across many models, by reducing the influence of ad hoc differences in model set-up or experimental boundary conditions. As it enters its 6th phase, the Coupled Model Intercomparison Project (CMIP6) has grown significantly in scope with the design and documentation of individual simulations delegated to individual climate science communities. The Coupled Climate–Carbon Cycle Model Intercomparison Project (C4MIP) takes responsibility for design, documentation, and analysis of carbon cycle feedbacks and interactions in climate simulations. These feedbacks are potentially large and play a leading-order contribution in determining the atmospheric composition in response to human emissions of CO2 and in the setting of emissions targets to stabilize climate or avoid dangerous climate change. For over a decade, C4MIP has coordinated coupled climate–carbon cycle simulations, and in this paper we describe the C4MIP simulations that will be formally part of CMIP6. While the climate–carbon cycle community has created this experimental design, the simulations also fit within the wider CMIP activity, conform to some common standards including documentation and diagnostic requests, and are designed to complement the CMIP core experiments known as the Diagnostic, Evaluation and Characterization of Klima (DECK). C4MIP has three key strands of scientific motivation and the requested simulations are designed to satisfy their needs: (1) pre-industrial and historical simulations (formally part of the common set of CMIP6 experiments) to enable model evaluation, (2) idealized coupled and partially coupled simulations with 1 % per year increases in CO2 to enable diagnosis of feedback strength and its components, (3) future scenario simulations to project how the Earth system will respond to anthropogenic activity over the 21st century and beyond. This paper documents in detail these simulations, explains their rationale and planned analysis, and describes how to set up and run the simulations. Particular attention is paid to boundary conditions, input data, and requested output diagnostics. It is important that modelling groups participating in C4MIP adhere as closely as possible to this experimental design.

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Sensitivity of a coupled climate-carbon cycle model to large volcanic eruptions during the last millennium