scholarly journals Constraints on long term warming in a climate mitigation scenario

2020 ◽  
Author(s):  
Benjamin Sanderson
Keyword(s):  
Carbon Budget ◽  
System Response ◽  
Climate Mitigation ◽  
Earth System ◽  
Mitigation Scenario ◽  
The Earth ◽  
Net Zero ◽  
Negative Emissions ◽  
Near Term

Abstract. Cumulative emissions budgets and net-zero emission target dates are often used to frame climate negotiations (Frameet al., 2014; Millar et al., 2016; Van Vuuren et al., 2016; Rogelj et al., 2015b; Matthews et al., 2012). However, their utilityfor near-term policy decisions is confounded by an uncertainties in future negative emissions capacity (Fuss et al., 2014; Smith et al., 2016; Larkin et al., 2018; Anderson and Peters, 2016) and in long term Earth System response to climate forcers(Rugenstein et al., 2019; Knutti et al., 2017; Armour, 2017) which may impact the utility of an indefinite carbon budget if peak temperatures occur significantly after net zero emissions are achieved, the likelihood of which in a simple model is conditionalon prior assumptions about the long term dynamics of the Earth System. Here we illustrate that the risks associated with nearterm positive emissions can be framed using a definite cumulative emissions budget with a 2040 time horizon, allowing thenecessity and scope for negative emissions deployment later in the century to be better informed by observed warming overcoming decades.

scholarly journals The role of prior assumptions in carbon budget calculations

2020 ◽  
Vol 11 (2) ◽  
pp. 563-577
Author(s):  
Benjamin Sanderson
Keyword(s):  
Carbon Budget ◽  
System Response ◽  
Earth System ◽  
Emissions Reductions ◽  
The Earth ◽  
Net Zero ◽  
Negative Emissions ◽  
Near Term

Abstract. Cumulative emissions budgets and net-zero emission target dates are often used to frame climate negotiations (Frame et al., 2014; Millar et al., 2016; Van Vuuren et al., 2016; Rogelj et al., 2015b; Matthews et al., 2012). However, their utility for near-term policy decisions is confounded by uncertainties in future negative emissions capacity (Fuss et al., 2014; Smith et al., 2016; Larkin et al., 2018; Anderson and Peters, 2016), in the role of non-CO2 forcers (MacDougall et al., 2015) and in the long-term Earth system response to forcing (Rugenstein et al., 2019; Knutti et al., 2017; Armour, 2017). Such uncertainties may impact the utility of an absolute carbon budget if peak temperatures occur significantly after net-zero emissions are achieved, the likelihood of which is shown here to be conditional on prior assumptions about the long-term dynamics of the Earth system. In the context of these uncertainties, we show that the necessity and scope for negative emissions deployment later in the century can be conditioned on near-term emissions, providing support for a scenario framework which focuses on emissions reductions rather than absolute budgets (Rogelj et al., 2019b).

scholarly journals Simulating the Earth system response to negative emissions

2016 ◽  
Vol 11 (9) ◽  
pp. 095012 ◽  
Author(s):  
C D Jones ◽  
P Ciais ◽  
S J Davis ◽  
P Friedlingstein ◽  
T Gasser ◽  
...  
Keyword(s):  
System Response ◽  
Earth System ◽  
The Earth ◽  
Negative Emissions

scholarly journals Effects of Earth system feedbacks on the potential mitigation of large-scale tropical forest restoration

2021 ◽  
Vol 18 (8) ◽  
pp. 2627-2647
Author(s):  
Alexander Koch ◽  
Chris Brierley ◽  
Simon L. Lewis
Keyword(s):  
Land Use ◽  
Carbon Cycle ◽  
Forest Restoration ◽  
Large Scale ◽  
Paris Agreement ◽  
System Response ◽  
Earth System ◽  
The Earth ◽  
Negative Emissions ◽  
The Tropics

Abstract. To achieve the Paris Agreement requires aggressive mitigation strategies alongside negative emission technologies. Recent studies suggest that increasing tree cover can make a substantial contribution to negative emissions, with the tropics being the most suitable region from a biogeophysical perspective. Yet these studies typically do not account for subsequent carbon cycle and climate responses to large-scale land-use change. Here we quantify the maximum potential temperature and CO2 benefits from pantropical forest restoration, including the Earth system response, using a fully coupled, emission-driven Earth system model (HadGEM2-ES). We perform an idealised experiment where all land use in the tropics is stopped and vegetation is allowed to recover, on top of an aggressive mitigation scenario (RCP2.6). We find that tropical restoration of 1529 Mha increases carbon stored in live biomass by 130 Pg C by 2100 CE. Whilst avoiding deforestation and tropical restoration in the tropics removes 42 Pg C compared to RCP2.6, the subsequent reduction in extratropical and ocean carbon uptake means that carbon in the atmosphere only reduces by 18 Pg C by 2100. The resulting small CO2 (9 ppm) benefit does not translate to a detectable reduction in global surface air temperature compared to the control experiment. The greatest carbon benefit is achieved 30–50 years after restoration before the Earth system response adjusts to the new land-use regime and declining fossil fuel use. Comparing our results with previous modelling studies, we identify two model-independent key points: (i) in a world where emission reductions follow the Paris Agreement, restoration is best deployed immediately, and (ii) the global carbon cycle response to reduced emissions limits the efficacy of negative emissions technologies by more than half. We conclude that forest restoration can reduce peak CO2 mid-century, but it can only modestly contribute to negative emissions.

Is Climate Change Reversible? CDRMIP simulations of the Earth system response to a massive CO2 increase and decrease (emissions followed by negative emissions).

2020 ◽  
Author(s):  
David Keller ◽  
Andrew Lenton ◽  
Vivian Scott ◽  
Naomi Vaughan ◽  
Keyword(s):  
Climate Change ◽  
Local Level ◽  
Climate Change Impacts ◽  
System Response ◽  
Time Lags ◽  
Earth System ◽  
The Earth ◽  
Long Time ◽  
Industrial Level

<p>To stabilize long-term climate change at well-below 2°C (ideally below 1.5°C) above pre-industrial levels, large and sustained CO<sub>2</sub> emission reductions are needed.  Despite pledges from numerous governments, the world is not on track to achieve the required reductions within the timeframes outlined in the Paris Agreement, and it appears increasingly likely that an overshoot of the 1.5 or 2 °C temperature target will occur.  If this happens, it may be possible to use carbon dioxide removal methods to return atmospheric CO<sub>2</sub> concentrations to lower levels or even to reduce the magnitude of the overshoot, with the hope that lower CO<sub>2</sub> will rapidly lead to lower temperatures and reverse or limit other climate change impacts.  Here we present a multi-model analysis of how the Earth system and climate respond during the CMIP6 CDRMIP cdr-reversibility experiment, an idealized overshoot scenario, where CO<sub>2</sub> increases from a pre-industrial level by 1% yr<sup>-1</sup> until it is 4 times the initial value, then decrease again at 1% yr<sup>-1</sup> until the pre-industrial level is again reached, at which point CO<sub>2</sub> is held constant.  For many modelled quantities climate change appears to eventually be reversible, at least when viewed at the global mean level.  However, at a local level the results suggest some changes may be irreversible, although spatial patterns of change differ considerably between models.  For many variables the response time-scales to the CO<sub>2</sub> increase are very different than to the decrease in CO<sub>2</sub> with a many properties exhibiting long time lags before responding to decreasing CO<sub>2</sub>, and much longer again to return to their unperturbed values (if this occurs).</p>

scholarly journals Geosystemics and Earthquakes

2018 ◽  
Author(s):  
Angelo De Santis ◽  
Gianfranco Cianchini ◽  
Rita Di Giovambattista ◽  
Cristoforo Abbattista ◽  
Lucilla Alfonsi ◽  
...  
Keyword(s):  
Dynamical System ◽  
Solid Earth ◽  
Case Studies ◽  
Central Italy ◽  
Point Of View ◽  
Earth System ◽  
Complex Dynamical System ◽  
The Earth ◽  
Earth’S Interior

Abstract. Geosystemics (De Santis 2009, 2014) studies the Earth system as a whole focusing on the possible coupling among the Earth layers (the so called geo-layers), and using universal tools to integrate different methods that can be applied to multi-parameter data, often taken on different platforms. Its main objective is to understand the particular phenomenon of interest from a holistic point of view. In this paper we will deal with earthquakes, considered as a long term chain of processes involving, not only the interaction between different components of the Earth’s interior, but also the coupling of the solid earth with the above neutral and ionized atmosphere, and finally culminating with the main rupture along the fault of concern (De Santis et al., 2015a). Some case studies (particular emphasis is given to recent central Italy earthquakes) will be discussed in the frame of the geosystemic approach for better understanding the physics of the underlying complex dynamical system.

The role of the Microbial Conveyor Belt on Earth´s system resilience

2021 ◽  
Author(s):  
Mireia Mestre ◽  
Juan Höfer
Keyword(s):  
Human Impacts ◽  
Conveyor Belt ◽  
Earth System ◽  
Planetary Scale ◽  
Microbial Biogeography ◽  
The Earth ◽  
System Resilience ◽  
Global Biogeochemical Cycles

<p>Despite being major players on the global biogeochemical cycles, microorganisms are generally not included in holistic views of Earth’s system. The Microbial Conveyor Belt is a conceptual framework that represents a recurrent and cyclical flux of microorganisms across the globe, connecting distant ecosystems and Earth compartments. This long-range dispersion of microorganisms directly influences the microbial biogeography, the global cycling of inorganic and organic matter, and thus the Earth system’s functioning and long-term resilience. Planetary-scale human impacts disrupting the natural flux of microorganisms pose a major threat to the Microbial Conveyor Belt, thus compromising microbial ecosystem services. Perturbations that modify the natural dispersion of microorganisms are, for example, the modification of the intensity/direction of air fluxes and ocean currents due to climate change, the vanishing of certain dispersion vectors (e.g., species extinction or drying rivers) or the introduction of new ones (e.g., microplastics, wildfires). Transdisciplinary approaches are needed to disentangle the Microbial Conveyor Belt, its major threats and their consequences for Earth´s system resilience.</p>

scholarly journals Deep-time organizations: Learning institutional longevity from history

2019 ◽  
Vol 7 (1) ◽  
pp. 19-41 ◽  
Author(s):  
Frederic Hanusch ◽  
Frank Biermann
Keyword(s):  
Empirical Research ◽  
Design Principles ◽  
Earth System ◽  
Political Organizations ◽  
Deep Time ◽  
Initial Design ◽  
Earth System Governance ◽  
The Earth ◽  
Temporal Interdependencies

The Anthropocene as a new planetary epoch has brought to the foreground the deep-time interconnections of human agency with the earth system. Yet despite this recognition of strong temporal interdependencies, we still lack understanding of how societal and political organizations can manage interconnections that span several centuries and dozens of generations. This study pioneers the analysis of what we call “deep-time organizations.” We provide detailed comparative historical analyses of some of the oldest existing organizations worldwide from a variety of sectors, from the world’s oldest bank (Sveriges Riksbank) to the world’s oldest university (University of Al Quaraouiyine) and the world’s oldest dynasty (Imperial House of Japan). Based on our analysis, we formulate 12 initial design principles that could lay, if supported by further empirical research along similar lines, the basis for the construction and design of “deep-time organizations” for long-term challenges of earth system governance and planetary stewardship.

scholarly journals Geosystemics View of Earthquakes

Entropy ◽  
2019 ◽  
Vol 21 (4) ◽  
pp. 412 ◽  
Author(s):  
Angelo De Santis ◽  
Cristoforo Abbattista ◽  
Lucilla Alfonsi ◽  
Leonardo Amoruso ◽  
Saioa A. Campuzano ◽  
...  
Keyword(s):  
Solid Earth ◽  
Point Of View ◽  
Satellite Observations ◽  
Earth System ◽  
Seismic Sequences ◽  
The Earth ◽  
Earth’S Interior ◽  
Earth's Interior ◽  
Physical Quantities

Earthquakes are the most energetic phenomena in the lithosphere: their study and comprehension are greatly worth doing because of the obvious importance for society. Geosystemics intends to study the Earth system as a whole, looking at the possible couplings among the different geo-layers, i.e., from the earth’s interior to the above atmosphere. It uses specific universal tools to integrate different methods that can be applied to multi-parameter data, often taken on different platforms (e.g., ground, marine or satellite observations). Its main objective is to understand the particular phenomenon of interest from a holistic point of view. Central is the use of entropy, together with other physical quantities that will be introduced case by case. In this paper, we will deal with earthquakes, as final part of a long-term chain of processes involving, not only the interaction between different components of the Earth’s interior but also the coupling of the solid earth with the above neutral or ionized atmosphere, and finally culminating with the main rupture along the fault of concern. Particular emphasis will be given to some Italian seismic sequences.

scholarly journals The role of negative emissions in meeting China’s 2060 carbon neutrality goal

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Jay Fuhrman ◽  
Andres F Clarens ◽  
Haewon McJeon ◽  
Pralit Patel ◽  
Yang Ou ◽  
...  
Keyword(s):  
Carbon Capture ◽  
Carbon Capture And Storage ◽  
Climate Mitigation ◽  
Analysis Model ◽  
Change Analysis ◽  
Carbon Neutrality ◽  
Net Zero ◽  
Negative Emissions ◽  
Air Capture

Abstract China’s pledge to reach carbon neutrality before 2060 is an ambitious goal and could provide the world with much-needed leadership on how to limit warming to +1.5°C warming above preindustrial levels by the end of the century. But the pathways that would achieve net zero by 2060 are still unclear, including the role of negative emissions technologies. We use the Global Change Analysis Model to simulate how negative emissions technologies, in general, and direct air capture (DAC) in particular, could contribute to China’s meeting this target. Our results show that negative emissions could play a large role, offsetting on the order of 3 GtCO2 per year from difficult-to-mitigate sectors, such as freight transportation and heavy industry. This includes up to a 1.6 GtCO2 per year contribution from DAC, constituting up to 60% of total projected negative emissions in China. But DAC, like bioenergy with carbon capture and storage and afforestation, has not yet been demonstrated anywhere approaching the scales required to meaningfully contribute to climate mitigation. Deploying NETs at these scales will have widespread impacts on financial systems and natural resources, such as water, land and energy in China.

scholarly journals Earth system feedbacks following large-scale tropical forest restoration

2020 ◽  
Author(s):  
Alexander Koch ◽  
Chris Brierley ◽  
Simon L. Lewis
Keyword(s):  
Land Use ◽  
Forest Restoration ◽  
Large Scale ◽  
Paris Agreement ◽  
Climate Feedback ◽  
Substantial Contribution ◽  
System Response ◽  
Earth System ◽  
Negative Emissions ◽  
The Tropics

Abstract. To achieve the Paris Agreement requires aggressive mitigation strategies alongside negative emission technologies. Recent studies suggest that increasing tree cover can make a substantial contribution to negative emissions, with the tropics being the most suitable region from a biogeophysical perspective. Yet these studies typically do not account for subsequent carbon cycle and climate feedback processes of large-scale land use change. Here we quantify the maximum potential temperature and CO2 benefits from pantropical forest restoration, including earth system feedbacks, using a fully-coupled, emission-driven Earth System Model (HadGEM2-ES). We perform an idealised experiment where all land use in the tropics is stopped and vegetation is allowed to recover, on top of an aggressive mitigation scenario (RCP 2.6). We find that tropical restoration of 1529 Mha increases carbon stored in live biomass by 130 Pg C by 2100 CE. Whilst avoiding deforestation and tropical restoration in the tropics removes 42 Pg C compared to RCP 2.6, feedback processes mean that carbon in the atmosphere only reduces by 18 Pg C by 2100. The resulting, small CO2 (9 ppm) benefit does not translate to a detectable reduction in global surface air temperature compared to the control experiment. The greatest carbon benefit is achieved 30–50 years after restoration before the Earth System response adjusts to the new land-use regime and declining fossil fuel use. We identify three model-independent key points: (i) the carbon benefit of restoration is CO2-scenario dependent, (ii) in a world that follows Paris Agreement emission cuts restoration is best deployed immediately, and (iii) the ocean carbon feedbacks will reduce the efficacy of negative emissions technologies. We conclude that forest restoration can reduce peak CO2 mid-century, but can only be a modest contribution to negative emissions.

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