Towards a quantification of the water planetary boundary

2020 ◽  
Author(s):  
Lan Wang-Erlandsson ◽  
Tom Gleeson ◽  
Fernando Jaramillo ◽  
Samuel C. Zipper ◽  
Dieter Gerten ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Scientific Evidence ◽  
Terrestrial Ecosystems ◽  
Evaluation Framework ◽  
Earth System ◽  
Top Down ◽  
Bottom Up ◽  
Weighting Factors ◽  
The Earth ◽  
The Stability

<p>The planetary boundaries framework defines nine Earth system processes that together demarcate a safe operating space for humanity at the planetary scale. Freshwater - the bloodstream of the biosphere - is an obvious member of the planetary boundary framework.  Water fluxes and stores play a key role for the stability of the Earth’s climate and the world’s aquatic and terrestrial ecosystems. Recent work has proposed to represent the water planetary boundary through six sub-boundaries based on the five primary water stores, i.e., atmospheric water, soil moisture, surface water, groundwater, and frozen water. In order to make it usable on all spatial scales we examine bottom-up and top-down approaches for quantification of the water planetary boundary. For the bottom-up approaches, we explore possible spatially distributed variables defining each of the proposed sub-boundaries, as well as possible weighting factors and keystone regions that can be used for aggregation of the distributed water sub-boundaries to the global scale. For the top-down approaches, we re-examine the stability of key biomes and tipping elements in the Earth System that may be crucially influenced by water cycle modifications. To identify the most appropriate variables for representing the water planetary boundary, we evaluate the range of explored variables with regard to scientific evidence and scientific representation using a hierarchy-based evaluation framework. Finally, we compare the highest ranked top-down and bottom-up approaches in terms of the scientific outcome and implications for governance. In sum, this comprehensive and systematic identification and evaluation of variables, weighting factors, and baseline conditions provides a detailed basis for the future operational quantification of the water planetary boundary. </p>

Phanerozoic marine faunas and the stability of the earth system

1989 ◽  
Vol 1 (1-2) ◽  
pp. 137-155
Author(s):  
James W. Valentine
Keyword(s):  
Earth System ◽  
The Earth ◽  
The Stability

scholarly journals Towards a more objective evaluation of modelled land-carbon trends using atmospheric CO<sub>2</sub> and satellite-based vegetation activity observations

2013 ◽  
Vol 10 (6) ◽  
pp. 4189-4210 ◽  
Author(s):  
D. Dalmonech ◽  
S. Zaehle
Keyword(s):  
Land Surface ◽  
Climate Model ◽  
Spatial Scales ◽  
Evaluation Framework ◽  
Atmospheric Co2 ◽  
Evaluation Methodology ◽  
Surface Model ◽  
System Modelling ◽  
Earth System ◽  
Vegetation Activity

Abstract. Terrestrial ecosystem models used for Earth system modelling show a significant divergence in future patterns of ecosystem processes, in particular the net land–atmosphere carbon exchanges, despite a seemingly common behaviour for the contemporary period. An in-depth evaluation of these models is hence of high importance to better understand the reasons for this disagreement. Here, we develop an extension for existing benchmarking systems by making use of the complementary information contained in the observational records of atmospheric CO2 and remotely sensed vegetation activity to provide a novel set of diagnostics of ecosystem responses to climate variability in the last 30 yr at different temporal and spatial scales. The selection of observational characteristics (traits) specifically considers the robustness of information given that the uncertainty of both data and evaluation methodology is largely unknown or difficult to quantify. Based on these considerations, we introduce a baseline benchmark – a minimum test that any model has to pass – to provide a more objective, quantitative evaluation framework. The benchmarking strategy can be used for any land surface model, either driven by observed meteorology or coupled to a climate model. We apply this framework to evaluate the offline version of the MPI Earth System Model's land surface scheme JSBACH. We demonstrate that the complementary use of atmospheric CO2 and satellite-based vegetation activity data allows pinpointing of specific model deficiencies that would not be possible by the sole use of atmospheric CO2 observations.

How Plants Enhance Weathering and How Weathering is Important to Plants

Elements ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 241-246 ◽  
Author(s):  
Stephen Porder
Keyword(s):  
Terrestrial Ecosystems ◽  
Carbon Uptake ◽  
Rock Weathering ◽  
Earth System ◽  
Agricultural Systems ◽  
Carbon Loss ◽  
Weathering Rates ◽  
Environmental Consequences ◽  
The Earth ◽  
Primary Minerals

Since land plants emerged from swampy coastlines over 400 million years ago, they have played a fundamental role in shaping the Earth system. Roots and associated fungi increase rock weathering rates, providing access to nutrients, while altering atmospheric CO2. As soils weather, the dissolution of primary minerals forces plants to rely on recycling and atmospheric deposition of rock-derived nutrients. Thus, for many terrestrial ecosystems, weathering ultimately constrains primary production (carbon uptake) and decomposition (carbon loss). These constraints are most acute in agricultural systems, which rely on mined fertilizer rather than the recycling of organic material to maintain production. Humans now mine similar amounts of some elements as weather out of rocks globally. This increase in supply has myriad environmental consequences.

scholarly journals On observational and modelling strategies targeted at regional carbon exchange over continents

2009 ◽  
Vol 6 (1) ◽  
pp. 1317-1343 ◽  
Author(s):  
C. Gerbig ◽  
A. J. Dolman ◽  
M. Heimann
Keyword(s):  
Spatial Scales ◽  
Regional Scale ◽  
Local Scale ◽  
Anthropogenic Sources ◽  
Carbon Exchange ◽  
Top Down ◽  
Bottom Up ◽  
Modelling Strategies ◽  
The Impact ◽  
Up Scaling

Abstract. Estimating carbon exchange at regional scales is paramount to understanding feedbacks between climate and the carbon cycle, but also to verifying climate change mitigation such as emission reductions and strategies compensating for emissions such as carbon sequestration. This paper discusses evidence for a number of important shortcomings of current generation modelling frameworks designed to provide regional scale budgets. Current top-down and bottom-up approaches targeted at deriving consistent regional scale carbon exchange estimates for biospheric and anthropogenic sources and sinks are hampered by a number of issues: We show that top-down constraints using point measurements made from tall towers, although sensitive to larger spatial scales, are however influenced by local areas much stronger than previously thought. On the other hand, classical bottom-up approaches using process information collected at the local scale, such as from eddy covariance data, need up-scaling and validation on larger scales. We therefore argue for a combination of both approaches, implicitly providing the important local scale information for the top-down constraint, and providing the atmospheric constraint for up-scaling of flux measurements. Combining these data streams necessitates quantifying their respective representation errors, which are discussed. The impact of these findings on future network design is highlighted, and some recommendations are given.

scholarly journals Spatial frameworks for robust estimation of yield gaps

Nature Food ◽  
2021 ◽  
Author(s):  
Juan I. Rattalino Edreira ◽  
José F. Andrade ◽  
Kenneth G. Cassman ◽  
Martin K. van Ittersum ◽  
Marloes P. van Loon ◽  
...  
Keyword(s):  
Food Security ◽  
Crop Production ◽  
Spatial Scales ◽  
Sub Saharan Africa ◽  
Yield Potential ◽  
Top Down ◽  
Yield Gap ◽  
Bottom Up ◽  
Improvement Project ◽  
Yield Gaps

AbstractFood security interventions and policies need reliable estimates of crop production and the scope to enhance production on existing cropland. Here we assess the performance of two widely used ‘top-down’ gridded frameworks (Global Agro-ecological Zones and Agricultural Model Intercomparison and Improvement Project) versus an alternative ‘bottom-up’ approach (Global Yield Gap Atlas). The Global Yield Gap Atlas estimates extra production potential locally for a number of sites representing major breadbaskets and then upscales the results to larger spatial scales. We find that estimates from top-down frameworks are alarmingly unlikely, with estimated potential production being lower than current farm production at some locations. The consequences of using these coarse estimates to predict food security are illustrated by an example for sub-Saharan Africa, where using different approaches would lead to different prognoses about future cereal self-sufficiency. Our study shows that foresight about food security and associated agriculture research priority setting based on yield potential and yield gaps derived from top-down approaches are subject to a high degree of uncertainty and would benefit from incorporating estimates from bottom-up approaches.

scholarly journals Systematic Correlation Matrix Evaluation (SCoMaE) – A bottom-up, natural science-based approach to identify Indicators

2017 ◽  
Author(s):  
Nadine Mengis ◽  
David P. Keller ◽  
Andreas Oschlies
Keyword(s):  
Climate Change ◽  
Correlation Matrix ◽  
Expert Judgment ◽  
Comparative Assessment ◽  
Systematic Evaluation ◽  
Climate Change Scenarios ◽  
Scenario Simulation ◽  
Earth System ◽  
Bottom Up ◽  
The Earth

Abstract. This study introduces the Systematic Correlation Matrix Evaluation (SCoMaE) method, a bottom-up approach which combines expert judgment and statistical information to systematically select transparent, non redundant indicators for a com- prehensive assessment of the state of the Earth system. The methods consists of three basic steps: 1) Calculation of a correlation matrix among variables relevant for a given research question, 2) Systematic evaluation of the matrix, to identify clusters of variables with similar behavior and respective mutually independent indicators, and 3) Interpretation of the identified clusters, enabling a learning effect from the selection of indicators. Optional further analysis steps include: 4) Testing the robustness of identified clusters with respect to changes in forcing or boundary conditions, 5) Enabling a comparative assessment of varying scenarios by constructing and evaluating a common correlation matrix, or 6) Inclusion of expert judgment such as to prescribe indicators, to allow for considerations other than statistical consistency. The exemplary application of the SCoMaE method to Earth system model output forced by different CO2 emission scenarios reveals the necessity of re-evaluating indicators identified in a historical scenario simulation for an accurate assessment of an intermediate-high, as well as a business-as-usual, climate change scenario simulation, which arises from changes in prevailing correlations in the Earth system under varying climate forcing. For a comparative assessment of the three climate change scenarios, we construct and evaluate a common correlation matrix, in which we identify robust correlations between variables across the three considered scenarios.

scholarly journals Constraints from atmospheric CO<sub>2</sub> and satellite-based vegetation activity observations on current land carbon cycle trends

2012 ◽  
Vol 9 (11) ◽  
pp. 16087-16138 ◽  
Author(s):  
D. Dalmonech ◽  
S. Zaehle
Keyword(s):  
Land Surface ◽  
Climate Model ◽  
Spatial Scales ◽  
Evaluation Framework ◽  
Atmospheric Co2 ◽  
Surface Model ◽  
System Modelling ◽  
Earth System ◽  
Activity Data ◽  
Vegetation Activity

Abstract. Terrestrial ecosystem models used for Earth system modelling show a significant divergence in future patterns of ecosystem processes, in particular carbon exchanges, despite a seemingly common behaviour for the contemporary period. An in-depth evaluation of these models is hence of high importance to achieve a better understanding of the reasons for this disagreement. Here, we develop an extension for existing benchmarking systems by making use of the complementary information contained in the observational records of atmospheric CO2 and remotely-sensed vegetation activity to provide a firm set of diagnostics of ecosystem responses to climate variability in the last 30 yr at different temporal and spatial scales. The selection of observational characteristics (traits) specifically considers the robustness of information given the uncertainties in both data and evaluation analysis. In addition, we provide a baseline benchmark, a minimum test that the model under consideration has to pass, to provide a more objective, quantitative evaluation framework. The benchmarking strategy can be used for any land surface model, either driven by observed meteorology or coupled to a climate model. We apply this framework to evaluate the offline version of the MPI-Earth system model's land surface scheme JSBACH. We demonstrate that the complementary use of atmospheric CO2 and satellite based vegetation activity data allows to pinpoint specific model failures that would not be possible by the sole use of atmospheric CO2 observations.

scholarly journals Entropy production and multiple equilibria: the case of the ice-albedo feedback

2011 ◽  
Vol 2 (1) ◽  
pp. 13-23 ◽  
Author(s):  
C. Herbert ◽  
D. Paillard ◽  
B. Dubrulle
Keyword(s):  
Entropy Production ◽  
Multiple Equilibria ◽  
Complex Dynamics ◽  
Surface Heat ◽  
Earth System ◽  
Unstable Solution ◽  
Solar Constant ◽  
The Earth ◽  
Classical Dynamical System ◽  
The Stability

Abstract. Nonlinear feedbacks in the Earth System provide mechanisms that can prove very useful in understanding complex dynamics with relatively simple concepts. For example, the temperature and the ice cover of the planet are linked in a positive feedback which gives birth to multiple equilibria for some values of the solar constant: fully ice-covered Earth, ice-free Earth and an intermediate unstable solution. In this study, we show an analogy between a classical dynamical system approach to this problem and a Maximum Entropy Production (MEP) principle view, and we suggest a glimpse on how to reconcile MEP with the time evolution of a variable. It enables us in particular to resolve the question of the stability of the entropy production maxima. We also compare the surface heat flux obtained with MEP and with the bulk-aerodynamic formula.

SYSTEMLINK - a new project on the effects of stressors across ecosystem barriers

2020 ◽  
Author(s):  
Johanna Girardi ◽  
Ralf Schulz ◽  
Mirco Bundschuh ◽  
Martin H. Entling ◽  
Eva Kröner ◽  
...  
Keyword(s):  
Aquatic Ecosystems ◽  
Multiple Stressors ◽  
Research Training ◽  
Terrestrial Ecosystems ◽  
Water Source ◽  
Training Group ◽  
Landscape Scale ◽  
Top Down ◽  
Bottom Up ◽  
Riparian Plants

&lt;p&gt;The propagation of environmental stressors from water (source) to land (sink) in aquatic-terrestrial meta-ecosystems, has not been intensively investigated. The other way around has been in the focus of linking terrestrial and aquatic domains. To start bridging that gap, SYSTEMLINK, a DFG Research Training Group, addresses the bottom-up and top-down mediated interactions in terrestrial ecosystems, which origin from anthropogenic impairments on aquatic ecosystems. Micropollutants (fungicides and insecticides) as well as invasive species (riparian plants and invertebrates) are considered as crucial forms of multiple stressors in disturbed aquatic ecosystems. SYSTEMLINK will examine the general hypotheses that 1) invasive invertebrates and insecticide exposure and 2) invasive riparian plants and fungicide exposure cause top-down and bottom-up mediated responses in terrestrial ecosystems, respectively. Collaborative experiments in replicated outdoor aquatic-terrestrial mesocosms (site-scale) amended by joint pot experiments (batch-scale), field studies (landscape-scale), and modelling are used to test these general and several more specific hypotheses. The experimental setups will all represent a multi-stress environment and will be derived from the landscape scale. The regular combination of several scales will allow to overcome scale-specific limitations and to ensure both cause-effect quantification and the environmental relevance of the results. Ultimately, SYSTEMLINK thrives to increase our knowledge on effect translation across ecosystem boundaries. By combining biological subsidies and biogeochemical fluxes we will be able to quantify their relative importance. Furthermore, we will closely incorporate the often separated aquatic and terrestrial research areas.&lt;/p&gt;

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