scholarly journals Projecting the release of carbon from permafrost soils using a perturbed physics ensemble

2015 ◽  
Vol 12 (23) ◽  
pp. 19499-19534
Author(s):  
A. H. MacDougall ◽  
R. Knutti
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
High Arctic ◽  
Carbon Pool ◽  
Permafrost Region ◽  
Near Surface ◽  
Permafrost Soils ◽  
Rcp 8.5 ◽  
Physics Ensemble ◽  
Perturbed Physics

Abstract. The soils of the Northern Hemisphere permafrost region are estimated to contain 1100 to 1500 Pg of carbon (Pg C). A substantial fraction of this carbon has been frozen and therefore protected from microbial decay for millennia. As anthropogenic climate warming progresses much of this permafrost is expected to thaw. Here we conduct perturbed physics experiments on a climate model of intermediate complexity, with an improved permafrost carbon module, to estimate with formal uncertainty bounds the release of carbon from permafrost soils by year 2100 and 2300. We estimate that by 2100 the permafrost region may release between 56 (13 to 118) Pg C under Representative Concentration Pathway (RCP) 2.6 and 102 (27 to 199) Pg C under RCP 8.5, with substantially more to be released under each scenario by year 2300. A subset of 25 model variants were projected 8000 years into the future under continued RCP 4.5 and 8.5 forcing. Under the high forcing scenario the permafrost carbon pool decays away over several thousand years. Under the moderate scenario forcing a remnant near-surface permafrost region persists in the high Arctic which develops a large permafrost carbon pool, leading to global recovery of the pool beginning in mid third millennium of the common era (CE). Overall our simulations suggest that the permafrost carbon cycle feedback to climate change will make a significant but not cataclysmic contribution to climate change over the next centuries and millennia.

scholarly journals Projecting the release of carbon from permafrost soils using a perturbed parameter ensemble modelling approach

2016 ◽  
Vol 13 (7) ◽  
pp. 2123-2136 ◽  
Author(s):  
Andrew H. MacDougall ◽  
Reto Knutti
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
High Arctic ◽  
Carbon Pool ◽  
Permafrost Region ◽  
Near Surface ◽  
Permafrost Soils ◽  
Rcp 8.5 ◽  
Two Parameters ◽  
Perturbed Model

Abstract. The soils of the northern hemispheric permafrost region are estimated to contain 1100 to 1500 Pg of carbon. A substantial fraction of this carbon has been frozen and therefore protected from microbial decay for millennia. As anthropogenic climate warming progresses much of this permafrost is expected to thaw. Here we conduct perturbed model experiments on a climate model of intermediate complexity, with an improved permafrost carbon module, to estimate with formal uncertainty bounds the release of carbon from permafrost soils by the year 2100 and 2300 CE. We estimate that by year 2100 the permafrost region may release between 56 (13 to 118) Pg C under Representative Concentration Pathway (RCP) 2.6 and 102 (27 to 199) Pg C under RCP 8.5, with substantially more to be released under each scenario by the year 2300. Our analysis suggests that the two parameters that contribute most to the uncertainty in the release of carbon from permafrost soils are the size of the non-passive fraction of the permafrost carbon pool and the equilibrium climate sensitivity. A subset of 25 model variants are integrated 8000 years into the future under continued RCP forcing. Under the moderate RCP 4.5 forcing a remnant near-surface permafrost region persists in the high Arctic, eventually developing a new permafrost carbon pool. Overall our simulations suggest that the permafrost carbon cycle feedback to climate change will make a significant contribution to climate change over the next centuries and millennia, releasing a quantity of carbon 3 to 54 % of the cumulative anthropogenic total.

Abrupt changes across the Arctic permafrost region endanger northern development

2020 ◽  
Author(s):  
Bernardo Teufel ◽  
Laxmi Sushama
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Regional Climate ◽  
The Arctic ◽  
Convective Precipitation ◽  
Permafrost Region ◽  
Permafrost Degradation ◽  
Near Surface ◽  
Modelling Studies ◽  
Extensive Degradation

<p>Extensive degradation of near-surface permafrost is projected during the 21st century, which will have detrimental effects on northern communities, ecosystems and engineering systems. This degradation will expectedly have consequences for many processes, which most previous modelling studies suggested would occur gradually. Here, we project that soil moisture will decrease abruptly (within a few months) in response to permafrost degradation over large areas of the present-day permafrost region, based on analysis of transient climate change simulations performed using a state-of-the-art regional climate model. This regime shift is reflected in abrupt increases in summer near-surface temperature and convective precipitation, and decreases in relative humidity and surface runoff. Of particular relevance to northern systems are changes to the bearing capacity of the soil due to increased drainage, increases in the potential for intense rainfall events and increases in lightning frequency, which combined with increases in forest fuel combustibility are projected to abruptly and substantially increase the severity of wildfires, which constitute one of the greatest risks to northern ecosystems, communities and infrastructure. The fact that these changes are projected to occur abruptly further increases the challenges associated with climate change adaptation and potential retrofitting measures.</p>

scholarly journals Regional Climate Model Emulator based on Deep Learning: Concept and First Evaluation of a Novel Hybrid Downscaling Approach

2021 ◽  
Author(s):  
Antoine Doury ◽  
Samuel Somot ◽  
Sébastien Gadat ◽  
Aurélien Ribes ◽  
Lola Corre
Keyword(s):  
Climate Change ◽  
Network Architecture ◽  
Large Scale ◽  
Climate Models ◽  
Climate Model ◽  
Regional Climate ◽  
Regional Climate Models ◽  
Future Climate ◽  
Near Surface ◽  
The Way

Abstract Providing reliable information on climate change at local scale remains a challenge of first importance for impact studies and policymakers. Here, we propose a novel hybrid downscaling method combining the strengths of both empirical statistical downscaling methods and Regional Climate Models (RCMs). The aim of this tool is to enlarge the size of high-resolution RCM simulation ensembles at low cost.We build a statistical RCM-emulator by estimating the downscaling function included in the RCM. This framework allows us to learn the relationship between large-scale predictors and a local surface variable of interest over the RCM domain in present and future climate. Furthermore, the emulator relies on a neural network architecture, which grants computational efficiency. The RCM-emulator developed in this study is trained to produce daily maps of the near-surface temperature at the RCM resolution (12km). The emulator demonstrates an excellent ability to reproduce the complex spatial structure and daily variability simulated by the RCM and in particular the way the RCM refines locally the low-resolution climate patterns. Training in future climate appears to be a key feature of our emulator. Moreover, there is a huge computational benefit in running the emulator rather than the RCM, since training the emulator takes about 2 hours on GPU, and the prediction is nearly instantaneous. However, further work is needed to improve the way the RCM-emulator reproduces some of the temperature extremes, the intensity of climate change, and to extend the proposed methodology to different regions, GCMs, RCMs, and variables of interest.

History matching for exploring and reducing climate model parameter space using observations and a large perturbed physics ensemble

2013 ◽  
Vol 41 (7-8) ◽  
pp. 1703-1729 ◽  
Author(s):  
Daniel Williamson ◽  
Michael Goldstein ◽  
Lesley Allison ◽  
Adam Blaker ◽  
Peter Challenor ◽  
...  
Keyword(s):  
Parameter Space ◽  
History Matching ◽  
Climate Model ◽  
Model Parameter ◽  
Perturbed Physics Ensemble ◽  
Physics Ensemble ◽  
Perturbed Physics

Pedoclimatic comparison of three viticultural areas of Italy devoted to high-quality Aglianico and Cabernet Sauvignon production

2020 ◽  
Author(s):  
Eugenia Monaco ◽  
Roberto De Mascellis ◽  
Giuliana Barbato ◽  
Paola Mercogliano ◽  
Maurizio Buonanno ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Regional Climate ◽  
Mediterranean Area ◽  
Climatic Conditions ◽  
Cabernet Sauvignon ◽  
Climate Projections ◽  
Italian Regions ◽  
Berry Quality ◽  
Rcp 8.5

<p>In the Mediterranean area, the expected increase in temperature coupled with the decrease in rainfall, as well as the increase in the frequency of extreme events (heatwaves and drought, IPCC, 2019), will severely affect the survival of current vineyard areas. Cultivar thermal requirement and soil water availability could be not satisfied, leading to a limitation in yield and berry quality also due to constraints in the achievement of optimal grape maturity.</p><p>In this context, the understanding of how the spatial viticultural suitability will change under climate change is of primary interest in order to identify the best adaptation strategies to guarantee the resilience of current viticultural areas. Moreover, the improvement of knowledge of climate, soil, and their interaction for each specific cultivar will be fundamental because the terroir system is based on this interaction able to influence the plant status (e.g., water).</p><p>In this study, different pedo-climatic conditions (past, present, and future) in three Italian sites at different latitudes (from center to southern), were compared for two red varieties of grapevine: Aglianico (indigenous cv) and Cabernet Sauvignon (international cv).</p><p>Grapevine adaptation to future climate in each experimental farm in Campania, Molise, and Sicily Italian regions has been realized through the use of bioclimatic indexes (e.g., Amerine & Winkler for Aglianico 2110 GDD). The climatic evaluation was performed using Regional Climate Model COSMO-CLM at high-resolution (8km x 8km) climate projections RCP4.5 and RCP 8.5 (2010-2100) and Reference Climate (RC, 1971-2005).</p><p>Results have shown how climate change will affect the cultivation of Aglianico and Cabernet Sauvignon, considering both the climate and bioclimatic needs of cultivars themselves in the current viticultural areas.</p><p>Finally, coupled with the climatic evaluation, a pedological survey to characterize the soils, and the analysis of satellite images (Sentinel2 ) coupled with stemwood anatomical analysis has been performed to reconstruct the past eco-physiological behavior.</p>

scholarly journals Mid-to-late Holocene temperature evolution and atmospheric dynamics over Europe in regional model simulations

2016 ◽  
Vol 12 (8) ◽  
pp. 1645-1662 ◽  
Author(s):  
Emmanuele Russo ◽  
Ulrich Cubasch
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Late Holocene ◽  
Climate Models ◽  
Climate Model ◽  
Set Covering ◽  
Data Set ◽  
Near Surface ◽  
Past Climate ◽  
Past Climate Change

Abstract. The improvement in resolution of climate models has always been mentioned as one of the most important factors when investigating past climatic conditions, especially in order to evaluate and compare the results against proxy data. Despite this, only a few studies have tried to directly estimate the possible advantages of highly resolved simulations for the study of past climate change. Motivated by such considerations, in this paper we present a set of high-resolution simulations for different time slices of the mid-to-late Holocene performed over Europe using the state-of-the-art regional climate model COSMO-CLM. After proposing and testing a model configuration suitable for paleoclimate applications, the aforementioned mid-to-late Holocene simulations are compared against a new pollen-based climate reconstruction data set, covering almost all of Europe, with two main objectives: testing the advantages of high-resolution simulations for paleoclimatic applications, and investigating the response of temperature to variations in the seasonal cycle of insolation during the mid-to-late Holocene. With the aim of giving physically plausible interpretations of the mismatches between model and reconstructions, possible uncertainties of the pollen-based reconstructions are taken into consideration. Focusing our analysis on near-surface temperature, we can demonstrate that concrete advantages arise in the use of highly resolved data for the comparison against proxy-reconstructions and the investigation of past climate change. Additionally, our results reinforce previous findings showing that summertime temperatures during the mid-to-late Holocene were driven mainly by changes in insolation and that the model is too sensitive to such changes over Southern Europe, resulting in drier and warmer conditions. However, in winter, the model does not correctly reproduce the same amplitude of changes evident in the reconstructions, even if it captures the main pattern of the pollen data set over most of the domain for the time periods under investigation. Through the analysis of variations in atmospheric circulation we suggest that, even though the wintertime discrepancies between the two data sets in some areas are most likely due to high pollen uncertainties, in general the model seems to underestimate the changes in the amplitude of the North Atlantic Oscillation, overestimating the contribution of secondary modes of variability.

scholarly journals Impact of Climate Change on the Hydrological Regimes in Bavaria

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1599 ◽  
Author(s):  
Benjamin Poschlod ◽  
Florian Willkofer ◽  
Ralf Ludwig
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Emission Scenario ◽  
Regional Climate ◽  
Hierarchical Cluster ◽  
Reference Period ◽  
Rcp 8.5 ◽  
Monthly Discharge ◽  
Near Future ◽  
Far Future

This study assesses the change of the seasonal runoff characteristics in 98 catchments in central Europe between the reference period of 1981–2010, and in the near future (2011–2040), mid future (2041–2070) and far future (2071–2099). Therefore, a large ensemble of 50 hydrological simulations featuring the model WaSiM-ETH driven by a 50-member ensemble of the Canadian Regional Climate Model, version 5 (CRCM5) under the emission scenario Representative Concentration Pathway (RCP 8.5) is analyzed. A hierarchical cluster analysis is applied to group the runoff characteristics into six flow regime classes. In the study area, (glacio-)nival, nival (transition), nivo-pluvial and three different pluvial classes are identified. We find that the characteristics of all six regime groups are severely affected by climate change in terms of the amplitude and timing of the monthly peaks and sinks. According to our simulations, the monthly peak of nival regimes will occur earlier in the season and the relative importance of rainfall increases towards the future. Pluvial regimes will become less balanced with higher normalized monthly discharge during January to March and a strong decrease during May to October. In comparison to the reference period, 8% of catchments will shift to another regime class until 2011–2040, whereas until 2041–2070 and 2071–2099, 23% and 43% will shift to another class, respectively.

scholarly journals How Can Climate Change Affect the UNESCO Cultural Heritage Sites in Panama?

Geosciences ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 296 ◽  
Author(s):  
Chiara Ciantelli ◽  
Elisa Palazzi ◽  
Jost von Hardenberg ◽  
Carmela Vaccaro ◽  
Francesca Tittarelli ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Construction Materials ◽  
Horizontal Resolution ◽  
Damage Functions ◽  
Near Surface ◽  
Heritage Sites ◽  
The Impact

This work investigates the impact of long-term climate change on heritage sites in Latin America, focusing on two important sites in the Panamanian isthmus included in the World Heritage List: the monumental site of Panamá Viejo (16th century) and the Fortresses of Portobelo and San Lorenzo (17th to 18th centuries). First of all, in order to support the conservation and valorisation of these sites, a characterisation of the main construction materials utilized in the building masonries was performed together with an analysis of the meteoclimatic conditions in their vicinity as provided by monitoring stations recording near-surface air temperature, relative humidity, and rainfall amounts. Secondly, the same climate variables were analysed in the historical and future simulations of a state-of-the-art global climate model, EC-Earth, run at high horizontal resolution, and then used with damage functions to make projections of deterioration phenomena on the Panamanian heritage sites. In particular, we performed an evaluation of the possible surface recession, biomass accumulation, and deterioration due to salt crystallisation cycles on these sites in the future (by midcentury, 2039–2068) compared to the recent past (1979–2008), considering a future scenario of high greenhouse gas emissions.

scholarly journals Hydrological responses to climate changes in a headwater watershed

2016 ◽  
Vol 40 (6) ◽  
pp. 647-657 ◽  
Author(s):  
Lívia Alves Alvarenga ◽  
Carlos Rogério de Mello ◽  
Alberto Colombo ◽  
Luz Adriana Cuartas ◽  
Sin Chan Chou
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Global Climate Model ◽  
Resource Planning ◽  
Southeastern Brazil ◽  
Future Climate Change ◽  
Change Scenario ◽  
Hydrological Simulation ◽  
Monthly Streamflow ◽  
Rcp 8.5

ABSTRACT Climate change impacts need to be considered in water resource planning. This work aims to study of the impacts climate change on Lavrinha headwater watershed, located in the Mantiqueira Range, southeastern Brazil. The impacts from climate change (RCP 8.5 scenario) in the Lavrinha watershed runoff were analyzed based on the "Distributed Hydrology Soil Vegetation Model" (DHSVM), forced with the climate simulated for this future climate change scenario. These simulations, in turn, were generated by the Eta regional climate model coupled to Global Climate Model (GCM) HadGEM2-ES for the 2011-2040, 2041-2070 and 2071-2099 periods. The results of this study showed that the runoff is very sensitive to rising temperatures and reduced precipitation, both projected for the RCP 8.5 scenario. The hydrological simulation projected a reduction in the monthly streamflow between 20 and 77% over the twenty-first century (2011-2099), corresponding to drastic reductions in the runoff behavior and consequently in the water production capacity of the region.

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