scholarly journals Modeling the response of glacier systems to climate warming in China

2006 ◽  
Vol 43 ◽  
pp. 313-316 ◽  
Author(s):  
Zi-Chu Xie ◽  
Xin Wang ◽  
Qing-Hua Feng ◽  
Er’si Kang ◽  
Chao-Hai Liu ◽  
...  
Keyword(s):  
Steady State ◽  
Climate Warming ◽  
Temperature Increase ◽  
Summer Temperature ◽  
Equilibrium Line ◽  
Glacier System ◽  
Median Size ◽  
Functional Models ◽  
Climatic Scenarios ◽  
Glacier Ablation

AbstractA glacier system is regarded as the ensemble of many glaciers sharing the same region, influenced by a similar climate and organized by certain intrinsic laws. It can be either ‘sensitive’ or ‘steady’. On the basis of the structure of the glacier system and the nature of the equilibrium-line altitudes at the steady state, functional models of a glacier system responding to climate warming were established, using the Kotlyakov–Krenke equation relating annual glacier ablation and mean summer temperature and the glacier system’s median size. The modeling results under the climatic scenarios with a rate of temperature increase of 0.01, 0.03 and 0.05 K a-1 indicate that by the end of this century the glacial area of China will be reduced by –14%, –40%and –60% respectively. However, model results show distinct differences between the sensitive glacier system and the steady glacier system.

The challenge of non-stationary feedbacks within the response of debris-covered glaciers to climate forcing

2020 ◽  
Author(s):  
Anna Wirbel ◽  
Lindsey Nicholson ◽  
Christoph Mayer ◽  
Astrid Lambrecht
Keyword(s):  
Steady State ◽  
Climate Forcing ◽  
Dynamic Component ◽  
Mountain Ranges ◽  
Glacier System ◽  
Ablation Regime ◽  
Debris Cover ◽  
Glacier Ablation ◽  
The Impact ◽  
Development And Evolution

<p><strong>The challenge of non-stationary feedbacks within the response of debris-covered glaciers to climate forcing</strong></p><p>Debris-covered glaciers are a feature of many mountain ranges around the world and their proportion is expected to increase under continued climate warming.</p><p>The impact of debris cover on glacier behavior, via its profound modification of the glacier ablation regime, causes debris-covered glaciers to respond to the same climate forcing in a markedly different way to clean ice glaciers. In order to better understand how debris cover impacts the glacier’s response to climate forcing, we revisit the concept of steady state and examine it for a debris-covered glacier system. We present simple modeling results to explore how the development and evolution of debris cover affects the potential for steady-state and how feedbacks instigated by supraglacial debris cover complicate the glacier’s response to a prescribed steady climate. These investigations highlight the non-stationarity induced by the presence of debris and as a result, that debris cannot be considered as a static component, as it is a highly dynamic component which affects the glacier system in different ways.</p><p><br><br></p>

scholarly journals Ecosystem carbon transit versus turnover times in response to climate warming and rising atmospheric CO<sub>2</sub> concentration

2018 ◽  
Vol 15 (21) ◽  
pp. 6559-6572 ◽  
Author(s):  
Xingjie Lu ◽  
Ying-Ping Wang ◽  
Yiqi Luo ◽  
Lifen Jiang
Keyword(s):  
Steady State ◽  
Transit Time ◽  
Climate Warming ◽  
Age Structure ◽  
C Sequestration ◽  
Turnover Time ◽  
Atmospheric Co2 ◽  
Ecosystem Carbon ◽  
Subsequent Decrease ◽  
Diagnostic Time

Abstract. Ecosystem carbon (C) transit time is a critical diagnostic parameter to characterize land C sequestration. This parameter has different variants in the literature, including a commonly used turnover time. However, we know little about how different transit time and turnover time are in representing carbon cycling through multiple compartments under a non-steady state. In this study, we estimate both C turnover time as defined by the conventional stock over flux and mean C transit time as defined by the mean age of C mass leaving the system. We incorporate them into the Community Atmosphere Biosphere Land Exchange (CABLE) model to estimate C turnover time and transit time in response to climate warming and rising atmospheric [CO2]. Modelling analysis shows that both C turnover time and transit time increase with climate warming but decrease with rising atmospheric [CO2]. Warming increases C turnover time by 2.4 years and transit time by 11.8 years in 2100 relative to that at steady state in 1901. During the same period, rising atmospheric [CO2] decreases C turnover time by 3.8 years and transit time by 5.5 years. Our analysis shows that 65 % of the increase in global mean C transit time with climate warming results from the depletion of fast-turnover C pool. The remaining 35 % increase results from accompanied changes in compartment C age structures. Similarly, the decrease in mean C transit time with rising atmospheric [CO2] results approximately equally from replenishment of C into fast-turnover C pool and subsequent decrease in compartment C age structure. Greatly different from the transit time, the turnover time, which does not account for changes in either C age structure or composition of respired C, underestimated impacts of warming and rising atmospheric [CO2] on C diagnostic time and potentially led to deviations in estimating land C sequestration in multi-compartmental ecosystems.

Variations of Temperature in Hefei City in Recent 50 Years

2012 ◽  
Vol 616-618 ◽  
pp. 1496-1499
Author(s):  
Guo Wei Xu ◽  
Xin Tian Yuan ◽  
Shu Ling Huang ◽  
Yang Gao
Keyword(s):  
Statistical Analysis ◽  
Temperature Increase ◽  
Summer Temperature ◽  
Observation Data ◽  
Annual Average ◽  
Average Temperature ◽  
Four Seasons ◽  
Temperature Observation ◽  
Significant Temperature ◽  
Annual Average Temperature

Selecting 50 years temperature observation data from1959 to 2008 and using statistical analysis, this paper revealed the characteristics of temperature variation in Hefei city. The results show that in past 50 years, the annual average temperature in Hefei city greatly increased, tendency rate of temperature change was 0.246°C/10 a, especially after 1993, the temperature increased significantly; the temperature in four seasons all increased somewhat, warming was most prominent in spring. The most significant temperature increase was in spring, winter following behind, temperature increase in autumn was not obvious, and the average summer temperature increased the most unobvious.

scholarly journals Impacts of climate warming on forests in Ontario: Options for adaptation and mitigation

2000 ◽  
Vol 76 (1) ◽  
pp. 139-149 ◽  
Author(s):  
C. S. Papadopol
Keyword(s):  
Climate Change ◽  
Climate Warming ◽  
Temperature Increase ◽  
Forest Ecosystems ◽  
Current Knowledge ◽  
Risk Environment ◽  
International Consensus ◽  
Change Models ◽  
Wide Range ◽  
Key Words Climate Change

This paper summarizes current knowledge about the optical properties of greenhouse gases and general climate-warming influences. It explains the influence of this new phenomenon on the major ecosystems of the world, and considers the process of deforestation. It then analyzes the warming trends in Ontario based on data from two weather stations with continuous records of more than 120 years, to determine the rate of warming in the Great Lakes-St. Lawrence Region. The results indicate a temperature increase of about 0.76 °C per century and an 8% increase in annual total precipitation.Current climate change models indicate that for a scenario of 2 × CO2 levels some general, probable prognoses can be made, including a temperature increase of up to 4.5 °C, which might be disastrous for existing forest ecosystems. Specifically, the consequences of climate warming on (a) northward shifts of ecological conditions, (b) forest productivity, and (c) forest physiology and health, are examined. In the context of global warming, the paper then recommends practical management measures necessary to ensure adaptation of existing forest ecosystems to the warming that is already developing. These measures are intended to provide a no-risk environment for existing forests until rotation age. Next, a wide range of mitigative measures is examined with a view to securing the long-term preservation of forest ecosystems to avoid major ecological disruptions and, gradually, to reverse climate warming. Application of these measures requires international consensus, but countries that apply these recommendations first have a chance to profit from them due to the "CO2 fertilization" effect. Key words: climate change, silviculture, forest management

scholarly journals Recent retreat of the Elbrus glacier system

2016 ◽  
Vol 62 (231) ◽  
pp. 94-102 ◽  
Author(s):  
IULIAN-HORIA HOLOBÂCĂ
Keyword(s):  
Summer Temperature ◽  
Glacier Area ◽  
Regression Analyses ◽  
Positive Relation ◽  
Glacier Surface ◽  
Glacier System ◽  
Digital Elevation ◽  
Glacier Changes ◽  
Global Land ◽  
Increasing Trend

The glacier system covering Europe's highest mountain, Elbrus, has exhibited an accelerated retreat since 1980. Some studies have related this retreat to a significant summer temperature increasing trend. Relief- and aspect-related parameters for the glacierized area have an important impact on glacier changes. In this paper, the changes in glacier area are identified, quantified and correlated with relief parameters for the period 1985–2007. Spatial analysis was performed using the GLAM-CD (Glacier Mapper – Change Detector) algorithm. The input data for this algorithm were Landsat 5 images, the Aster Global Digital Elevation and the glacier outlines from the GLIMS project (Global Land Ice Measurements from Space). Regression analyses between glacier area losses and relief-related parameters indicate a significant positive relation with the altitude and a significant negative relation with the glacier surface area. In this context, we used a correlated component regression to model these relations. The model explains >50% of the total variation.

The magnitude of temperature increase matters: how will soil organic mineralization respond to future climate warming?

2020 ◽  
Author(s):  
Jie Zhou ◽  
Yuan Wen ◽  
Lingling Shi ◽  
Michaela Dippold ◽  
Yakov Kuzyakov ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Climate Warming ◽  
Temperature Increase ◽  
Microbial Growth ◽  
N Cycling ◽  
Soil C ◽  
Soil Microbial ◽  
Soil C And N ◽  
C And N ◽  
C And N Cycling

&lt;p&gt;The Paris climate agreement is pursuing efforts to limit the increase in global temperature to below 2 &amp;#176;C above pre-industrial level. The overall consequence of relatively slight warming (~2 &amp;#176;C), on soil C and N stocks will be dependent on microorganisms decomposing organic matter through release of extracellular enzymes. Therefore, the capacity of soil microbial community to buffer climate warming in long-term and the self-regulatory mechanisms mediating soil C and N cycling through enzyme activity and microbial growth require a detailed comparative study. Here, microbial growth and the dynamics of enzyme activity (involved in C and N cycling) in response to 8 years warming (ambient, +1.6 &amp;#176;C, +3.2 &amp;#176;C) were investigated to identify shifts in soil and microbial functioning. A slight temperature increase (+1.6 &amp;#176;C) only altered microbial properties, but had no effect on either hydrolytic enzyme activity or basic soil properties. Stronger warming (+3.2 &amp;#176;C) increased the specific growth rate (&amp;#956;&lt;sub&gt;m&lt;/sub&gt;) of the microbial community, indicating an alteration in their ecological strategy, i.e. a shift towards fast-growing microorganisms and accelerated microbial turnover. Warming strongly changed microbial physiological state, as indicated by a 1.4-fold increase in the fraction of growing microorganisms (GMB) and 2 times decrease in lag-time with warming. This reduced total microbial biomass but increased specific enzyme activity to be ready to decompose increased rhizodeposition, as supported by the higher potential activitiy (V&lt;sub&gt;max&lt;/sub&gt;) and lower affinity to substrates (higher K&lt;sub&gt;m&lt;/sub&gt;) of enzymes hydrolyzing cellobiose and proteins cleavage in warmed soil. In other words, stronger warming magnitude (+3.2 &amp;#176;C) changed microbial communities, and was sufficient to benefit fast-growing microbial populations with enzyme functions that specific to degrade labile SOM. Combining with 48 literature observations, we confirmed that the slight magnitude of temperature increase (&lt; 2 &amp;#176;C) only altered microbial properties, but further temperature increases (2-4 &amp;#176;C) was sufficient to change almost all soil, microbial, and enzyme properties and related processes. As a consequence, the revealed microbial regulatory mechanism of stability of soil C storage is strongly depended on the magnitude of future climate warming.&lt;/p&gt;

scholarly journals Non-breeding waterbirds benefit from protected areas when adjusting their distribution to climate warming

2021 ◽  
Author(s):  
Elie Gaget ◽  
Diego Pavón-Jordán ◽  
Alison Johnston ◽  
Aleksi Lehikoinen ◽  
Wesley M. Hochachka ◽  
...  
Keyword(s):  
Protected Areas ◽  
Climate Warming ◽  
Species Distribution ◽  
Temperature Increase ◽  
Species Distributions ◽  
Community Change ◽  
Species Extinction ◽  
Distribution Change ◽  
Community Adjustment ◽  
Western Palearctic

AbstractClimate warming is driving changes in species distributions, although many species show a so-called climatic debt, where their range shifts lag behind the fast shift in temperature isoclines. Protected areas (PAs) may impact the rate of distribution changes both positively and negatively. At the cold edges of species distributions, PAs can facilitate species distribution changes by increasing the colonization required for distribution change. At the warm edges, PAs can mitigate the loss of species, by reducing the local extinction of vulnerable species. To assess the importance of PAs to affect species distribution change, we evaluated the changes in a non-breeding waterbird community as a response to temperature increase and PA status, using changes of species occurrence in the Western-Palearctic over 25 years (97 species, 7,071 sites, 39 countries, 1993– 2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate the species turn-over induced by temperature increase. In addition, we measured whether the thermal community adjustment was led by cold-dwelling species extinction and/or warm-dwelling species colonization, by modelling the change in standard deviation of the CTI (CTIsd). Using linear mixed-effects models, we investigated whether communities within PAs had lower climatic debt and different patterns of community change regarding the local PA surface. Thanks to the combined use of the CTI and CTIsd, we found that communities inside PAs had more species, higher colonization, lower extinction and the climatic debt was 16% lower than outside PAs. The results suggest the importance of PAs to facilitate warm-dwelling species colonization and attenuate cold-dwelling species extinction. The community adjustment was however not sufficiently fast to keep pace with the strong temperature increase in central and northeastern Western-Palearctic regions. Our study underlines the potential of the combined CTI and CTIsd metrics to understand the colonization-extinction patterns driven by climate warming.

scholarly journals Summer temperature increase has distinct effects on the ectomycorrhizal fungal communities of moist tussock and dry tundra in Arctic Alaska

2014 ◽  
Vol 21 (2) ◽  
pp. 959-972 ◽  
Author(s):  
Luis N. Morgado ◽  
Tatiana A. Semenova ◽  
Jeffrey M. Welker ◽  
Marilyn D. Walker ◽  
Erik Smets ◽  
...  
Keyword(s):  
Temperature Increase ◽  
Summer Temperature ◽  
Fungal Communities ◽  
Arctic Alaska
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