scholarly journals Competing roles of rising CO<sub>2</sub> and climate change in the contemporary European carbon balance

2007 ◽  
Vol 4 (4) ◽  
pp. 2385-2405 ◽  
Author(s):  
R. Harrison ◽  
C. Jones
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Carbon Balance ◽  
Atmospheric Co2 ◽  
Natural Ecosystems ◽  
Climate Effect ◽  
Carbon Cycle Model ◽  
Land Use And Management ◽  
The Impact ◽  
And Storage

Abstract. Natural ecosystems respond to, and may affect climate change through uptake and storage of atmospheric CO2. Here we use the land-surface and carbon cycle model JULES to simulate the contemporary European carbon balance and its sensitivity to rising CO2 and changes in climate. We find that the impact of climate change is to decrease the ability of Europe to store carbon by about 175 TgC yr−1. In contrast, the effect of rising atmospheric CO2 has been to stimulate increased uptake and storage. The CO2 effect is currently dominant leading to a net increase of around 150 TgC yr−1. Our simulations do not at present include other important factors such as land use and management, the effects of forest age classes and nitrogen deposition. There seems to be an emerging consensus that changes in climate will weaken the European land-surface's ability to take up and store carbon. It is likely that this effect is happening at the present and will continue even more strongly in the future as climate continues to change. Although CO2 enhanced growth currently exceeds the climate effect, this may not continue indefinitely. Understanding this balance and its implications for mitigation policies is becoming increasingly important.

scholarly journals Competing roles of rising CO<sub>2</sub> and climate change in the contemporary European carbon balance

2008 ◽  
Vol 5 (1) ◽  
pp. 1-10 ◽  
Author(s):  
R. G. Harrison ◽  
C. D. Jones ◽  
J. K. Hughes
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Carbon Balance ◽  
Atmospheric Co2 ◽  
Natural Ecosystems ◽  
Age Classes ◽  
Carbon Cycle Model ◽  
Land Use And Management ◽  
The Impact ◽  
And Storage

Abstract. Natural ecosystems respond to, and may affect climate change through uptake and storage of atmospheric CO2. Here we use the land-surface and carbon cycle model JULES to simulate the contemporary European carbon balance and its sensitivity to rising CO2 and changes in climate. We find that the impact of climate change is to decrease the ability of Europe to store carbon by 97 TgC yr−1. In contrast, the effect of rising atmospheric CO2 has been to stimulate increased uptake and storage. The CO2 effect is currently dominant leading to a net increase of 114 TgC yr−1. Our simulations do not at present include other important factors such as land use and management, the effects of forest age classes and nitrogen deposition. Understanding this balance and its implications for mitigation policies is becoming increasingly important.

scholarly journals Regional variability of acidification in the Arctic: a sea of contrasts

2014 ◽  
Vol 11 (2) ◽  
pp. 293-308 ◽  
Author(s):  
E. E. Popova ◽  
A. Yool ◽  
Y. Aksenov ◽  
A. C. Coward ◽  
T. R. Anderson
Keyword(s):  
Climate Change ◽  
Primary Production ◽  
Arctic Ocean ◽  
Canadian Arctic ◽  
Atmospheric Co2 ◽  
The Arctic ◽  
Canadian Arctic Archipelago ◽  
Regional Variability ◽  
The Arctic Ocean ◽  
The Impact

Abstract. The Arctic Ocean is a region that is particularly vulnerable to the impact of ocean acidification driven by rising atmospheric CO2, with potentially negative consequences for calcifying organisms such as coccolithophorids and foraminiferans. In this study, we use an ocean-only general circulation model, with embedded biogeochemistry and a comprehensive description of the ocean carbon cycle, to study the response of pH and saturation states of calcite and aragonite to rising atmospheric pCO2 and changing climate in the Arctic Ocean. Particular attention is paid to the strong regional variability within the Arctic, and, for comparison, simulation results are contrasted with those for the global ocean. Simulations were run to year 2099 using the RCP8.5 (an Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) scenario with the highest concentrations of atmospheric CO2). The separate impacts of the direct increase in atmospheric CO2 and indirect effects via impact of climate change (changing temperature, stratification, primary production and freshwater fluxes) were examined by undertaking two simulations, one with the full system and the other in which atmospheric CO2 was prevented from increasing beyond its preindustrial level (year 1860). Results indicate that the impact of climate change, and spatial heterogeneity thereof, plays a strong role in the declines in pH and carbonate saturation (Ω) seen in the Arctic. The central Arctic, Canadian Arctic Archipelago and Baffin Bay show greatest rates of acidification and Ω decline as a result of melting sea ice. In contrast, areas affected by Atlantic inflow including the Greenland Sea and outer shelves of the Barents, Kara and Laptev seas, had minimal decreases in pH and Ω because diminishing ice cover led to greater vertical mixing and primary production. As a consequence, the projected onset of undersaturation in respect to aragonite is highly variable regionally within the Arctic, occurring during the decade of 2000–2010 in the Siberian shelves and Canadian Arctic Archipelago, but as late as the 2080s in the Barents and Norwegian seas. We conclude that, for future projections of acidification and carbonate saturation state in the Arctic, regional variability is significant and needs to be adequately resolved, with particular emphasis on reliable projections of the rates of retreat of the sea ice, which are a major source of uncertainty.

scholarly journals Plant Phenology and Its Anthropogenic and Natural Influencing Factors in Densely Populated Areas During the Economic Transition Period of China

2022 ◽  
Vol 9 ◽  
Author(s):  
Peijun Ju ◽  
Wenchao Yan ◽  
Jianliang Liu ◽  
Xinwei Liu ◽  
Liangfeng Liu ◽  
...  
Keyword(s):  
Climate Change ◽  
Economic Transition ◽  
Transition Period ◽  
Growing Season ◽  
Plant Phenology ◽  
Future Research ◽  
Urban Management ◽  
Climate Factors ◽  
Natural Ecosystems ◽  
The Impact

As a sensitive, observable, and comprehensive indicator of climate change, plant phenology has become a vital topic of global change. Studies about plant phenology and its responses to climate change in natural ecosystems have drawn attention to the effects of human activities on phenology in/around urban regions. The key factors and mechanisms of phenological and human factors in the process of urbanization are still unclear. In this study, we analyzed variations in xylophyta phenology in densely populated cities during the fast urbanization period of China (from 1963 to 1988). We assessed the length of the growing season affected by the temperature and precipitation. Temperature increased the length of the growing season in most regions, while precipitation had the opposite effect. Moreover, the plant-growing season is more sensitive to preseason climate factors than to annual average climate factors. The increased population reduced the length of the growing season, while the growing GDP increased the length of the growing season in most regions (8 out of 13). By analyzing the impact of the industry ratio, we found that the correlation between the urban management of emerging cities (e.g., Chongqing, Zhejiang, and Guizhou) and the growing season is more significant, and the impact is substantial. In contrast, urban management in most areas with vigorously developed heavy industry (e.g., Heilongjiang, Liaoning, and Beijing) has a weak and insignificant effect on plant phenology. These results indicate that different urban development patterns can influence urban plant phenology. Our results provide some support and new thoughts for future research on urban plant phenology.

Open areas in patchy ecosystems: key spaces for vegetation survival.

2021 ◽  
Author(s):  
Borja Rodríguez Lozano ◽  
Emilio Rodriguez-Caballero ◽  
Yolanda Cantón
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Vegetation Coverage ◽  
Runoff Water ◽  
Water Losses ◽  
Vegetation Productivity ◽  
Aridity Gradient ◽  
Water Redistribution ◽  
The Impact ◽  
Vegetation Patches

&lt;p&gt;Drylands are one of the largest biomes over the Earth, covering around 40% of land surface. These are water limited ecosystems where vegetation occupies the most favourable positions over the landscape. Less favourable areas are frequently covered by other biotic and abiotic components such as biological soil crusts, bare soil, or stones. During most rainfall events, runoff is generated in open areas (runoff sources) and redistributed through vegetation patches (runoff sinks), therefore increasing water and nutrient availability for plants. Water redistribution feedbacks determine vegetation coverage and productivity, modulate changes in its spatial distribution, and could ameliorate the predicted negative effects of climate change over these ecosystems.&lt;/p&gt;&lt;p&gt;The principal aim of this study was to quantify the impact of water redistribution processes on vegetation performance, and to evaluate how this effect varies in response to aridity. To achieve it, we analysed the relationships between runoff redistribution from open areas and vegetation productivity, by combining satellite information on vegetation state and topography. More precisely, we calculated Normalized Difference Vegetation Index (NDVI) dynamics during three hydrological years in 17 study sites along an aridity gradient in the SE of the Iberian Peninsula using SENTINEL 2 images. Then we used a DEM and a high spatial resolution vegetation map to derive a water redistribution index that simulate source-sinks interactions between vegetation and open areas. Finally, we analyse the relationship between, potential water redistribution and vegetation dynamics and how it varies along the aridity gradient.&lt;/p&gt;&lt;p&gt;We found a non-linear relationship between potential water redistribution and vegetation productivity. Overall, vegetation NDVI increases as potential water redistribution did, which demonstrated the importance of water redistribution processes on drylands vegetation performance. However, vegetation capacity to retain runoff water is limited and there is a clear threshold above which increased potential water redistribution does not promote vegetation productivity. Thresholds are caused by the limit capacity of vegetation to infiltrate run off when preferential flows are forming, increasing ecosystem connectivity, and involving local water losses for vegetation.&amp;#160; Therefore, an increase in open areas between vegetation patches could have a positive effect over vegetation through hydrological connectivity but until to a certain point in which global connectivity supposed water losses for plants. This process could have important effects under climate change, by controlling the resistance and resilience of vegetation in drylands ecosystems.&lt;/p&gt;&lt;p&gt;Acknowledgements. This research was supported by the FPU predoctoral fellowship from the Educational, Culture and Sports Ministry of Spain (FPU17/01886) REBIOARID (RTI2018-101921-B-I00) projects, funded by the FEDER/Science and Innovation Ministry-National Research Agency, and the RH2O-ARID (P18-RT-5130) funded by Junta de Andaluc&amp;#237;a and the European Union for Regional Development.&lt;/p&gt;

A simple approach to mimic the effect of active vegetation in hydrological models to better estimate hydrological variables under climate change

2021 ◽  
Author(s):  
Thedini Asali Peiris ◽  
Petra Döll
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Climate Models ◽  
Potential Evapotranspiration ◽  
Global Climate ◽  
Global Climate Models ◽  
Hydrological Models ◽  
Net Radiation ◽  
Ensemble Mean ◽  
The Impact

&lt;p&gt;Unlike global climate models, hydrological models cannot simulate the feedbacks among atmospheric processes, vegetation, water, and energy exchange at the land surface. This severely limits their ability to quantify the impact of climate change and the concurrent increase of atmospheric CO&lt;sub&gt;2&lt;/sub&gt; concentrations on evapotranspiration and thus runoff. Hydrological models generally calculate actual evapotranspiration as a fraction of potential evapotranspiration (PET), which is computed as a function of temperature and net radiation and sometimes of humidity and wind speed. Almost no hydrological model takes into account that PET changes because the vegetation responds to changing CO&lt;sub&gt;2&lt;/sub&gt; and climate. This active vegetation response consists of three components. With higher CO&lt;sub&gt;2&lt;/sub&gt; concentrations, 1) plant stomata close, reducing transpiration (physiological effect) and 2) plants may grow better, with more leaves, increasing transpiration (structural effect), while 3) climatic changes lead to changes in plants growth and even biome shifts, changing evapotranspiration. Global climate models, which include dynamic vegetation models, simulate all these processes, albeit with a high uncertainty, and take into account the feedbacks to the atmosphere.&lt;/p&gt;&lt;p&gt;Milly and Dunne (2016) (MD) found that in the case of RCP8.5 the change of PET (computed using the Penman-Monteith equation) between 1981- 2000 and 2081-2100 is much higher than the change of non-water-stressed evapotranspiration (NWSET) computed by an ensemble of global climate models. This overestimation is partially due to the neglect of active vegetation response and partially due to the neglected feedbacks between the atmosphere and the land surface.&lt;/p&gt;&lt;p&gt;The objective of this paper is to present a simple approach for hydrological models that enables them to mimic the effect of active vegetation on potential evapotranspiration under climate change, thus improving computation of freshwater-related climate change hazards by hydrological models. MD proposed an alternative approach to estimate changes in PET for impact studies that is only a function of the changes in energy and not of temperature and achieves a good fit to the ensemble mean change of evapotranspiration computed by the ensemble of global climate models in months and grid cells without water stress. We developed an implementation of the MD idea for hydrological models using the Priestley-Taylor equation (PET-PT) to estimate PET as a function of net radiation and temperature. With PET-PT, an increasing temperature trend leads to strong increases in PET. Our proposed methodology (PET-MD) helps to remove this effect, retaining the impact of temperature on PET but not on long-term PET change.&lt;/p&gt;&lt;p&gt;We implemented the PET-MD approach in the global hydrological model WaterGAP2.2d. and computed daily time series of PET between 1981 and 2099 using bias-adjusted climate data of four global climate models for RCP 8.5. We evaluated, computed PET-PT and PET-MD at the grid cell level and globally, comparing also to the results of the Milly-Dunne study. The global analysis suggests that the application of PET-MD reduces the PET change until the end of this century from 3.341 mm/day according to PET-PT to 3.087 mm/day (ensemble mean over the four global climate models).&lt;/p&gt;&lt;p&gt;Milly, P.C.D., Dunne K.A. (2016). DOI:10.1038/nclimate3046.&lt;/p&gt;

Climate Conditions and Biodiversity Decline

2022 ◽  
pp. 748-763
Author(s):  
Ashok K. Rathoure ◽  
Unnati Rajendrakumar Patel
Keyword(s):  
Climate Change ◽  
Climatic Change ◽  
Biological Diversity ◽  
Convention On Biological Diversity ◽  
Natural Ecosystems ◽  
Climate Conditions ◽  
Impact Of Climate Change ◽  
Fragile Environment ◽  
Impact On Biodiversity ◽  
The Impact

Many studies in recent years have investigated the effects of climate change on the future of biodiversity. In this chapter, the authors first examined the different possible effects of climate change that can operate at individual, population, species, community, ecosystem, notably showing that species can respond to climate challenges by shifting their climatic change. Climate change is one of the most important global environmental challenges that affect all the natural ecosystems of the world. Due to the fragile environment, mountain ecosystems are the most vulnerable to the impact of climate change. Climatic change will affect vegetation, humans, animals, and ecosystem that will impact on biodiversity. Mountains have been recognized as important ecosystems by the Convention on Biological Diversity. Climate change will not only threaten the biodiversity, but also affect the socio-economic condition of the indigenous people of the state. Various activities like habitat loss, deforestation, and exploitation amplify the impact of climate change on biodiversity.

scholarly journals A strategy for seed management with climate change

2009 ◽  
Vol 85 (1) ◽  
pp. 39-42 ◽  
Author(s):  
B.S.P. Wang ◽  
E K Morgenstern
Keyword(s):  
Climate Change ◽  
Management Strategy ◽  
Seed Source ◽  
Seedling Production ◽  
Key Words Adaptation ◽  
Physiological Quality ◽  
Seed Management ◽  
Species Adaptability ◽  
The Impact ◽  
And Storage

While climate change has been generally accepted by the forestry community, we are still searching for ways and means to alleviate its impact. We still have to collect seeds, for example, to support continued reforestation programs. To provide some guidance for meeting the changing environments, we felt it is important to review the current seed management strategy, discuss species adaptability and seed source as well as collection, handling, germination, treatment and storage. Further, we give recommendations to minimize the impact of climate change. Key words: adaptation, seed source, collection, handling, storage, dormancy treatment, germination, genetic and physiological quality, seedling production

scholarly journals Spatio-Temporal Variations of Carbon Use Efficiency in Natural Terrestrial Ecosystems and the Relationship with Climatic Factors in the Songnen Plain, China

2019 ◽  
Vol 11 (21) ◽  
pp. 2513 ◽  
Author(s):  
Bo Li ◽  
Fang Huang ◽  
Lijie Qin ◽  
Hang Qi ◽  
Ning Sun
Keyword(s):  
Primary Productivity ◽  
Land Surface ◽  
Climatic Factors ◽  
Transitional Region ◽  
Songnen Plain ◽  
Natural Ecosystems ◽  
Land Surface Phenology ◽  
Carbon Use Efficiency ◽  
Use Efficiency ◽  
The Impact

The Songnen Plain (SNP) is an important grain production base, and is designated as an ecological red-line as a protected area in China. Natural ecosystems such as the ecological protection barrier play an important role in maintaining the productivity and sustainability of farmland. Carbon use efficiency (CUE), defined as the ratio of net primary productivity (NPP) to gross primary productivity (GPP), represents the ecosystem capacity of transferring carbon from the atmosphere to terrestrial biomass. The understanding of the CUE of natural ecosystems in protected farmland areas is vital to predicting the impact of global change and human disturbances on carbon budgets and evaluating ecosystem functions. To date, the changes in CUE at different time scales and their relationships with climatic factors have yet to be fully understood. CUE and the response to land surface phenology are also deserving attention. In this study, variations in ecosystem CUE in the SNP during 2001–2015 were investigated using Moderate-Resolution Imaging Spectroradiometer (MODIS) GPP and NPP data products estimated using the Carnegie-Ames-Stanford approach (CASA) model. The relationships between CUE and phenological and climate factors were explored. The results showed that ecosystem CUE fluctuated over time in the SNP. The lowest and highest CUE values mainly occurred in May and October, respectively. At seasonal scale, average CUE followed a descending order of Autumn > Summer > Spring. The CUE of mixed forest was greater than that of other ecosystems at both monthly and seasonal scales. Land surface phenology plays an important role in the regulation of CUE. The earlier start (SOS), the later end (EOS) and longer length (LOS) of the growing season would contribute increasing of CUE. Precipitation and temperature affected CUE positively in most areas of the SNP. These findings help explain the CUE of natural ecosystems in the protected farmland areas and improve our understanding of ecosystem carbon allocation dynamics in temperate semi-humid to semi-arid transitional region under climate and phenological fluctuations.

scholarly journals Baseline-Dependent Responses of Soil Organic Carbon Dynamics to Climate and Land Disturbances

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Zhengxi Tan ◽  
Shuguang Liu
Keyword(s):  
Land Use ◽  
Land Surface ◽  
Management Practices ◽  
C Sequestration ◽  
The United States ◽  
Natural Ecosystems ◽  
Organic C ◽  
Realistic Option ◽  
Managed Ecosystems ◽  
Land Use And Management

Terrestrial carbon (C) sequestration through optimizing land use and management is widely considered a realistic option to mitigate the global greenhouse effect. But how the responses of individual ecosystems to changes in land use and management are related to baseline soil organic C (SOC) levels still needs to be evaluated at various scales. In this study, we modeled SOC dynamics within both natural and managed ecosystems in North Dakota of the United States and found that the average SOC stock in the top 20 cm depth of soil lost at a rate of 450 kg C ha−1 yr−1in cropland and 110 kg C ha−1 yr−1in grassland between 1971 and 1998. Since 1998, the study area had become a SOC sink at a rate of 44 kg C ha−1 yr−1. The annual rate of SOC change in all types of lands substantially depends on the magnitude of initial SOC contents, but such dependency varies more with climatic variables within natural ecosystems and with management practices within managed ecosystems. Additionally, soils with high baseline SOC stocks tend to be C sources following any land surface disturbances, whereas soils having low baseline C contents likely become C sinks following conservation management.

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