scholarly journals Amplified warming induced by large-scale application of water-saving techniques

2022 ◽  
Author(s):  
Jing Fu ◽  
Shaozhong Kang ◽  
Lu Zhang ◽  
Xiaolin Li ◽  
Pierre Gentine ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Large Scale ◽  
Global Climate ◽  
Substantial Reduction ◽  
Water Saving ◽  
Irrigated Agriculture ◽  
Near Surface ◽  
Irrigation Water Use ◽  
The Impact

Abstract Large-scale agricultural activities can exacerbate global climate change. In the past three decades, over 5 Mha of cultivated land have been equipped with Water-Saving Techniques (WST) in Northwest China to cope with water scarcity. However, the effect of WST on local climate and its mechanisms are not yet understood. Here we quantified the local climatic effect by comparing temperature and humidity at controlled and irrigated sites before and after the large-scale implementation of WST. Results show that the substantial reduction in irrigation water use has led to an average increase of 0.3°C in growing-season temperature and reduced relative humidity by 2%. Near-surface air temperature responds nonlinearly to percentage area of WST and a threshold value of 40% is found before any noticeable warming effect over the study area. Moreover, it is found that regions with relatively humid climates respond more significantly to WST. This study reveals the mechanism of WST on near-surface climate and highlights the importance of incorporating this feedback into sustainable water management and land-surface models for assessing the impact of irrigated agriculture on regional climate change.

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

<p>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<sub>2</sub> 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<sub>2</sub> and climate. This active vegetation response consists of three components. With higher CO<sub>2</sub> 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.</p><p>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.</p><p>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.</p><p>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).</p><p>Milly, P.C.D., Dunne K.A. (2016). DOI:10.1038/nclimate3046.</p>

scholarly journals The impact of Climate Change on the Western Pacific Subtropical High and the related ozone pollution in Shanghai, China

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Luyu Chang ◽  
Jianming Xu ◽  
Xuexi Tie ◽  
Wei Gao
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Transport Model ◽  
Global Climate ◽  
Photochemical Reactions ◽  
Ozone Pollution ◽  
High Positive Correlation ◽  
Near Surface ◽  
High Solar Radiation ◽  
The Impact

AbstractSevere ozone (O3) episodes occur frequently in Shanghai during late-summers. We define geopotential height averaged over the key area region (122.5°E-135°E, 27.5°N -35°N) at 500 hPa as a WPSH_SHO3 index which has high positive correlation with surface O3 concentration in Shanghai. In addition, the index has a significant long-term increasing trend during the recent 60 years. Analysis shows the meteorological conditions under the strong WPSH_SHO3 climate background (compared to the weak background) have several important anomalies: (1) A strong WPSH center occurs over the key area region. (2) The cloud cover is less, resulting in high solar radiation and low humidity, enhancing the photochemical reactions of O3. (3) The near-surface southwesterly winds are more frequent, enhancing the transport of upwind pollutants and O3 precursors from polluted regions to Shanghai and producing higher O3 chemical productions. This study suggests that the global climate change could lead to a stronger WPSH in the key region, enhancing ozone pollution in Shanghai. A global chemical/transport model (MOZART-4) is applied to show that the O3 concentrations can be 30 ppbv higher under a strong WPSH_SHO3 condition than a weak condition, indicating the important effect of the global climate change on local air pollution in Shanghai.

Constraining the model representation of the aerosol life cycle in relation to sources and sinks.

2020 ◽  
Author(s):  
Paul Kim ◽  
Daniel Partridge ◽  
James Haywood
Keyword(s):  
Climate Change ◽  
Life Cycle ◽  
Large Scale ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Evaluation Framework ◽  
Microphysical Properties ◽  
The Impact ◽  
Source And Sink

<p>Global climate model (GCM) ensembles still produce a significant spread of estimates for the future of climate change which hinders our ability to influence policymakers. The range of these estimates can only partly be explained by structural differences and varying choice of parameterisation schemes between GCMs. GCM representation of cloud and aerosol processes, more specifically aerosol microphysical properties, remain a key source of uncertainty contributing to the wide spread of climate change estimates. The radiative effect of aerosol is directly linked to the microphysical properties and these are in turn controlled by aerosol source and sink processes during transport as well as meteorological conditions.</p><p>A Lagrangian, trajectory-based GCM evaluation framework, using spatially and temporally collocated aerosol diagnostics, has been applied to over a dozen GCMs via the AeroCom initiative. This framework is designed to isolate the source and sink processes that occur during the aerosol life cycle in order to improve the understanding of the impact of these processes on the simulated aerosol burden. Measurement station observations linked to reanalysis trajectories are then used to evaluate each GCM with respect to a quasi-observational standard to assess GCM skill. The AeroCom trajectory experiment specifies strict guidelines for modelling groups; all simulations have wind fields nudged to ERA-Interim reanalysis and all simulations use emissions from the same inventories. This ensures that the discrepancies between GCM parameterisations are emphasised and differences due to large scale transport patterns, emissions and other external factors are minimised.</p><p>Preliminary results from the AeroCom trajectory experiment will be presented and discussed, some of which are summarised now. A comparison of GCM aerosol particle number size distributions against observations made by measurement stations in different environments will be shown, highlighting the difficulties that GCMs have at reproducing observed aerosol concentrations across all size ranges in pristine environments. The impact of precipitation during transport on aerosol microphysical properties in each GCM will be shown and the implications this has on resulting aerosol forcing estimates will be discussed. Results demonstrating the trajectory collocation framework will highlight its ability to give more accurate estimates of the key aerosol sources in GCMs and the importance of these sources in influencing modelled aerosol-cloud effects. In summary, it will be shown that this analysis approach enables us to better understand the drivers behind inter-model and model-observation discrepancies.</p>

'Paris rules' will drive global climate progress

2016 ◽  
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Global Climate ◽  
National Level ◽  
Implementation Process ◽  
Peer Pressure ◽  
Content Type ◽  
Climate Change Effects ◽  
Growth Prospects ◽  
The Impact

Significance COP22 has been dubbed "the COP of action, adaptation and Africa". It is a key opportunity to build confidence in the system of global cooperation adopted at the Paris Climate Conference. The Paris meeting ushered in a new framework for cooperation on climate change based on voluntary emissions reductions targets that will be jointly reviewed every five years. Negotiators gathering in Marrakech for COP22 face the task of making the Paris Agreement work -- and delivering results on a sufficiently large scale. Impacts Cooperation under the Paris framework will help reduce climate change effects, though overshooting of the 2 degree target is inevitable. The Paris deal's reliance on peer pressure and self-policing will risk national-level backsliding during the implementation process. Actions taken in the next ten years will determine the impact of climate change on global growth prospects for the whole of this century.

Assessing the effects of climate change on US West Coast sablefish productivity and on the performance of alternative management strategies

2019 ◽  
Vol 76 (6) ◽  
pp. 1524-1542
Author(s):  
Melissa A Haltuch ◽  
Z Teresa A’mar ◽  
Nicholas A Bond ◽  
Juan L Valero
Keyword(s):  
Climate Change ◽  
West Coast ◽  
Large Scale ◽  
Climate Models ◽  
Global Climate ◽  
Management Strategies ◽  
Climate Impacts ◽  
Global Climate Models ◽  
The Impact ◽  
Us West

Abstract US West Coast sablefish are economically valuable, with landings of 11.8 million pounds valued at over $31 million during 2016, making assessing and understanding the impact of climate change on the California Current (CC) stock a priority for (1) forecasting future stock productivity, and (2) testing the robustness of management strategies to climate impacts. Sablefish recruitment is related to large-scale climate forcing indexed by regionally correlated sea level (SL) and zooplankton communities that pelagic young-of-the-year sablefish feed upon. This study forecasts trends in future sablefish productivity using SL from Global Climate Models (GCMs) and explores the robustness of harvest control rules (HCRs) to climate driven changes in recruitment using management strategy evaluation (MSE). Future sablefish recruitment is likely to be similar to historical recruitment but may be less variable. Most GCMs suggest that decadal SL trends result in recruitments persisting at lower levels through about 2040 followed by higher levels that are more favorable for sablefish recruitment through 2060. Although this MSE suggests that spawning biomass and catches will decline, and then stabilize, into the future under both HCRs, the sablefish stock does not fall below the stock size that leads to fishery closures.

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 BAYWRF: a high-resolution present-day climatological atmospheric dataset for Bavaria

2020 ◽  
Vol 12 (4) ◽  
pp. 3097-3112
Author(s):  
Emily Collier ◽  
Thomas Mölg
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Large Scale ◽  
Wrf Model ◽  
Atmospheric Model ◽  
Climate Impact ◽  
Reanalysis Data ◽  
Near Surface ◽  
Local Climate ◽  
The Impact

Abstract. Climate impact assessments require information about climate change at regional and ideally also local scales. In dendroecological studies, this information has traditionally been obtained using statistical methods, which preclude the linkage of local climate changes to large-scale drivers in a process-based way. As part of recent efforts to investigate the impact of climate change on forest ecosystems in Bavaria, Germany, we developed a high-resolution atmospheric modelling dataset, BAYWRF, for this region over the thirty-year period of September 1987 to August 2018. The atmospheric model employed in this study, the Weather Research and Forecasting (WRF) model, was configured with two nested domains of 7.5 and 1.5 km grid spacing centred over Bavaria and forced at the outer lateral boundaries by ERA5 reanalysis data. Using an extensive network of observational data, we evaluate (i) the impact of using grid analysis nudging for a single-year simulation of the period of September 2017 to August 2018 and (ii) the full BAYWRF dataset generated using nudging. The evaluation shows that the model represents variability in near-surface meteorological conditions generally well, although there are both seasonal and spatial biases in the dataset that interested users should take into account. BAYWRF provides a unique and valuable tool for investigating climate change in Bavaria with high interdisciplinary relevance. Data from the finest-resolution WRF domain are available for download at daily temporal resolution from a public repository at the Open Science Framework (Collier, 2020; https://doi.org/10.17605/OSF.IO/AQ58B).

scholarly journals Insurance as a risk management system in green construction

2022 ◽  
Vol 42 ◽  
pp. 06003
Author(s):  
Kheda Murtazova ◽  
Salambek Aliyev
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Global Climate ◽  
Green Building ◽  
Economic Research ◽  
Corporate Strategies ◽  
Climate Risks ◽  
Risk Management System ◽  
The Impact

The study of the problems of the impact of climate change on economic development has become in recent years one of the main directions of economic research. At the same time, along with the development of a global macroeconomic policy in the field of climate and green building, more and more attention is paid to the analysis of corporate strategies to reduce risks and adapt to the consequences of climate change. Without large-scale business investments in green innovative technologies and the introduction of corporate standards for reducing greenhouse gas emissions, it is impossible to achieve long-term targets for reducing global climate risks.

scholarly journals Mechanisms of Climate Change in the Semiarid African Sahel: The Local View

2010 ◽  
Vol 23 (3) ◽  
pp. 743-756 ◽  
Author(s):  
Alessandra Giannini
Keyword(s):  
Climate Change ◽  
Land Surface ◽  
Southern Oscillation ◽  
Net Energy ◽  
Moist Static Energy ◽  
Near Surface ◽  
Vertical Stability ◽  
First Case ◽  
Static Energy ◽  
The Impact

Abstract Application of the moist static energy framework to analyses of vertical stability and net energy in the Sahel sheds light on the divergence of projections of climate change. Two distinct mechanisms are sketched. In one, anthropogenic warming changes continental climate indirectly: warming of the oceans increases moist static energy at upper levels, affecting vertical stability globally, from the top down, and driving drying over the Sahel, in a way analogous to the impact of El Niño–Southern Oscillation on the global tropical atmosphere. In the other, the increase in anthropogenic greenhouse gases drives a direct continental change: the increase in net terrestrial radiation at the surface increases evaporation, favoring vertical instability and near-surface convergence from the bottom up. In both cases the surface warms, but in the first precipitation and evaporation decrease, while in the second they increase. In the first case, land surface warming is brought about by the remotely forced decrease in precipitation and consequent decrease in evaporation and increase in net solar radiation at the surface. In the second, it is brought about by the increase in net terrestrial radiation at the surface, amplified by the water vapor feedback associated with an increase in near-surface humidity.

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