scholarly journals High Mountains Becoming Wetter While Deserts Getting Drier in Xinjiang, China since the 1980s

Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1131
Author(s):  
Yong Zhang ◽  
Chengbang An ◽  
Luyu Liu ◽  
Yanzhen Zhang ◽  
Chao Lu ◽  
...  

Climate change has been thought to drive the accelerated expansion of global drylands. However, many studies reveal that Arid Central Asia (ACA) has been warming and wetting in recent decades, representing an anomalous response to global climate change. Given that ACA is composed of complex ecosystems and landforms, it is not clear whether or not this trend is uniform in this topographically heterogenous region. Here, we integrate the Google Earth Engine and ERA5-Land reanalysis data to study the trend of changes, since the 1980s, in temperature and precipitation in the Tianshan Mountains and the surrounding deserts, collectively referred to as the Tianshan and Desert Ecozone, which is in Northwest China. Our results show that only 20.4% of this area is becoming both warmer and wetter, which occurs mainly in the altitudes above 2800 m (Tianshan Ecozone). All three alpine ecosystems (coniferous forests, alpine meadow, and nival zone) in the Tianshan Ecozone exhibit similar warming and wetting trends, including of elevation-dependent wetting on the specific altitude range. In contrast, the low-lying oasis where human activities are mostly concentrated is undergoing warming and drying, which will face a greater threat of drought projected under three emissions scenarios (SSP1-2.6, SSP2-4.5, and SSP5-8.5). These results highlight the importance of considering the differences of climate change in different altitude gradients and different ecosystems when studying climate change in drylands.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong Zhang ◽  
Lu-yu Liu ◽  
Yi Liu ◽  
Man Zhang ◽  
Cheng-bang An

AbstractWithin the mountain altitudinal vegetation belts, the shift of forest tree lines and subalpine steppe belts to high altitudes constitutes an obvious response to global climate change. However, whether or not similar changes occur in steppe belts (low altitude) and nival belts in different areas within mountain systems remain undetermined. It is also unknown if these, responses to climate change are consistent. Here, using Landsat remote sensing images from 1989 to 2015, we obtained the spatial distribution of altitudinal vegetation belts in different periods of the Tianshan Mountains in Northwestern China. We suggest that the responses from different altitudinal vegetation belts to global climate change are different. The changes in the vegetation belts at low altitudes are spatially different. In high-altitude regions (higher than the forest belts), however, the trend of different altitudinal belts is consistent. Specifically, we focused on analyses of the impact of changes in temperature and precipitation on the nival belts, desert steppe belts, and montane steppe belts. The results demonstrated that the temperature in the study area exhibited an increasing trend, and is the main factor of altitudinal vegetation belts change in the Tianshan Mountains. In the context of a significant increase in temperature, the upper limit of the montane steppe in the eastern and central parts will shift to lower altitudes, which may limit the development of local animal husbandry. The montane steppe in the west, however, exhibits the opposite trend, which may augment the carrying capacity of pastures and promote the development of local animal husbandry. The lower limit of the nival belt will further increase in all studied areas, which may lead to an increase in surface runoff in the central and western regions.


2021 ◽  
Author(s):  
Thomas Noël ◽  
Harilaos Loukos ◽  
Dimitri Defrance

A high-resolution climate projections dataset is obtained by statistically downscaling climate projections from the CMIP6 experiment using the ERA5-Land reanalysis from the Copernicus Climate Change Service. This global dataset has a spatial resolution of 0.1°x 0.1°, comprises 5 climate models and includes two surface daily variables at monthly resolution: air temperature and precipitation. Two greenhouse gas emissions scenarios are available: one with mitigation policy (SSP126) and one without mitigation (SSP585). The downscaling method is a Quantile Mapping method (QM) called the Cumulative Distribution Function transform (CDF-t) method that was first used for wind values and is now referenced in dozens of peer-reviewed publications. The data processing includes quality control of metadata according to the climate modelling community standards and value checking for outlier detection.


Glaciers ◽  
2015 ◽  
Author(s):  
Jorge Daniel Taillant

In the preceding chapters of this book, we’ve traveled through a world of ice that was probably largely uncharted for most of us. Hopefully, we’ve learned a little bit about these fantastic frozen natural resources that play such a fundamental role in the sustainability and balance of our global ecosystem. Glaciers are melting. They are in danger because we have placed them in danger and, as such, we need to take note of and responsibility for this vulnerability, not only to protect glaciers but also to protect the very essence of our global habitat. Glaciers have been unprotected because they are obscure, removed, alien to our daily lives, located in far away places that are for the most part inhospitable to our way of life. And yet, they are a fundamental and integral part of our way of life. With modern tools like the Internet and programs like Google Earth, we can get closer to these fabulous vulnerable resources, to learn about them and work to protect them. The world is challenged today to address global climate change. If we envision a sustainable and harmonious environment in our future, we must progressively move away from fossil fuels and introduce a more balanced and sustainable mix of energy sources grounded on renewable energy. We must find solutions to generating, harnessing, transporting, and managing renewable energies, and we must progressively phase out oil and gas from our daily lives. It is possible; it just takes personal and collective conviction to set ourselves in motion to achieve this goal. Glaciers are a majestic resource, inspiring awe and wonder in a world of frozen beauty that awaits our discovery but that also alerts us to our excesses and indifference. We are losing our glaciers because we have ignored the extreme vulnerability of our planetary ecosystem, and we now must face difficult decisions about policy, consumption, and lifestyle changes that shake the foundations of our society. Global climate change for many seems intangible.


2021 ◽  
Author(s):  
John W Whale ◽  
Collin W Ahrens ◽  
David T Tissue ◽  
Paul D Rymer

With global climate change shifting and altering temperature and precipitation regimes, the ability of natural forest stands to persist in their local environments are being challenged. For many taxa, particularly among long lived tree species, the potential to respond is underpinned by genetic and trait diversity and may be limited. We sampled 326 and 366 individuals of two widely distributed and closely-related red gum Eucalyptus species (E. blakelyi and E. tereticornis) from across their entire Australian range. We identified putatively adaptive variants associated within genes of key biological processes for both species. We mapped the change of allele frequencies of two hierarchical gene ontology groups shared by both species across geography and climate and predict genomically vulnerable regions under a projected 2070 climate scenario. Regions of potential vulnerability to decline under future climate differed between species and may be applied to guide conservation and restoration strategies. Our study indicated that some populations may contain the adaptive genomic variation necessary for these species to persist through climate change, while others may benefit from the adaptive variation of those populations to enhance resilience.


Author(s):  
L. E. Nazarova

As a result of the statistical analysis of the meteorological and water balance data for Onego Lake watershed over the period 1950-2000, noticeable changes were detected. It was found that time series of annual air temperature, precipitation and evapotranspiration over 50-year period contains positive linear trends, but no change in total streamflow to the lake has so far followed. Potential changes in the regional climate and hydrological regime for the period 2000-2050 were estimated using the results of numerical modeling with the ECHAM4/OPYC3 model for two scenarios of the global climate change. The estimation of these data shows that a general tendency to increase of annual air temperature and precipitation will remain in the new climate Mean annual precipitation will increase about 30-50 mm, mean average annual air temperature for the next 50-years period will rise from 1.6 up to 2.7-3.0 °C. Our estimation shows that for both scenarios all water balance parameters, excluding river runoff, will increase.


2020 ◽  
Vol 12 (16) ◽  
pp. 2609
Author(s):  
Yaqiong Mu ◽  
Yanqiang Wei ◽  
Jinkui Wu ◽  
Yongjian Ding ◽  
Donghui Shangguan ◽  
...  

The melting of the polar ice caps is considered to be an essential factor for global sea-level rise and has received significant attention. Quantitative research on ice cap mass changes is critical in global climate change. In this study, GRACE JPL RL06 data under the Mascon scheme based on the dynamic method were used. Greenland, which is highly sensitive to climate change, was selected as the study area. Greenland was divided into six sub-research regions, according to its watersheds. The spatial–temporal mass changes were compared to corresponding temperature and precipitation statistics to analyze the relationship between changes in ice sheet mass and climate change. The results show that: (i) From February 2002 to September 2019, the rate of change in the Greenland Ice Sheet mass was about −263 ± 13 Gt yr−1 and the areas with the most substantial ice sheet loss and climate changes were concentrated in the western and southern parts of Greenland. (ii) The mass balance of the Greenland Ice Sheet during the study period was at a loss, and this was closely related to increasing trends in temperature and precipitation. (iii) In the coastal areas of western and southern Greenland, the rate of mass change has accelerated significantly, mainly because of climate change.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yanfei Li ◽  
Zhaohua Li ◽  
Zhihui Li ◽  
Xiaoli Geng ◽  
Xiangzheng Deng

The climatic effects of LUCC have been a focus of current researches on global climate change. The objective of this study is to investigate climatic effects of grassland degradation in Northwest China. Based on the stimulation of the conversion from grassland to other land use types during the next 30 years, the potential effects of grassland degradation on regional climate in the overgrazing area of Northwest China from 2010 to 2040 have been explored with Weather Research and Forecasting model (WRF). The analysis results show that grassland will mainly convert into barren land, croplands, and urban land, which accounts for 42%, 48%, and 10% of the total converted grassland area, respectively. The simulation results indicate that the WRF model is appropriate for the simulation of the impact of grassland degradation on climate change. The grassland degradation during the next 30 years will result in the decrease of latent heat flux, which will further lead to the increase of temperature in summer, with an increment of 0.4–1.2°C, and the decrease of temperature in winter, with a decrement of 0.2°C. In addition, grassland degradation will cause the decrease of precipitation in both summer and winter, with a decrement of 4–20 mm.


2020 ◽  
Vol 149 ◽  
pp. 03010
Author(s):  
Varduhi Margaryan ◽  
Elena Fedotova

The paper analyzes the peculiarities of formation of the absolute maximum runoff of the Marmarik river evaluates the patterns of multi-year fluctuations of maximum runoff rates in different river sites and gives a forecast of the maximum runoff in the context of global climate change. Absolute values of the maximum river runoff for different scenarios of climate change are estimated. The actual observational data of Armhydromet for maximum runoff rate, the air temperature and precipitation were used as the source material. As a result of the study, it turned out that there is only a tendency to decrease in the values of maximum runoff. It turned out that for all scenarios and cases in the Marmarik river basin, a different degree of changes in the maximum flow is observed. Moreover, the largest decrease in the maximum runoff of the Marmarik river basin is expected under the conditions of an increase in the average air temperature of the spring season by 2,7—3,9 degrees Celsius and a decrease in the amount of spring atmospheric precipitation by 2,4—2,6 %.


2020 ◽  
Author(s):  
Seaver Wang ◽  
Zeke Hausfather

Abstract. Increasing attention is focusing upon climate tipping elements – large-scale earth systems anticipated to respond through positive feedbacks to anthropogenic climate change by shifting towards new long-term states. In some but not all cases, such changes could produce additional greenhouse gas emissions or radiative forcing that could compound global warming. Developing greater understanding of tipping elements is important for predicting future climate risks. Here we review mechanisms, predictions, impacts, and knowledge gaps associated with ten notable climate tipping elements. We also evaluate which tipping elements are more imminent and whether shifts will likely manifest rapidly or over longer timescales. Some tipping elements are significant to future global climate and will likely affect major ecosystems, climate patterns, and/or carbon cycling within the current century. However, assessments under different emissions scenarios indicate a strong potential to reduce or avoid impacts associated with many tipping elements through climate change mitigation. Most tipping elements do not possess the potential for abrupt future change within years, and some tipping elements are perhaps more accurately termed climate feedbacks. Nevertheless, significant uncertainties remain associated with many tipping elements, highlighting an acute need for further research and modeling to better constrain risks.


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