scholarly journals Climate change in arid environments: revisiting the past to understand the future

2004 ◽  
Vol 28 (4) ◽  
pp. 502-530 ◽  
Author(s):  
Elena Lioubimtseva
Keyword(s):  
Climate Change ◽  
Arid Regions ◽  
Climatic Variability ◽  
Arid Environments ◽  
Climate Feedbacks ◽  
Ecosystem Responses ◽  
The Past ◽  
History Of ◽  
Precipitation Changes ◽  
Climate Change Modelling

Arid regions are expected to undergo significant changes under a scenario of climate warming, but there is considerable variability and uncertainty in these estimates between different scenarios. The complexities of precipitation changes, vegetation-climate feedbacks and direct physiological effects of CO2 on vegetation present particular challenges for climate change modelling of arid regions. Great uncertainties exist in the prediction of arid ecosystem responses to elevated CO2 and global warming. Palaeodata provide important information about the past frequency, intensity and subregional patterns of change in the world’s deserts that cannot always be captured by the climatic models. However, it is important to bear in mind that the global mechanisms of Quaternary climatic variability were different from present-day trends, and any direct analogies between the past and present should be treated with great caution. Although palaeodata provide valuable information about possible past changes in the vegetation-climate system, it is unlikely that the history of the world’s deserts is a key for their future.

The Impacts of Climate Change on Societies: What Can We Learn from the Past?

2021 ◽  
Author(s):  
Dagomar Degroot
Keyword(s):  
Climate Change ◽  
Case Studies ◽  
Public Discourse ◽  
Climate Change Policy ◽  
Ice Cores ◽  
Keynote Presentation ◽  
The Past ◽  
Change Policy ◽  
History Of ◽  
Paleoclimatic Proxy

<p>This keynote presentation introduces the sources, methods, and major findings of the History of Climate and Society (HCS), a recently-coined field that uncovers the past influences of climate change on human history. It begins by offering a brief history of the field, from the eighteenth century through the present. It then describes how HCS scholars “reconstruct” past climate changes by combining what they call the “archives of nature” – paleoclimatic proxy sources such as tree rings, ice cores, or marine sediments – with the texts, stories, and ruins that constitute the “archives of society.” Next, it explains how HCS scholars in different disciplines have used distinct statistical and qualitative methods, and distinct causal frameworks, to identify the influence of climate change in the archives of society. It explores how HCS scholars conceptualize the vulnerability and resilience of past societies by introducing some telling case studies, and explaining how those case studies have grown more complex as HCS matured as a field. It then emphasizes the enduring challenges faced by HCS scholars and how, in recent months, they have been identified and are beginning to be addressed. Finally, it describes how HCS has informed climate change policy and public discourse, before offering some key lessons that policymakers can learn from the field.</p>

scholarly journals Sensitivity of atmospheric aerosol scavenging to precipitation intensity and frequency in the context of global climate change

2017 ◽  
Author(s):  
Pei Hou ◽  
Shiliang Wu ◽  
Jessica L. McCarty
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Atmospheric Aerosols ◽  
Atmospheric Aerosol ◽  
Model Simulation ◽  
Global Climate ◽  
Regional Scale ◽  
Precipitation Intensity ◽  
The Past ◽  
Precipitation Changes

Abstract. Wet deposition driven by precipitation is an important sink for atmospheric aerosols and soluble gases. We investigate the sensitivity of atmospheric aerosol lifetimes to precipitation intensity and frequency in the context of global climate change. Our study, based on the GEOS-Chem model simulation, shows that the removal efficiency and hence the atmospheric lifetime of aerosols have significantly higher sensitivities to precipitation frequencies than to precipitation intensities, indicating that the same amount of precipitation may lead to different removal efficiencies of atmospheric aerosols. Combining the long-term trends of precipitation patterns for various regions with the sensitivities of atmospheric aerosols lifetimes to various precipitation characteristics allows us to examine the potential impacts of precipitation changes on atmospheric aerosols. Analyses based on an observational dataset show that precipitation frequency in some regions have decreased in the past 14 years, which might increase the atmospheric aerosol lifetimes in those regions. Similar analyses based on multiple reanalysis meteorological datasets indicate that the precipitation changes over the past 30 years can lead to perturbations in the atmospheric aerosol lifetimes by 10 % or higher at the regional scale.

scholarly journals Application of dendroclimatology in evaluation of climatic changes

2018 ◽  
Vol 64 (No. 3) ◽  
pp. 139-147 ◽  
Author(s):  
Khaleghi Mohammad Reza
Keyword(s):  
Climate Change ◽  
Tree Rings ◽  
Arid Regions ◽  
Ring Width ◽  
Climatic Changes ◽  
The Past ◽  
Temperature And Precipitation ◽  
Temporal And Spatial ◽  
Artificial Neural Network Ann ◽  
High Degree

The present study tends to describe the survey of climatic changes in the case of the Bojnourd region of North Khorasan, Iran. Climate change due to a fragile ecosystem in semi-arid and arid regions such as Iran is one of the most challenging climatological and hydrological problems. Dendrochronology, which uses tree rings to their exact year of formation to analyse temporal and spatial patterns of processes in the physical and cultural sciences, can be used to evaluate the effects of climate change. In this study, the effects of climate change were simulated using dendrochronology (tree rings) and an artificial neural network (ANN) for the period from 1800 to 2015. The present study was executed using the Quercus castaneifolia C.A. Meyer. Tree-ring width, temperature, and precipitation were the input parameters for the study, and climate change parameters were the outputs. After the training process, the model was verified. The verified network and tree rings were used to simulate climatic parameter changes during the past times. The results showed that the integration of dendroclimatology and an ANN renders a high degree of accuracy and efficiency in the simulation of climate change. The results showed that in the last two centuries, the climate of the study area changed from semiarid to arid, and its annual precipitation decreased significantly.

Small peatland with a big story: 600-year paleoecological and historical data from a kettle-hole peatland in Western Russia

The Holocene ◽  
2021 ◽  
pp. 095968362110332
Author(s):  
Agnieszka Mroczkowska ◽  
Piotr Kittel ◽  
Katarzyna Marcisz ◽  
Ekaterina Dolbunova ◽  
Emilie Gauthier ◽  
...  
Keyword(s):  
Human Impact ◽  
Human Activities ◽  
Environmental Changes ◽  
Climatic Variability ◽  
Testate Amoebae ◽  
The Past ◽  
Kettle Hole ◽  
Rapid Changes ◽  
History Of ◽  
Physical And Chemical

Peatlands are important records of past environmental changes. Based on a multiproxy analysis, the main factors influencing the evolution of a peatland can be divided into autogenic and allogenic. Among the important allogenic factors, apart from climate change, are deforestation and drainage, which are directly associated with human impact. Numerous consequences arise from these processes, the most important of which are physical and chemical denudation in the catchment and the related hydrological disturbances in the catchment and peatland. The present study determined how human activities and the past climatic variability mutually influenced the development of a small peatland ecosystem. The main goals of the study were: (1) to trace the local changes of the peatland history over the past 600 years, (2) to investigate their relationship with changes in regional hydroclimate patterns, and (3) to estimate the sensitivity of a small peatland to natural and human impact. Our reconstructions were based on a multiproxy analysis, including the analysis of pollen, macrofossils, Chironomidae, Cladocera, and testate amoebae. Our results showed that, depending on the changes in water level, the history of peatland can be divided into three phases as follows: 1/the phase of stable natural conditions, 2/phase of weak changes, and 3/phase of significant changes in the catchment. Additionally, to better understand the importance of the size of catchment and the size of the depositional basin in the evolution of the studied peatland ecosystem, we compared data from two peatlands – large and small – located close to each other. The results of our study indicated that “size matters,” and that larger peatlands are much more resilient and resistant to rapid changes occurring in the direct catchment due to human activities, whereas small peatlands are more sensitive and perfect as archives of environmental changes.

scholarly journals Computer-assisted detection and classification of misinformation about climate change

2021 ◽  
Author(s):  
Travis Coan ◽  
Constantine Boussalis ◽  
John Cook ◽  
Mirjam Nanko
Keyword(s):  
Climate Change ◽  
Climate Science ◽  
Computer Assisted ◽  
Think Tank ◽  
Detailed History ◽  
The Past ◽  
Computer Assisted Detection ◽  
History Of

A growing body of scholarship investigates the role of misinformation in shaping the debate on climate change. Our research builds on and extends this literature by 1) developing and validating a comprehensive taxonomy of climate misinformation, 2) conducting the largest content analysis to date on contrarian claims, 3) developing a computational model to accurately detect specific claims, and 4) drawing on an extensive corpus from conservative think-tank (CTTs) websites and contrarian blogs to construct a detailed history of misinformation over the past 20 years. Our study finds that climate misinformation produced by CTTs and contrarian blogs has focused on attacking the integrity of climate science and scientists and, increasingly, has challenged climate policy and renewable energy. We further demonstrate the utility of our approach by exploring the influence of corporate and foundation funding on the production and dissemination of specific contrarian claims.

scholarly journals Sensitivity of atmospheric aerosol scavenging to precipitation intensity and frequency in the context of global climate change

2018 ◽  
Vol 18 (11) ◽  
pp. 8173-8182 ◽  
Author(s):  
Pei Hou ◽  
Shiliang Wu ◽  
Jessica L. McCarty ◽  
Yang Gao
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Atmospheric Aerosols ◽  
Atmospheric Aerosol ◽  
Global Climate ◽  
Regional Scale ◽  
Precipitation Intensity ◽  
The Past ◽  
Long Term Trends ◽  
Precipitation Changes

Abstract. Wet deposition driven by precipitation is an important sink for atmospheric aerosols and soluble gases. We investigate the sensitivity of atmospheric aerosol lifetimes to precipitation intensity and frequency in the context of global climate change. Our sensitivity model simulations, through some simplified perturbations to precipitation in the GEOS-Chem model, show that the removal efficiency and hence the atmospheric lifetime of aerosols have significantly higher sensitivities to precipitation frequencies than to precipitation intensities, indicating that the same amount of precipitation may lead to different removal efficiencies of atmospheric aerosols. Combining the long-term trends of precipitation patterns for various regions with the sensitivities of atmospheric aerosol lifetimes to various precipitation characteristics allows us to examine the potential impacts of precipitation changes on atmospheric aerosols. Analyses based on an observational dataset show that precipitation frequencies in some regions have decreased in the past 14 years, which might increase the atmospheric aerosol lifetimes in those regions. Similar analyses based on multiple reanalysis meteorological datasets indicate that the changes of precipitation intensity and frequency over the past 30 years can lead to perturbations in the atmospheric aerosol lifetimes by 10 % or higher at the regional scale.

scholarly journals Computer-assisted classification of contrarian claims about climate change

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Travis G. Coan ◽  
Constantine Boussalis ◽  
John Cook ◽  
Mirjam O. Nanko
Keyword(s):  
Climate Change ◽  
Climate Science ◽  
Computer Assisted ◽  
Think Tank ◽  
Detailed History ◽  
The Past ◽  
Growing Body ◽  
History Of

AbstractA growing body of scholarship investigates the role of misinformation in shaping the debate on climate change. Our research builds on and extends this literature by (1) developing and validating a comprehensive taxonomy of climate contrarianism, (2) conducting the largest content analysis to date on contrarian claims, (3) developing a computational model to accurately classify specific claims, and (4) drawing on an extensive corpus from conservative think-tank (CTTs) websites and contrarian blogs to construct a detailed history of claims over the past 20 years. Our study finds that the claims utilized by CTTs and contrarian blogs have focused on attacking the integrity of climate science and scientists and, increasingly, has challenged climate policy and renewable energy. We further demonstrate the utility of our approach by exploring the influence of corporate and foundation funding on the production and dissemination of specific contrarian claims.

Biodiverse, productive, and socially just silvopastures: a solution for the Brazilian drylands

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Felipe Machado Pinheiro ◽  
Patrick Hunt
Keyword(s):  
Climate Change ◽  
Agricultural Development ◽  
Green Revolution ◽  
Biodiversity Loss ◽  
The Past ◽  
Suggested Strategy ◽  
History Of ◽  
Multiple Variables ◽  
Interdisciplinary Projects ◽  
Impacts Of Climate Change

Drylands constitute more than 40% of global land and are particularly vulnerable to the impacts of climate change. In many of these drylands, livestock activities are a major form of land-use. In Brazil, the two major dryland biomes, Cerrado and Caatinga, play a key role in the country’s livestock activities. While important economically, these activities also contribute to the emission of high amounts of greenhouse gases. One suggested strategy for mitigating the impacts of climate change is the adoption of silvopastoral systems (SPS) which combine trees, pasture, and animals simultaneously on the same unit of land. Farmers in the drylands of Brazil have a long history of practicing SPS. The practice of silvopasture is relevant to both climate change and the economy, but not necessarily to the issues of biodiversity loss and economic inequality. The lack of interdisciplinarity in rural agricultural development projects in the past, such as those related to the “Green Revolution”, resulted in the aggravation of economic inequalities and biodiversity loss. The present work, focusing on the Brazilian Drylands, reviews these issues to justify the need for interdisciplinary projects considering multiple variables like soil quality, tree density, biodiversity richness, and farmers’ perception. 

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