Response of the Everglades ridge and slough landscape to climate variability and 20th-century water management

2009 ◽  
Vol 19 (7) ◽  
pp. 1723-1738 ◽  
Author(s):  
Christopher E. Bernhardt ◽  
Debra A. Willard
Keyword(s):  
Water Management ◽  
Climate Variability ◽  
20Th Century ◽  
Ridge And Slough

scholarly journals The implication of climate variability on household water management; perception and practices among rural womenfolk in four communities in Ghana

2019 ◽  
Vol 5 (1) ◽  
pp. 1603607
Author(s):  
Karyn E. Quansah ◽  
Chris Gordon ◽  
Fred Aboagye-Antwi ◽  
Rex Gerchie ◽  
Philip Louis Staddon
Keyword(s):  
Water Management ◽  
Climate Variability ◽  
Household Water

scholarly journals Dendroclimatology in the Eastern Mediterranean

Radiocarbon ◽  
2014 ◽  
Vol 56 (04) ◽  
pp. S61-S68
Author(s):  
Ramzi Touchan ◽  
David M. Meko ◽  
Kevin J. Anchukaitis
Keyword(s):  
Resource Management ◽  
Climate Variability ◽  
20Th Century ◽  
Tree Ring ◽  
Large Scale ◽  
Eastern Mediterranean ◽  
Spatial Scales ◽  
Climatic Variation ◽  
Ring Network ◽  
The Past

Dendroclimatology in the Eastern Mediterranean (EM) region has made important contributions to the understanding of climate variability on timescales of decades to centuries. These contributions, beginning in the mid-20th century, have value for resource management, archaeology, and climatology. A gradually expanding tree-ring network developed by the first author over the past 15 years has been the framework for some of the most important recent advances in EM dendroclimatology. The network, now consisting of 79 sites, has been widely applied in large-scale climatic reconstruction and in helping to identify drivers of climatic variation on regional to global spatial scales. This article reviews EM dendroclimatology and highlights contributions on the national and international scale.

scholarly journals Response of Subalpine Conifers in the Sierra Nevada, California, U.S.A., to 20th-Century Warming and Decadal Climate Variability

2004 ◽  
Vol 36 (2) ◽  
pp. 181-200 ◽  
Author(s):  
Constance I. Millar ◽  
Robert D. Westfall ◽  
Diane L. Delany ◽  
John C. King ◽  
Lisa J. Graumlich
Keyword(s):  
Climate Variability ◽  
20Th Century ◽  
Sierra Nevada ◽  
Decadal Climate Variability ◽  
Decadal Climate

scholarly journals Glacier response to North Atlantic climate variability during the Holocene

2015 ◽  
Vol 11 (3) ◽  
pp. 2009-2036 ◽  
Author(s):  
N. L. Balascio ◽  
W. J. D'Andrea ◽  
R. S. Bradley
Keyword(s):  
Climate Variability ◽  
20Th Century ◽  
Northern Hemisphere ◽  
North Atlantic ◽  
Late Holocene ◽  
North Atlantic Ocean ◽  
The Holocene ◽  
The Past ◽  
Summer Insolation ◽  
Geochemical Parameters

Abstract. Small glaciers and ice caps respond rapidly to climate variations and records of their past extent provide information on the natural envelope of past climate variability. Millennial-scale trends in Holocene glacier size are well documented and correspond with changes in Northern Hemisphere summer insolation. However, there is only sparse and fragmentary evidence for higher frequency variations in glacier size because in many Northern Hemisphere regions glacier advances of the past few hundred years were the most extensive and destroyed the geomorphic evidence of ice growth and retreat during the past several thousand years. Thus, most glacier records have been of limited use for investigating centennial scale climate forcing and feedback mechanisms. Here we report a continuous record of glacier activity for the last 9.5 ka from southeast Greenland, derived from high-resolution measurements on a proglacial lake sediment sequence. Physical and geochemical parameters show that the glaciers responded to previously documented Northern Hemisphere climatic excursions, including the "8.2 ka" cooling event, the Holocene Thermal Maximum, Neoglacial cooling, and 20th Century warming. In addition, the sediments indicate centennial-scale oscillations in glacier size during the late Holocene. Beginning at 4.1 ka, a series of abrupt glacier advances occurred, each lasting ~100 years and followed by a period of retreat, that were superimposed on a gradual trend toward larger glacier size. Thus, while declining summer insolation caused long-term cooling and glacier expansions during the late Holocene, climate system dynamics resulted in repeated episodes of glacier expansion and retreat on multi-decadal to centennial timescales. These episodes coincided with ice rafting events in the North Atlantic Ocean and periods of regional ice cap expansion, which confirms their regional significance and indicates that considerable glacier activity on these timescales is a normal feature of the cryosphere. The data provide a longer-term perspective on the rate of 20th century glacier retreat and indicate that recent anthropogenic-driven warming has already impacted the regional cryosphere in a manner outside the natural range of Holocene variability.

scholarly journals Anthropogenic aerosol forcing of the AMOC and the associated mechanisms in CMIP6 models

2020 ◽  
Author(s):  
Taufiq Hassan ◽  
Robert J. Allen ◽  
Wei Liu ◽  
Cynthia Randles
Keyword(s):  
Climate Variability ◽  
Atmospheric Circulation ◽  
20Th Century ◽  
North Atlantic ◽  
Meridional Overturning Circulation ◽  
Solar Variability ◽  
Anthropogenic Aerosols ◽  
Anthropogenic Aerosol ◽  
Aerosol Forcing ◽  
Volcanic Aerosols

Abstract. By regulating the global transport of heat, freshwater and carbon, the Atlantic Meridional Overturning Circulation (AMOC) serves as an important component of the climate system. During the late 20th and early 21st centuries, indirect observations and models suggest a weakening of the AMOC. Direct AMOC observations also suggest a weakening during the early 21st century, but with substantial interannual variability. Long-term weakening of the AMOC has been associated with increasing greenhouse gases (GHGs), but some modeling studies suggest the build up of anthropogenic aerosols (AAs) may have offset part of the GHG-induced weakening. Here, we quantify 1900–2020 AMOC variations and assess the driving mechanisms in state-of-the-art climate models from the Coupled Model Intercomparison Project phase 6 (CMIP6). The CMIP6 all forcing (GHGs, anthropogenic and volcanic aerosols, solar variability, and land use/land change) multi-model mean shows negligible AMOC changes up to ~1950, followed by robust AMOC strengthening during the second half of the 20th century (~1950–1990), and weakening afterwards (1990–2020). These multi-decadal AMOC variations are related to changes in North Atlantic atmospheric circulation, including an altered sea level pressure gradient, storm track activity, surface winds and heat fluxes, which drive changes in the subpolar North Atlantic surface density flux. Similar to previous studies, CMIP6 GHG simulations yield robust AMOC weakening, particularly during the second half of the 20th century. Changes in natural forcings, including solar variability and volcanic aerosols, yield negligible AMOC changes. In contrast, CMIP6 AA simulations yield robust AMOC strengthening (weakening) in response to increasing (decreasing) anthropogenic aerosols. Moreover, the CMIP6 all-forcing AMOC variations and atmospheric circulation responses also occur in the CMIP6 AA simulations, which suggests these are largely driven by changes in anthropogenic aerosol emissions. Although aspects of the CMIP6 all-forcing multi-model mean response resembles observations, notable differences exist. This includes CMIP6 AMOC strengthening from ~1950–1990, when the indirect estimates suggest AMOC weakening. The CMIP6 multi-model mean also underestimates the observed increase in North Atlantic ocean heat content. And although the CMIP6 North Atlantic atmospheric circulation responses–particularly the overall patterns–are similar to observations, the simulated responses are weaker than those observed, implying they are only partially externally forced. The possible causes of these differences include internal climate variability, observational uncertainties and model shortcomings–including excessive aerosol forcing. A handful of CMIP6 realizations yield AMOC evolution since 1900 similar to the indirect observations, implying the inferred AMOC weakening from 1950–1990 (and even from 1930–1990) may have a significant contribution from internal (i.e., unforced) climate variability. Nonetheless, CMIP6 models yield robust, externally forced AMOC changes, the bulk of which are due to anthropogenic aerosols.

scholarly journals Droughts and governance impacts on water scarcity: an~analysis in the Brazilian semi-arid

2015 ◽  
Vol 369 ◽  
pp. 129-134 ◽  
Author(s):  
A. C. S. Silva ◽  
C. O. Galvão ◽  
G. N. S. Silva
Keyword(s):  
Climate Change ◽  
Water Management ◽  
Climate Variability ◽  
Extreme Events ◽  
Water Scarcity ◽  
Ecological Systems ◽  
Drought Event ◽  
Social Ecological Systems ◽  
Social Ecological ◽  
Semi Arid

Abstract. Extreme events are part of climate variability. Dealing with variability is still a challenge that might be increased due to climate change. However, impacts of extreme events are not only dependent on their variability, but also on management and governance. In Brazil, its semi-arid region is vulnerable to extreme events, especially droughts, for centuries. Actually, other Brazilian regions that have been mostly concerned with floods are currently also experiencing droughts. This article evaluates how a combination between climate variability and water governance might affect water scarcity and increase the impacts of extreme events on some regions. For this evaluation, Ostrom's framework for analyzing social-ecological systems (SES) was applied. Ostrom's framework is useful for understanding interactions between resource systems, governance systems and resource users. This study focuses on social-ecological systems located in a drought-prone region of Brazil. Two extreme events were selected, one in 1997–2000, when Brazil's new water policy was very young, and the other one in 2012–2015. The analysis of SES considering Ostrom's principle "Clearly defined boundaries" showed that deficiencies in water management cause the intensification of drought's impacts for the water users. The reasons are more related to water management and governance problems than to drought event magnitude or climate change. This is a problem that holdup advances in dealing with extreme events.

Command-scale integrated water management in response to spatial climate variability in Lower Bari Doab Canal irrigation system

Water Policy ◽  
2013 ◽  
Vol 16 (2) ◽  
pp. 374-396 ◽  
Author(s):  
Muhammad Basharat ◽  
Ata-Ur-Rehman Tariq
Keyword(s):  
Water Management ◽  
Climate Variability ◽  
Irrigation System ◽  
Indus Basin ◽  
Integrated Water Management ◽  
Canal Irrigation ◽  
Irrigation Cost ◽  
Groundwater Regime ◽  
Basin Irrigation ◽  
Scale Integration

Design and management of the Indus Basin Irrigation System are aimed at achieving equity in canal water supply. This concept, which is more than a century old, ignores the due aspect of groundwater management in today's perspective. Recent research has proved that variation in irrigation demand and rainfall within the irrigation units has given birth to varying stresses on groundwater. In response to spatial climate variability, reallocation of canal supplies from the head towards the tail of the Lower Bari Doab Canal (LBDC) command was evaluated in this study, with the objective of achieving equitable total irrigation costs. The ensuing groundwater regime was simulated for 50 years' time with a groundwater model. A 25% reallocation from head towards tail-end improves the standard deviation of total irrigation cost equity from 1905 to 241. This command scale integration of available water resources also demonstrated a net saving in groundwater pumping cost to the tune of 7.24 to 18.9%, in comparison with existing equitable canal supplies. With this approach, at least minimal or no waterlogging in the head-end area, even during wet years, and no groundwater mining in the tail-end, even during dry periods, are anticipated. In addition, this system-scale integrated water management would increase adaptive capacity to climate change adaptation.

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