scholarly journals Chances of Short-Term Cooling Estimated from a Selection of CMIP5-Based Climate Scenarios during 2006–35 over Canada

2015 ◽  
Vol 28 (8) ◽  
pp. 3232-3249 ◽  
Author(s):  
Patrick Grenier ◽  
Ramón de Elía ◽  
Diane Chaumont

Abstract The path toward a warmer global climate is not smooth, but, rather, is made up of a succession of positive and negative temperature trends, with cooling having more chance to occur the shorter the time scale considered. In this paper, estimates of the probabilities of short-term cooling (Pcool) during the period 2006–35 are performed for 5146 locations across Canada. Probabilities of cooling over durations from 5 to 25 yr come from an ensemble of 60 climate scenarios, based on three different methods using a gridded observational product and CMIP5 climate simulations. These methods treat interannual variability differently, and an analysis in hindcast mode suggests they are relatively reliable. Unsurprisingly, longer durations imply smaller Pcool values; in the case of annual temperatures, the interdecile range of Pcool values across Canada is, for example, ~2%–18% for 25 yr and ~40%–46% for 5 yr. Results vary slightly with the scenario design method, with similar geographical patterns emerging. With regards to seasonal influence, spring and winter are generally associated with higher Pcool values. Geographical Pcool patterns and their seasonality are explained in terms of the interannual variability over background trend ratio. This study emphasizes the importance of natural variability superimposed on anthropogenically forced long-term trends and the fact that regional and local short-term cooling trends are to be expected with nonnegligible probabilities.

2018 ◽  
Vol 4 (1) ◽  
pp. 82-100
Author(s):  
Roberto San José ◽  
◽  
Juan L. Pérez ◽  
Libia Pérez ◽  
Rosa Maria Gonzalez Barras ◽  
...  

2003 ◽  
Vol 34 (5) ◽  
pp. 399-412 ◽  
Author(s):  
M. Rummukainen ◽  
J. Räisänen ◽  
D. Bjørge ◽  
J.H. Christensen ◽  
O.B. Christensen ◽  
...  

According to global climate projections, a substantial global climate change will occur during the next decades, under the assumption of continuous anthropogenic climate forcing. Global models, although fundamental in simulating the response of the climate system to anthropogenic forcing are typically geographically too coarse to well represent many regional or local features. In the Nordic region, climate studies are conducted in each of the Nordic countries to prepare regional climate projections with more detail than in global ones. Results so far indicate larger temperature changes in the Nordic region than in the global mean, regional increases and decreases in net precipitation, longer growing season, shorter snow season etc. These in turn affect runoff, snowpack, groundwater, soil frost and moisture, and thus hydropower production potential, flooding risks etc. Regional climate models do not yet fully incorporate hydrology. Water resources studies are carried out off-line using hydrological models. This requires archived meteorological output from climate models. This paper discusses Nordic regional climate scenarios for use in regional water resources studies. Potential end-users of water resources scenarios are the hydropower industry, dam safety instances and planners of other lasting infrastructure exposed to precipitation, river flows and flooding.


Author(s):  
Alice C. Hill ◽  
Leonardo Martinez-Diaz

Even under the most optimistic scenarios, significant global climate change is now inevitable. Although we cannot tell with certainty how much average global temperatures will rise, we do know that the warming we have experienced to date has already caused significant losses, and that the failure to prepare for the consequences of further warming may prove to be staggering. This book does not dwell on overhyped descriptions of apocalyptic climate scenarios, nor does it travel down well-trodden paths surrounding the politics of reducing carbon emissions. Instead, it starts with two central facts: there will be future climate impacts, and we can make changes now to buffer their effects. While squarely confronting the scale of the risks we face, this pragmatic guide focuses on solutions—some gradual and some more revolutionary—currently being deployed around the globe. Each chapter presents a thematic lesson for decision-makers and engaged citizens to consider, outlining replicable successes and identifying provocative recommendations to strengthen climate resilience. Between discussions of ideas as wide-ranging as managed retreat from coastal hot zones to biological solutions for resurgent climate-related disease threats, the authors draw on their personal experiences to tell behind-the-scenes stories of what it really takes to advance progress on these issues. The narrative is dotted with stories of on-the-ground citizenry, from small-town mayors and bankers to generals and engineers, who are chipping away at financial disincentives and bureaucratic hurdles to prepare for life on a warmer planet.


Author(s):  
Mario A. Carvajal ◽  
Alberto J. Alaniz ◽  
Constanza Gutierrez-Gomez ◽  
Pablo M. Vergara ◽  
Veerasamy Sejian ◽  
...  

2017 ◽  
Vol 30 (19) ◽  
pp. 7777-7799 ◽  
Author(s):  
Jitendra Kumar Meher ◽  
Lalu Das ◽  
Javed Akhter ◽  
Rasmus E. Benestad ◽  
Abdelkader Mezghani

Abstract The western Himalayan region (WHR) was subject to a significant negative trend in the annual and monsoon rainfall during 1902–2005. Annual and seasonal rainfall change over the WHR of India was estimated using 22 rain gauge station rainfall data from the India Meteorological Department. The performance of 13 global climate models (GCMs) from phase 3 of the Coupled Model Intercomparison Project (CMIP3) and 42 GCMs from CMIP5 was evaluated through multiple analysis: the evaluation of the mean annual cycle, annual cycles of interannual variability, spatial patterns, trends, and signal-to-noise ratio. In general, CMIP5 GCMs were more skillful in terms of simulating the annual cycle of interannual variability compared to CMIP3 GCMs. The CMIP3 GCMs failed to reproduce the observed trend, whereas approximately 50% of the CMIP5 GCMs reproduced the statistical distribution of short-term (30 yr) trend estimates than for the longer-term (99 yr) trends from CMIP5 GCMs. GCMs from both CMIP3 and CMIP5 were able to simulate the spatial distribution of observed rainfall in premonsoon and winter months. Based on performance, each model of CMIP3 and CMIP5 was given an overall rank, which puts the high-resolution version of the MIROC3.2 model [MIROC3.2 (hires)] and MIROC5 at the top in CMIP3 and CMIP5, respectively. Robustness of the ranking was judged through a sensitivity analysis, which indicated that ranks were independent during the process of adding or removing any individual method. It also revealed that trend analysis was not a robust method of judging performances of the models as compared to other methods.


2017 ◽  
Author(s):  
Ran Zhai ◽  
Fulu Tao ◽  
Zhihui Xu

Abstract. The Paris Agreement set a long-term temperature goal of holding the global average temperature increase to below 2.0 ℃ above pre-industrial levels, and pursuing efforts to limit this to 1.5 ℃, it is therefore important to understand the impacts of climate change under 1.5 ℃ and 2.0 ℃ warming scenarios for climate adaptation and mitigation. Here, climate scenarios by four Global Circulation Models (GCMs) for the baseline (2006–2015), 1.5 ℃ and 2.0 ℃ warming scenarios (2106–2115) were used to drive the validated Variable Infiltration Capacity (VIC) hydrological model to investigate the impacts of global warming on river runoff and Terrestrial Ecosystem Water Retention (TEWR) in China. The trends in annual mean temperature, precipitation, river runoff and TEWR were analysed at the grid and basin scale. Results showed that there were large uncertainties in climate scenarios from the different GCMs, which led to large uncertainties in the impact assessment. The differences among the four GCMs were larger than differences between the two warming scenarios. The interannual variability of river runoff increased notably in areas where it was projected to increase, and the interannual variability increased notably from 1.5 ℃ warming scenario to 2.0 ℃ warming scenario. By contrast, TEWR would remain relatively stable. Both extreme low and high river runoff would increase under the two warming scenarios in most areas in China, with high river runoff increasing more. And the risk of extreme river runoff events would be higher under 2.0 ℃ warming scenario than under 1.5 ℃ warming scenario in term of both extent and intensity. River runoff was significantly positively correlated to precipitation, while increase in maximum temperature would generally cause river runoff to decrease through increasing evapotranspiration. Likewise, precipitation also played a dominant role in affecting TEWR. Our findings highlight climate change mitigation and adaptation should be taken to reduce the risks of hydrological extreme events.


1984 ◽  
Vol 1 (19) ◽  
pp. 112 ◽  
Author(s):  
Jennifer E. Dick ◽  
Robert A. Dalrymple

The coastal processes affecting Bethany Beach, Delaware were studied and the short-term and long-term trends in coastal changes were determined in order to develop recommendations for protecting Bethany against coastal erosion (Dick and Dalrymple, 1983). Bethany Beach is located on the Delaware Atlantic coastline which is a wide sandy baymouth barrier beach distinguished by highlands at Rehoboth Beach and Bethany Beach. The shoreline is straight, with only minor bulges and indentations (see Figure 1). Bethany Beach is a residential and resort community. Privatelyowned properties front the publicly-owned beach. Construction of new motels and summer homes is anticipated along with the continued growth of commercial activities to accommodate the increased number of visitors. Bethany is protected by a series of nine groins built between 1934 and 1945. Many of these groins have deteriorated, and are flanked at the landward end. Winter storms severely erode the beach and damage shorefront property. The beach is generally narrow (approximately 45 m wide), especially along the southern portion, and is backed by low dunes (about 15-45 m above NGVD). A timber bulkhead extends along most of the backshore.


Eos ◽  
2021 ◽  
Vol 102 ◽  
Author(s):  
Jack Lee

An ensemble of climate simulations identifies factors that drove long-term trends of a prehistoric greenhouse climate.


2007 ◽  
Vol 34 (8) ◽  
pp. 934-945 ◽  
Author(s):  
Louis-Guillaume Fortin ◽  
Richard Turcotte ◽  
Stéphane Pugin ◽  
Jean-François Cyr ◽  
François Picard

This study presents the results of a pilot project, for the Saint-François and Aylmer lakes located in southern Quebec, aimed at developing a method to evaluate the adaptability of a current dam management plan to global climate changes. The hydrological simulations computed using available climate scenarios indicated modifications in annual water yields, from a 13% increase to a 30% decrease, and earlier spring floods. Peak flows, winter and summer low flows, and the level of increase in water yields vary depending on the studied climate scenario. The simulation of the current management plan shows that climate changes will affect the current trade-off between the various management objectives of the reservoirs. Adaptation solutions to the current management plan appeared to be feasible, but no unique solution applicable to all climate scenarios was found.Key words: climate change, dam, impacts, adaptation, hydrologic modeling, Quebec.


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