scholarly journals Impacts on agriculture

2013 ◽  
Vol 125 (1) ◽  
pp. 24
Author(s):  
Leanne Webb
Keyword(s):  
Extreme Events ◽  
Agricultural Production ◽  
Climate Models ◽  
Climate Extremes ◽  
Extreme Rainfall ◽  
Agricultural Communities ◽  
Eastern Australia ◽  
Weather And Climate ◽  
Challenging Environment ◽  
Mean Climate

p>Agricultural production in Victoria includes the dairy, lamb and mutton, grains and perennial and annual horticultural sectors, with Victorian farmers contributing a major proportion of the Australian production total in many of these sectors. All these industries are exposed in different ways to weather and climate extremes. With projected warming of approximately 0.8°C by 2030 and by 1.4–2.7°C by 2070 (emissions dependent), and most climate models indicating reduced rainfall for the Victorian region (median of model results projecting a reduction of 4% by 2030 and 6%–11% by 2070; emissions dependent), a range of sectorspecific impacts could result. Increases in extreme events, such as heatwaves (e.g. for Mildura, days >35°C could nearly double from 32 to 59 annually by 2070), bushfires and drought, as well as an increased chance of extreme rainfall are all anticipated. Increasing frequencies of extreme events have the potential to affect agricultural production more than changes to the mean climate. For example, the exceptional heatwave that occurred in south-eastern Australia during January and February 2009 resulted in unprecedented impacts, with significant heat-stress related crop losses reported at many sites. Flooding in 2011 was also very costly to Victorian farmers with many crops being lost in the floodwaters and reduced agricultural production costing an estimated Au$500–600 million. Responses to climate variability already practised by the farming sector will inform some adaptation options that will assist farmers to cope in an increasingly challenging environment. As well as taking advantage of their underlying resilience, initiatives aimed at increasing the adaptive capacity of farmers are being implemented at many levels in agricultural communities.

A complex network analysis of extreme cyclones in the Arctic

2021 ◽  
Author(s):  
Dörthe Handorf ◽  
Ozan Sahin ◽  
Annette Rinke ◽  
Jürgen Kurths
Keyword(s):  
Complex Network ◽  
Northern Hemisphere ◽  
Extreme Events ◽  
Geopotential Height ◽  
Winter Season ◽  
Climate Extremes ◽  
The Arctic ◽  
Weather And Climate ◽  
Class 1 ◽  
Height Fields

<p>Under the rapid and amplified warming of the Arctic, changes in the occurrence of Arctic weather and climate extremes are evident which have substantial cryospheric and biophysical impacts like floods, droughts, coastal erosion or wildfires. Furthermore, these changes in weather and climate extremes have the potential to further amplify Arctic warming. <br>Here we study extreme cyclone events in the Arctic, which often occur during winter and are associated with extreme warming events that are caused by cyclone-related heat and moisture transport into the Arctic. In that way Arctic extreme cyclones have the potential to retard sea-ice growth in autumn and winter or to initiate an earlier melt-season onset. <br>To get a better understanding of these extreme cyclones and their occurrences in the Arctic, it is important to reveal the related atmospheric teleconnection patterns and understand their underlying mechanisms. In this study, the methodology of complex networks is used to identify teleconnections associated with extreme cyclones events (ECE) over Spitzbergen. We have chosen Spitzbergen, representative for the Arctic North Atlantic region which is a hot spot of Arctic climate change showing also significant recent changes in the occurrence of extreme cyclone events. <br>Complex climate networks have been successfully applied in the analysis of climate teleconnections during the last decade. To analyze time series of unevenly distributed extreme events, event synchronization (ES) networks are appropriate. Using this framework, we analyze the spatial patterns of significant synchronization between extreme cyclone events over the Spitzbergen area and extreme events in sea-level pressure (SLP) in the rest of the Northern hemisphere for the extended winter season from November to March. Based on the SLP fields from the newest atmospheric reanalysis ERA5, we constructed the ES networks over the time period 1979-2019.<br>The spatial features of the complex network topology like Eigenvector centrality, betweenness centrality and network divergence are determined and their general relation to storm tracks, jet streams and waveguides position is discussed. Link bundles in the maps of statistically significant links of ECEs over Spitzbergen with the rest of the Northern Hemisphere have revealed two classes of teleconnections: Class 1 comprises links from various regions of the Northern hemisphere to Spitzbergen, class 2 comprises links from Spitzbergen to various regions of the Northern hemisphere. For each class three specific teleconnections have been determined. By means of composite analysis, the corresponding atmospheric conditions are characterized.<br>As representative of class 1, the teleconnection between extreme events in SLP over the subtropical West Pacific and delayed ECEs at Spitzbergen is investigated. The corresponding lead-lag analysis of atmospheric fields of SLP, geopotential height fields and meridional wind fields suggests that the class 1 teleconnections are caused by tropical forcing of poleward emanating Rossby wave trains. As representative of class 2, the teleconnection between ECEs at Spitzbergen and delayed extreme events in SLP over Northwest Russia is analyzed. The corresponding lead-lag analysis of atmospheric fields of SLP and geopotential height fields from the troposphere to the stratosphere suggests that the class 2 teleconnections are caused by troposphere-stratosphere coupling processes.</p>

Climate Extremes and Compound Hazards in a Warming World

2020 ◽  
Vol 48 (1) ◽  
pp. 519-548 ◽  
Author(s):  
Amir AghaKouchak ◽  
Felicia Chiang ◽  
Laurie S. Huning ◽  
Charlotte A. Love ◽  
Iman Mallakpour ◽  
...  
Keyword(s):  
Extreme Events ◽  
Climate Models ◽  
Heat Waves ◽  
Climate Extremes ◽  
Well Being ◽  
Theoretical Research ◽  
Aging Infrastructure ◽  
Climate Hazards ◽  
Projected Changes ◽  
Warming World

Climate extremes threaten human health, economic stability, and the well-being of natural and built environments (e.g., 2003 European heat wave). As the world continues to warm, climate hazards are expected to increase in frequency and intensity. The impacts of extreme events will also be more severe due to the increased exposure (growing population and development) and vulnerability (aging infrastructure) of human settlements. Climate models attribute part of the projected increases in the intensity and frequency of natural disasters to anthropogenic emissions and changes in land use and land cover. Here, we review the impacts, historical and projected changes,and theoretical research gaps of key extreme events (heat waves, droughts, wildfires, precipitation, and flooding). We also highlight the need to improve our understanding of the dependence between individual and interrelated climate extremes because anthropogenic-induced warming increases the risk of not only individual climate extremes but also compound (co-occurring) and cascading hazards. ▪  Climate hazards are expected to increase in frequency and intensity in a warming world. ▪  Anthropogenic-induced warming increases the risk of compound and cascading hazards. ▪  We need to improve our understanding of causes and drivers of compound and cascading hazards.

scholarly journals Weather and Climate Extremes: Current Developments

Atmosphere ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 24 ◽  
Author(s):  
Drumond ◽  
Liberato ◽  
Reboita ◽  
Taschetto
Keyword(s):  
Global Warming ◽  
Extreme Events ◽  
Climate Extremes ◽  
The Past ◽  
Weather And Climate ◽  
The World

An increasing number of extreme events have been observed around the world over the past few decades, some of them attributed to global warming [...]

scholarly journals Monitoring the impacts of weather and climate extremes on global agricultural production

2015 ◽  
Vol 10 ◽  
pp. 65-71 ◽  
Author(s):  
Robert Johansson ◽  
Eric Luebehusen ◽  
Brian Morris ◽  
Harlan Shannon ◽  
Seth Meyer
Keyword(s):  
Agricultural Production ◽  
Climate Extremes ◽  
Weather And Climate

Has the climate become more variable or extreme? Progress 1992-2006

2007 ◽  
Vol 31 (1) ◽  
pp. 77-87 ◽  
Author(s):  
Neville Nicholls ◽  
Lisa Alexander
Keyword(s):  
Climate Change ◽  
Extreme Events ◽  
Climate Extremes ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Intergovernmental Panel ◽  
Weather Events ◽  
Weather And Climate ◽  
Analyse Data ◽  
Climate Events

In 1990 and 1992 the Intergovernmental Panel on Climate Change (IPCC), in its first assessment of climate change and its supplement, did not consider whether extreme weather events had increased in frequency and/or intensity globally, because data were too sparse to make this a worthwhile exercise. In 1995 the IPCC, in its second assessment, did examine this question, but concluded that data and analyses of changes in extreme events were ‘not comprehensive’and thus the question could not be answered with any confidence. Since then, concerted multinational efforts have been undertaken to collate, quality control, and analyse data on weather and climate extremes. A comprehensive examination of the question of whether extreme events have changed in frequency or intensity is now more feasible than it was 15 years ago. The processes that have led to this position are described, along with current understanding of possible changes in some extreme weather and climate events.

scholarly journals Changes in the Risk of Extratropical Cyclones in Eastern Australia

2013 ◽  
Vol 26 (4) ◽  
pp. 1403-1417 ◽  
Author(s):  
Andrew J. Dowdy ◽  
Graham A. Mills ◽  
Bertrand Timbal ◽  
Yang Wang
Keyword(s):  
Large Scale ◽  
Climate Models ◽  
East Coast ◽  
Global Climate ◽  
Absolute Risk ◽  
Extreme Rainfall ◽  
Global Climate Models ◽  
Extratropical Cyclone ◽  
Extratropical Cyclones ◽  
Eastern Australia

Abstract The east coast of Australia is a region of the world where a particular type of extratropical cyclone, known locally as an east coast low, frequently occurs with severe consequences such as extreme rainfall, winds, and waves. The likelihood of formation of these storms is examined using an upper-tropospheric diagnostic applied to three reanalyses and three global climate models (GCMs). Strong similarities exist among the results derived from the individual reanalyses in terms of their seasonal variability (e.g., winter maxima and summer minima) and interannual variability. Results from reanalyses indicate that the threshold value used in the diagnostic method is dependent on the spatial resolution. Results obtained when applying the diagnostic to two of the three GCMs are similar to expectations given their spatial resolutions, and produce seasonal cycles similar to those from the reanalyses. Applying the methodology to simulations from these two GCMs for both current and future climate in response to increases in greenhouse gases indicates a reduction in extratropical cyclone occurrence of about 30% from the late twentieth century to the late twenty-first century for eastern Australia. In addition to the absolute risk of formation of these extratropical cyclones, spatial climatologies of occurrence are examined for the broader region surrounding eastern Australia. The influence of large-scale modes of atmospheric and oceanic variability on the occurrence of these storms in this region is also discussed.

scholarly journals Investigating the impact of cloud-radiative feedbacks on tropical precipitation extremes

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Brian Medeiros ◽  
Amy C. Clement ◽  
James J. Benedict ◽  
Bosong Zhang
Keyword(s):  
Extreme Precipitation ◽  
Climate Models ◽  
Longwave Radiation ◽  
Extreme Rainfall ◽  
Radiative Effects ◽  
Tropical Oceans ◽  
Cloud Radiative Effects ◽  
Radiative Feedbacks ◽  
Mean Climate ◽  
The Impact

AbstractAlthough societally important, extreme precipitation is difficult to represent in climate models. This study shows one robust aspect of extreme precipitation across models: extreme precipitation over tropical oceans is strengthened through a positive feedback with cloud-radiative effects. This connection is shown for a multi-model ensemble with experiments that make clouds transparent to longwave radiation. In all cases, tropical extreme precipitation reduces without cloud-radiative effects. Qualitatively similar results are presented for one model using the cloud-locking method to remove cloud feedbacks. The reduced extreme precipitation without cloud-radiative feedbacks does not arise from changes in the mean climate. Rather, evidence is presented that cloud-radiative feedbacks enhance organization of convection and most extreme precipitation over tropical oceans occurs within organized systems. This result suggests that climate models must correctly predict cloud structure and properties, as well as capture the essence of organized convection in order to accurately represent extreme rainfall.

Using large ensembles to investigate the impacts of climate extremes

2020 ◽  
Author(s):  
Nathalie Schaller
Keyword(s):  
Extreme Events ◽  
Climate Models ◽  
Extreme Event ◽  
Climate Extremes ◽  
Heavy Precipitation ◽  
Ensemble Member ◽  
Human Influence ◽  
Weather Extremes ◽  
Large Ensembles ◽  
Thames River

<p>Large ensembles are key to investigate climate and weather extremes and their impacts, as they, by definition, rarely occur. One field that relies heavily on them is probabilistic event attribution, i.e. where one tries to quantify how human influence affects the probability of occurrence of the extreme event in question. An ensemble of over 130’000 members allowed us to quantify that human influence increased the probability of heavy precipitation by around 40% in the January 2014 floods in southern England. By using a hydrological model, we could then quantify that the probability of 30-day peak river flows of the Thames river was increased by around 20%. However, it was unclear whether the number of properties at risk in the catchment was affected. This study also showed how uncertainty increases at each step of the modelling chain and how some factors, like the characteristics of the Thames catchment in this case, might play a bigger role in assessing impacts than potentially the size of the ensemble.</p><p>Large ensembles are also useful to understand the physical mechanisms behind extreme events. In another study about the relationship between atmospheric blocking and heatwaves, we used three large ensembles from different climate models. While we found that the 2003 European heatwave and blocking conditions were well contained within the 3 ensembles’ envelope, and that the models simulated even more extreme events, the 2010 Russian event was outside the ensembles’ envelope, except for one single ensemble member.</p><p>Finally, I will present two projects, one on floods in Norway and one about the health impacts of having a heatwave combined with high air pollution, where large ensembles would be useful, but are competing with the need for high spatial resolution for computational resources.</p>

scholarly journals A personal perspective on modelling the climate system

2016 ◽  
Vol 472 (2188) ◽  
pp. 20150772 ◽  
Author(s):  
T. N. Palmer
Keyword(s):  
Climate Models ◽  
Global Climate ◽  
Climate Extremes ◽  
Climate Science ◽  
Climate System ◽  
Personal Perspective ◽  
Climate System Model ◽  
Weather And Climate ◽  
Science Community ◽  
Mathematics And Physics

Given their increasing relevance for society, I suggest that the climate science community itself does not treat the development of error-free ab initio models of the climate system with sufficient urgency. With increasing levels of difficulty, I discuss a number of proposals for speeding up such development. Firstly, I believe that climate science should make better use of the pool of post-PhD talent in mathematics and physics, for developing next-generation climate models. Secondly, I believe there is more scope for the development of modelling systems which link weather and climate prediction more seamlessly. Finally, here in Europe, I call for a new European Programme on Extreme Computing and Climate to advance our ability to simulate climate extremes, and understand the drivers of such extremes. A key goal for such a programme is the development of a 1 km global climate system model to run on the first exascale supercomputers in the early 2020s.

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