Extreme climatic events and their evolution under changing climatic conditions

This short introductory paper illustrates some key issues concerning extremes by focusing on daily temperature extremes defined using quantiles and threshold exceedances. The examples include both a low- and a high-elevation site in the Swiss Alps where long records of homogenous daily data are readily available. The analysis of extremes highlights several features, some of them taken from the 2003 heat wave that affected Europe, in particular significant changes in the trends of quantiles in the course of the 20th century, differences in the altitudinal behavior of maximum or minimum temperatures, and close links between means and the extreme quantiles of daily temperatures.[1]


Is There a Relationship Between Ground and Climatic Conditions and Injuries in Football?

Most soccer, rugby union, rugby league, American football, Australian football and Gaelic football competitions over the world are played on natural grass over seasons that commence in the early autumn (fall) and extend through winter. Injury surveillance in these competitions has usually reported high rates of injury to the lower limb and an increased incidence of injuries early in the season. This ‘early-season’ bias has not usually been reported in summer football competitions, or in sports played indoors, such as basketball. Although easily compared rates have not often been published there has also been a reported trend towards a greater injury incidence in football played in warmer and/or drier conditions. Injury incidence in American football played on artificial turf has often been reported to be higher than in games played on natural grass. This review concludes that the most plausible explanation for all of these reported findings involves variations in playing surface characteristics. Shoe-surface traction for the average player is the specific relevant variable that is most likely to correlate with injury incidence in a given game of football. Shoe-surface traction will usually have a positive correlation with ground hardness, dryness, grass cover and root density, length of cleats on player boots and relative speed of the game. It is possible that measures to reduce shoe-surface traction, such as, ground watering and softening, play during the winter months, use of natural grasses such as perennial ryegrass (Lolium perenne L.) and player use of boots with shorter cleats, would all reduce the risk of football injuries. The most pronounced protective effect is likely to be on injuries to the lower limb of a noncontact nature, including anterior cruciate ligament injuries. Intervention studies should be performed, both using randomised and historical controls.[2]


Invited review: Influence of climatic conditions on the development, performance, and health of calves

The objective of this review is to provide the reader with an overview of thermoregulatory mechanisms and the influence of climatic conditions in different housing systems on the development, performance, and health of calves. Thermic stress is observed in association with extreme temperatures and large temperature variations, but other variables such as relative humidity and wind speed can also contribute to thermic stress. Thermoregulation in calves is similar to that in adult cattle, but especially dystocial calves are more prone to heat loss. Heat or cold stress results in direct economic losses because of increased calf mortality and morbidity, as well as indirect costs caused by reduced weight gain, performance, and long-term survival. The climatic conditions in a variety of housing systems, associated health problems, and strategies to mitigate thermic stress are discussed in this review. The goal of housing is to alleviate the effect of climate on calves and provide a microclimate. Adequate ventilation with fresh air is essential to reduce respiratory disease. Common practices such as raising calves in individual outdoor enclosures have been challenged lately. Recent research seeks to evaluate the suitability of group housing under practical, economic, and animal welfare considerations. Limited results for reducing thermic stress can be achieved by simple measures such as shades or shelter, but additional heat or cold stress relieving strategies can be required depending on the housing system.[3]


Nitrate Nitrogen in Surface Waters as Influenced by Climatic Conditions and Agricultural Practices

Subsurface tile drainage from row-crop agricultural production systems has been identified as a major source of nitrate entering surface waters in the Mississippi River basin. Noncontrollable factors such as precipitation and mineralization of soil organic matter have a tremendous effect on drainage losses, nitrate concentrations, and nitrate loadings in subsurface drainage water. Cropping system and nutrient management inputs are controllable factors that have a varying influence on nitrate losses. Row crops leak substantially greater amounts of nitrate compared with perennial crops; however, satisfactory economic return with many perennials is an obstacle at present. Improving N management by applying the correct rate of N at the optimum time and giving proper credits to previous legume crops and animal manure applications will also lead to reduced nitrate losses. Nitrate losses have been shown to be minimally affected by tillage systems compared with N management practices. Scientists and policymakers must understand these factors as they develop educational materials and environmental guidelines for reducing nitrate losses to surface waters.[4]


Geomorphic responses to climatic change

The primary focus of this book is the response of landscapes to Pleistocene and Holocene climatic changes. During the past 40 ky the global climate has varied from full-glacial to interglacial. Global temperatures decreased between 40 and 20 ka culminating in full-glacial climatic conditions at 20 ka. This resulted in a sea level decline of 130 m. Only 8 to 14 ky later the global temperature had reversed itself and the climate was the warmest of the past 120 ky. These dramatic changes in climate imposed significant controls on fluvial systems and impacted land forms and whole landscapes worldwide. Chapter 1, Conceptual Models for Changing landscapes, presents numerous concepts related to erosional and depositional processes controlling landscape development. Each of the next four chapters of the book, 2, 3, 4, and 5, examine different aspects of climatic change on fluvial systems. The conceptual models are used to analyze landscape response in four different climatic and geologic settings. In each setting the present and past climatic conditions, the climatically induced changes in vegetation and soil development, and geochronology are considered in assessing the influence of climatic changes on geomorphic processes.[5]


Reference

[1] Beniston, M. and Stephenson, D.B., 2004. Extreme climatic events and their evolution under changing climatic conditions. Global and planetary change, 44(1-4), pp.1-9.

[2] Orchard, J., 2002. Is there a relationship between ground and climatic conditions and injuries in football?. Sports medicine, 32(7), pp.419-432.

[3] Roland, L., Drillich, M., Klein-Jöbstl, D. and Iwersen, M., 2016. Invited review: Influence of climatic conditions on the development, performance, and health of calves. Journal of dairy science, 99(4), pp.2438-2452.

[4] Randall, G.W. and Mulla, D.J., 2001. Nitrate nitrogen in surface waters as influenced by climatic conditions and agricultural practices. Journal of environmental quality, 30(2), pp.337-344.

[5] Bull, W.B., 1991. Geomorphic responses to climatic change.