scholarly journals Global Climate Change as a Driver of Bottom-Up and Top-Down Factors in Agricultural Landscapes and the Fate of Host-Parasitoid Interactions

Author(s):  
Frank Chidawanyika ◽  
Pride Mudavanhu ◽  
Casper Nyamukondiwa
Author(s):  
Jayne F. Knott ◽  
Jo E. Sias ◽  
Eshan V. Dave ◽  
Jennifer M. Jacobs

Pavements are vulnerable to reduced life with climate-change-induced temperature rise. Greenhouse gas emissions have caused an increase in global temperatures since the mid-20th century and the warming is projected to accelerate. Many studies have characterized this risk with a top-down approach in which climate-change scenarios are chosen and applied to predict pavement-life reduction. This approach is useful in identifying possible pavement futures but may miss short-term or seasonal pavement-response trends that are essential for adaptation planning. A bottom-up approach focuses on a pavement’s response to incremental temperature change resulting in a more complete understanding of temperature-induced pavement damage. In this study, a hybrid bottom-up/top-down approach was used to quantify the impact of changing pavement seasons and temperatures on pavement life with incremental temperature rise from 0 to 5°C at a site in coastal New Hampshire. Changes in season length, seasonal average temperatures, and temperature-dependent resilient modulus were used in layered-elastic analysis to simulate the pavement’s response to temperature rise. Projected temperature rise from downscaled global climate models was then superimposed on the results to determine the timing of the effects. The winter pavement season is projected to end by mid-century, replaced by a lengthening fall season. Seasonal pavement damage, currently dominated by the late spring and summer seasons, is projected to be distributed more evenly throughout the year as temperatures rise. A 7% to 32% increase in the asphalt-layer thickness is recommended to protect the base and subgrade with rising temperatures from early century to late-mid-century.


2018 ◽  
pp. 889
Author(s):  
Jason MacLean

Global climate change is at the point where politics as usual is not sufficient to combat it. The author argues that a new conceptualization of constitutionalism and federalism will be required to respond to this change. What the author calls federalism 3.0 will be a bottom-up approach to politics, where individuals are empowered by governments and institutions to shape climate policy. This bottom-up approach is encapsulated in the Paris Climate Change Agreement. Canadian Prime Minister Justin Trudeau has publicly declared Canada’s commitment to climate leadership through mobilizing all elements of Canadian society. However, the author argues Trudeau’s policies to date are merely an example of formalistic, check-the-box constitutionalism, rather than substantive, federalism 3.0.


2009 ◽  
Author(s):  
Marci Culley ◽  
Holly Angelique ◽  
Courte Voorhees ◽  
Brian John Bishop ◽  
Peta Louise Dzidic ◽  
...  

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