The spatial extent of 20th-century warmth in the context of the past 1200 years.

Comment on "The spatial extent of 20th-century warmth in the context of the past 1200 years".

Osborn and Briffa (Reports, 10 February 2006, p. 841) identified anomalous periods of warmth or cold in the Northern Hemisphere that were synchronous across 14 temperature-sensitive proxies. However, their finding that the spatial extent of 20th-century warming is exceptional ignores the effect of proxy screening on the corresponding significance levels. After appropriate correction, the signif...

The Spatial Extent of 20 th Century Warmth in the Context of the Past 1200 Years Timothy

A Security Effective Structure for National Defense in the 21st Century

In accordance with human necessities and deep attention into security, research studies have today became an irrefutable necessity in this area. It is noted that traditional concepts of this important issue have changed, as a result of occurring various events in the past, particularly in the 20th century; so that security is no more limited to protecting human beings against individual and col...

Climate over past Millennia

[1] We review evidence for climate change over the past several millennia from instrumental and high-resolution climate ‘‘proxy’’ data sources and climate modeling studies. We focus on changes over the past 1 to 2 millennia. We assess reconstructions and modeling studies analyzing a number of different climate fields, including atmospheric circulation diagnostics, precipitation, and drought. We...

Pattern Analysis of City-Spatial Growth by Spatial Statistics (Case Study: Gorgan City)

    Urban planning has gone from the past to the present day to a greater extent based on physical factors, to the extent that the basis of urban planning plans and urban plans influenced urban development and physical spaces. It's The city is the product of complex economic and social relations and its spatial heterogeneity reflects the processes of widespread socio-economic-cultural-social ...