Warming, thawing and decrease in areal extent of terrain underlain by permafrost are expected in response to climatic change in the 21st century (Sazonova et al., 2004; Euskirchen et al., 2006; Lemke et al., 2007). (ipcc.ch)
The National Ignition Facility has been used to compress deuterium - tritium to an average areal density of ~ 1.0 ± 0.1 g cm -LRB--2), which is 67 % of the ignition requirement. (semanticscholar.org)
Two say «PRC - derived temp index,» which are listed as «areal average» and «Estimates.» (climateaudit.org)