To: Maurice Winn who wrote (148159 ) 4/29/2019 9:18:24 PM From: Snowshoe Read Replies (2) | Respond to of 217795 re "The active layer can be deduced from the size of the trees as they need deep roots to not fall over, and to get at the water they need in summer." Trees growing in a thin active layer over permafrost have shallow plate-like root systems, not deep tap roots. re "What matters is air temperature. That has been monitored for 100 years fairly well and very well for 40 years and pretty good for a few hundred years with less precision, but well enough to know about medieval warming, Mongol success, Greenland success, Maori migration to the freezing south (not so freezing in warmer climate). Over the last 50 years there actually has not been the expected tropospheric heating that the simplistic Greenhouse Effect so-called Settled Science predicted." So what is causing the rapid temperature rise in the arctic permafrost? Could it be absorbing that excess heat out of the troposphere?North Slope permafrost thawing sooner than expected phys.org "The temperature of permafrost is rapidly changing," said Vladimir Romanovsky, head of the Permafrost Laboratory at the University of Alaska Fairbanks Geophysical Institute. "For the last 30 years, the mean annual ground temperature at the top of permafrost on the North Slope has been rising," Romanovsky said. The mean annual ground temperature—an average of all of the years' highs and lows at the Deadhorse research site—was 17.6 degrees Fahrenheit (minus 8 degrees Celsius) in 1988, and now it's 28.5 F (minus 2 C). Researchers expect the average annual ground temperature to reach 32 F (0 C), the melting point of ice, in many areas. "We believe this will be before 2100 at many locations within the North Slope," Romanovsky said.