Observations contradict claim 2007 Arctic sea ice extent was due to greenhouse gases

A new paper published in Earth Interactions finds that satellite observations show the low Arctic sea ice extent of 2007 was associated with a large increase in solar surface radiation and a decrease in infrared radiation from greenhouse gases from 2006 and 2007. Thus, the observations contradict AGW alarmist claims that the 2007 low Arctic sea ice extent was related to man-made greenhouse gases, and instead suggests natural factors such as solar surface radiation [modulated by clouds] were responsible.

Other natural phenomena including ocean oscillations, Arctic cloud cover, winds and storms, and solar activity have been linked to changes in Arctic sea ice extent, not man-made CO2. 

Since the 2007 low, Arctic sea ice has greatly recovered to the second highest extent in a decade, and the highest in nine years, again indicating natural variability, not CO2, is the control knob of Arctic sea ice. At the unmentionable South Pole, Antarctic sea ice extents have blown through the highest recorded levels ever for each of the past 5 years, again indicating natural variability, not CO2, is the control knob of polar sea ice.

The authors also find major problems in the "reanalysis" data of downwelling summertime shortwave [solar] radiation and downwelling summertime longwave radiation [IR from greenhouse gases] in comparison to the actual satellite observations, finding,

"large spreads, particularly for downwelling shortwave radiation. In many cases, the differences in significant trends between the 5 reanalysis products are comparable to the estimated trend within a particular product. These discrepancies make it difficult to establish a consensus on likely changes occurring in the Arctic solely based on results from reanalyses fields." 

and that comparing "observations against these reanalysis products present an ambiguity.
Thus, agreement within reanalysis fields needs to be further checked against observations to assess possible biases common to all [reanalysis] products."

In other words, believe the direct satellite observations, but not the data reanalysis "products." And the direct satellite observations show the opposite of what AGW alarmists claim is responsible for Arctic sea ice changes [which is a decrease, not increase of downwelling IR associated with the 2007 low].

Earth Interactions 2014 ; e-View

doi: http://dx.doi.org/10.1175/EI-D-14-0012.1

An Evaluation of Surface Atmospheric Changes over the Arctic Ocean for 2000-09 Using Recent Reanalyses

Ayan H. Chaudhuri

Atmospheric and Environmental Research Inc, 131 Hartwell Ave, Lexington MA 02421. Email:achaudhu@aer.com; Phone: 781-761-2382

Rui M. Ponte

Atmospheric and Environmental Research Inc, 131 Hartwell Ave, Lexington MA 02421. Email: rponte@aer.com; Phone: 781-761-2231

Abstract

We examine 5 recent reanalysis products (CFSR, MERRA, JRA-25, ERA-Interim and ASR) for (1) trends in near-surface radiation fluxes, air temperature and humidity, which are important indicators of changes within the Arctic Ocean and also influence sea-ice and ocean conditions, and (2) fidelity of these atmospheric fields and effects for an extreme event, namely the 2007 ice retreat. An analysis of trends over the Arctic for the past decade (2000-2009) shows that reanalysis solutions have large spreads, particularly for downwelling shortwave radiation. In many cases, the differences in significant trends between the 5 reanalysis products are comparable to the estimated trend within a particular product. These discrepancies make it difficult to establish a consensus on likely changes occurring in the Arctic solely based on results from reanalyses fields. Regarding the 2007 ice retreat event, comparisons with remotely-sensed estimates of downwelling radiation observations against these reanalysis products present an ambiguity. Remotely-sensed observations from a study cited herewith suggest a large increase in downwelling summertime shortwave [solar] radiation and decrease in downwelling summertime longwave [greenhouse gas] radiation from 2006 and 2007. On the contrary, the reanalysis products show only small gains in summertime shortwave radiation, if any, however all the products show increases in downwelling longwave radiation. Thus, agreement within reanalysis fields needs to be further checked against observations to assess possible biases common to all [reanalysis] products.