The study also shows that an additional summertime warming factor of 2.2 °F is needed to explain the unusually strong melting observed since the 1990s. (environmentalresearchweb.org)
Would we really want several warming factors (solar, volcanism, etc), including AGW, to piggy - back on each other & send us into really dire straits? (realclimate.org)
Result: NS 2) «In reviewing the results, the IPCC report concluded: «No climate model using natural forcings [i.e., natural warming factors] alone has reproduced the observed global warming trend in the second half of the twentieth century. (realclimate.org)