Another study has come out doing an analysis of existing surveys of papers and experts and, lo-and-behold, comes to the same position that previous studies have come to that an overwhelming number (over 95%) of experts in the field see it as manmade and human caused.
http://iopscience.iop.org/article/10.1088/1748-9326/11/4/048002
http://iopscience.iop.org/article/10.1088/1748-9326/11/4/048002
