The majority of scientists agree that global warming is real, human caused, and is a major threat.

The science says...

The 97% consensus has been independently confirmed by a number of different approaches and lines of evidence.

Communicating the expert consensus is very important in terms of increasing public awareness of human-caused climate change and support for climate solutions.  Thus it's perhaps not surprising that Cook et al. (2013) and its 97% consensus result have been the subject of extensive denial among the usual climate contrarian suspects.  After all, the fossil fuel industry, right-wing think tanks, and climate contrarians have been engaged in a disinformation campaign regarding the expert climate consensus for over two decades.  For example, Western Fuels Association conducted a half-million dollar campaign in 1991 designed to ‘reposition global warming as theory (not fact).’

The 97% Consensus is a Robust Result

Nevertheless, the existence of the expert consensus on human-caused global warming is a reality, as is clear from an examination of the full body of evidence.  For example, Naomi Oreskes found no rejections of the consensus in a survey of 928 abstracts performed in 2004.  Doran & Zimmerman (2009) found a 97% consensus among scientists actively publishing climate research.  Anderegg et al. (2010) reviewed publicly signed declarations supporting or rejecting human-caused global warming, and again found over 97% consensus among climate experts.  Cook et al. (2013) found the same 97% result through a survey of over 12,000 climate abstracts from peer-reviewed journals, as well as from over 2,000 scientist author self-ratings, among abstracts and papers taking a position on the causes of global warming.

[skepticalscience.com]