Frank Luntz leaked in 2002 advised Republicans,
“Should the public come to believe that the scientific issues are settled, their views about global warming will change accordingly. Therefore, you need to continue to make the lack of scientific certainty a primary issue in the debate“
So what is the consensus amongst sceptical scientists of AGW?
CO2 is not a greenhouse gas
The most extreme view is CO2 is not a GHG with Joseph Postma leading this idea.
CO2 is a GHG but it has reached saturation levels and stops being a GHG
Q B Lu has come up with an almost unique explanation that it is a combination of CFCs and cosmic rays but also falls into the camp of CO2 reaching saturation levels when the greenhouse effect ceases. Others who believe in the atmospheric saturation of CO2 include Tim Ball [and those who subscribe to his pal reviewed ‘science journal’ Principia Scientific], and other contributors of Slaying the Sky Dragon– the political scientist Marc Moran [blogger of Climate Depot]
Those who deny that CO2 continues to be a GHG at higher levels merge with allies who believe:-
Temperature variations are natural/it has been hotter in the past/CO2 is plant food
Physicist Dr. William Happer and NASA Moonwalker & Geologist Dr. Harrison H. Schmitt wrote a article on this. The leading scientist with this view is Roy Spencer a meteorologist. This belief is perhaps the consensus amongst skeptics yet vague and wooly. But hey: climate is complex!
CO2 is warming the planet but it is natural- Volcanoes!
Ian Plimer a geologist reminding us that there must be lots of under water volcanoes just pumping out natural CO2.
It’s the sun- cosmic rays- it’s cooling
Unsurprisingly it is the few astrophysicists and physicists such as Henrik Svensmark who has not only published papers but done extensive research, who take this view. W Soon is another leading sceptic who says recent warming is caused by the sun. Despite evidence that cosmic rays produce almost no additional warming it is still a popular idea. Nicola Scafetta is specific that 60% of warming is the Sun- the other 40%? Geologists also seem to favour the extra-terrestrial view and promise cooling is just a few years away.
AGW is happening but it is not all CO2 but land use
this niche view is held by Roger A. Pielke who holds “that humans activities do significantly alter the heat content of the climate system, although, based on the latest understanding, the radiative effect of CO2 has contributed, at most, only about 28% to the human-caused warming up to the present. The other 72% is still a result of human activities!”
AGW is happening but sensitivity is low.
the- ‘it’s not bad’ and warming will stop around 2c or less so no need to do anything is the view taken by most sceptic climatologist including Lindzen , Robert E. Davis, John R. Christy
There are variations with Chris Landsea who doesn’t dispute AGW but questions if hurricanes will get worse and the c in cAGW. Roy Spencer on the other hand is confusing or confused accepting CO2 as a GHG in the past but questioning it now. David Legates view varies between there is no connection between temperature and human produced CO2 and the science is uncertain.
Undecided but it is a sham or scam or dodgy science
Fred Singer the scientist for hire is not clear on what he believes- he writes for thinktanks so CFCs, tobacco and CO2 are otherwise harmless and the science have been hijacked by lefty-do-gooders. One might include ‘Lord’ Monckton who accepts that CO2 has caused a small amount of warming but believes the science is a plot to bring about a New World Order.
and finally.. [no commitment on CO2 as a greenhouse gas but ] it is natural cycles
the capacity for oceans to absorb heat and release it in cycles is well known – in recent years more papers have analysed how this affects atmospheric temperatures:- the ‘it is natural cycles’ [and even it is natural terrestrial and cosmic cycles] is a growing cottage industry of science papers, pal-reviewed papers, and articles.