The chemtrail folks are pretty garden variety conspiracy theorists for the most part. I've bumped into a number of them and they don't even seem that bothered about it. They're both forms of climate change denial.My elaboration:
Of course, some high-profile "geo-engineering" schemes have involved batty notions of fleets of aircraft replicating volcano eruptions to promote cooling (what could possibly go wrong?) or aerosols to turn cloudbanks into mirrors reflecting the away sunlight (what could possibly go wrong?) and so on, and, of course, there might be a DARPA white paper here and there blueskying (no pun intended) along these line as there is a DARPA white paper blueskying about almost every damn fool thing imaginable, and of course no doubt you can find a photogenic cranky midwestern zillionaire willing to blow a million bucks using cropdusters to realize his fever-dream of spreading uplifting nootropic substances over America's malls to save the white race or some such. America has, after all, crazily skewed distributions of wealth as well as of sense and such things happen here.
But when the chemtrail conspiracists whomp up their diabolical visions from this scattered breadcrumb trail they are tapping into the same reservoirs that Bircher anti-fluoridation panics do (actually, there were chemtrail panics in the early 60s predating my birth that drew not only their ideas but their partisans directly from the anti-fluoridation folks) but which also find UFOs in skies empty of anything but cute curious clouds -- that is to say, there is more to contrail dissipation than is dreamed of in their philosophy.
The hostility to the very idea of good or representative governance yields an endless and unfalsifiable harvest for such conspiracy thinking, usually to the cost of necessary scrutiny and useful criticism of actual government abuses: very much in line with 9/11 "truthers" for example, who distracted attention from the fraud of pre-emption based on the pretext of WMD, the incompetence and warcrimes of the prosecution of the war and occupation, and the authoritarian measures enabled by the paranoia in part symptomized and exacerbated by the truthers themselves. Needless to say, the "chemsters" now have their youtube documentaries with millions of hits and tweets and likes as the "Loose Change" truther crowd did before.
I do agree that this amounts to climate change denialism but I think we should be clear that what is most interesting here is not the blunt denial of a factual phenomenon and its stakes according to an enormous consensus of relevant scientists, but a denial about secular social democratic governance. The geo-engineers and chemtrail conspiracy would both circumvent education, organization, and reform alive to constituted accountable governance: the geo-engineers want to use the emergency to obtain a free pass to continued profit taking, the chemsters want to retreat into survivalist isolation.
The pattern here is actually very familiar to the student of futurology -- it replicates the ideological polarities of transhumanists and bioconservatives, each committed to a fantastic construction of "the natural" with which one dis-identifies and the other identifies, yielding under-critical technophilia in one and then under-critical technophobia in the other.
This reminds us that climate change denialism itself is not most essentially a denial of facts so much as the denial of the secular-democratic forms through which scientists arrive at consensus as to what constitutes facts (results, publications, tests, deliberation that weaves novelty into the body of knowledge and into educable forms) and of the secular-democratic forms through which citizens (scientists and non-scientists alike) hold policy-makers, representatives, and scientists accountable for their role in public decision making beholden to consensus science in a mass-mediated, p2p-mediated, at least notionally representative governmental formation.