A: Yes. Wikipedia reflects the consensus of reliable independent sources. Mainstream scientific sources are preferred when addressing topics related to science and technology. There is overwhelming consensus that the chemtrail conspiracy theory is a false and implausible narrative.
A: No. Those things are superficially similar but the core premise of the chemtrail conspiracy theory is the false idea that there is a widespread covert plot to drop chemical or biological agents from aircraft, and that long-lasting contrails are evidence of this.
Q: Why is Wikipedia suppressing the truth?
A: It isn't. Wikipedia reflects empirical fact as documented in reliable independent sources. We will include any fact that is (a) published in a reliable source and (b) demonstrably relevant and significant. Material that is excluded is not being censored or suppressed, it just fails to meet our criteria for inclusion. If your proposed content is rejected, bring more and better sources. For guidance on what constitutes a reliable source you can ask at the reliable sources noticeboard.
