Well, according to Watts that is.

The term chemtrail comes from the chemtrail conspiracy theory where the claim is made that some of the contrails left by aircraft are chemical or biological agents. According to this conspiracy theory these are deliberately sprayed at high altitudes as ordered by governments. The more commonly stated reasons that I’ve heard for doing this is for mind control or population reduction.

I don’t think that I have to spend much time on telling you that this is complete and utter nonsense that’s not supported by any evidence. Just the logistics involved and the amount of people who need to be in on this make it impossible to do.

The reason I’m now talking about this is that Watts published a guest blog post by Tim Ball (archived here) in which Ball talks about the nonsense of chemtrails. With Watts saying this about it in a note he attached at the beginning:

Like with the essay Saturday about isotasy/glacial rebound being a myth, I don’t think the chemtrails idea has any merit whatsoever. Dr. Tim Ball points out more bad science – chemtrails, which are really just contrails, and which has a cult-like following much like some of the worst theories of global warming zealots – Anthony

I don’t really have a problem with him publishing something that discredits this conspiracy theory. It’s what I said that he should have done with the isostatic rebound myth guest blog post that he published:

Publishing a blog post that proposes a vast conspiracy theory that flat-out contradicts what we know and what we observe, while offering nothing that would explain this is not something you should do. It’s pseudo-science that’s just as bad as the ‘expanding earth hypothesis‘ and doesn’t deserve an open invitation to discuss its merits.

Although this time it is indeed a blog post that discredits a nonsensical conspiracy theory, and doesn’t argues for one like last time, it’s still not a very good blog post.

For one Watts compares global warming with the chemtrail conspiracy theory in his note. He doesn’t explicitly state what he sees as the “worst theories of global warming zealots”, but considering the track record of his blog there’s a good chance most of that is actual valid science.

Another reason I find this isn’t a good blog post is because of the opening statements of Ball:

One minute people say government does too much, the next they demand action to resolve problems. Environmentalists demand government stop global warming, but oppose remedial actions like spreading iron filings on the oceans to increase uptake of CO2 or spraying chemicals into the atmosphere to create clouds to block sunlight and reduce global temperatures. Both actions are wrong because they constitute geo-engineering – governments playing God. The real problem is neither governments nor opponents know what is happening, but think they do, so demand action. Doing nothing is better if you don’t understand, contrary to the false claim of the precautionary principle. Environmental issues are a war and as Aeschylus said “In war truth is the first casualty”.

There are some very real risks associated with geo-engineering which makes it not an ideal choice to say the least. We also often don’t know enough about the consequences of doing this on a planetary scale to prevent unintended consequences. Something we’re already figuring out thanks to tests with iron fertilization as shown by the paper “Iron enrichment stimulates toxic diatom production in high-nitrate, low-chlorophyll areas“:

Oceanic high-nitrate, low-chlorophyll environments have been highlighted for potential large-scale iron fertilizations to help mitigate global climate change. Controversy surrounds these initiatives, both in the degree of carbon removal and magnitude of ecosystem impacts. Previous open ocean enrichment experiments have shown that iron additions stimulate growth of the toxigenic diatom genus Pseudonitzschia. Most Pseudonitzschia species in coastal waters produce the neurotoxin domoic acid (DA), with their blooms causing detrimental marine ecosystem impacts, but oceanic Pseudonitzschia species are considered nontoxic.

What this paper says is that iron fertilisation has the potential to create toxic algae blooms from algae that normally aren’t toxic allowing them to have a negative impact on marine ecosystems. It’s unclear if this can happen, as the needed data/research isn’t available, but what we do know shows that this could be possible.

Results like this show that a lot of the science involved with geo-engineering is still unsure and there’s a lot of active research going on to figure out what is possible, how effective it is, and what can be done safely (I can recommend this blog post by David Suzuki if you want an easy to digest primer).

But most importantly is that geo-engineering cannot be used as a replacement for CO₂ emissions reductions. At best it’s a supplementary technology that can give us more time or help us with lessening the impacts. But it cannot be our first line of defence.

So it’s not exactly warranted to use that as an attack on the precautionary principle. As the precautionary principle states that “if an action or policy has a suspected risk of causing harm to the public or to the environment, in the absence of scientific consensus that the action or policy is harmful, the burden of proof that it is not harmful falls on those taking an action.”

Considering we only have one planet, we don’t know enough about the consequences, and there are hints that there could be severe consequences is enough to be cautious. It also doesn’t mean we can’t take any geo-engineering action, it just means we have to proceed with caution and weigh our options before we act.