LA fire's toxic legacy: When wildfires turn cities into smoke

From vaporized bicycles to political extortion: The complex impacts of urban wildfire

Jan 21, 2025

Air quality of wildfire smoke

Besides the enormous physical damage, wildfires also produce a lot of air pollution, which leads to significant health impacts:

Significant exposure to urban wildfire pollution carries both acute and chronic impacts for human bodies, said Rima Habre, an environmental health scholar at the University of Southern California who lives in Los Angeles. During and immediately after wildfires and urban conflagrations, those with compromised respiratory systems, cardiovascular issues or any condition related to inflammation are likely to feel the impact. Incidences of heart attacks and strokes go up right after firestorms. Habre says more research is needed on potential long-term effects, but what’s been proven so far is harrowing. The “chronic” impacts include lower birth weights, enduring lung conditions in children, a variety of cancers in adults and increased cases of dementia. [from Inside Climate News]

But the LA fires are going to be worse than your normal wildfire, as these Bluesky posts really illustrate. First, take a look at this image:

The important thing here is that the bike is gone. Where did it go? I’m not sure vaporized is the right word; aerosolized might be better. Regardless of the word choice, the bike was turned into smoke particles and dispersed across the city.

Of course, it wasn’t just this bike. The LA fires burned buildings and everything inside them (furniture, paints, plastics and electronics), and everything on the street (cars, metal tanks, street signs, bicycles, mailboxes, power lines, garbage bins, etc.). Many of these things were also turned into smoke that people then breathed in.

Planetary scientist and Pluto-killer Mike Brown tested some of the ash:

This smoke is absolutely toxic and is going to be an enormous public health problem.

If you live in the region, here are some tips from Inside Climate News:

When venturing outside, use N95 masks, and while driving, run the AC on recirculate mode.
Protect yourself from ash exposure by wearing a hat, goggles, mask, and full-length clothing, and remove shoes before entering your home. If you have pets, use paw protection and bathe them frequently.
For indoor protection, seal any window gaps with tape and operate AC or central fans on recirculate mode. If using air purifiers, choose one with both HEPA and activated carbon filters, replacing them every few weeks, or consider building a DIY air purifier using a box fan with appropriate filters.
Maintain a rigorous indoor cleaning schedule as smoke and ash will inevitably infiltrate your space.

Wildfires and the Secretary of Energy

The Washington Post had an article about how the incoming Secretary of Energy denied the link between climate change and wildfires.

This is, of course, BS, as I explained in my last post. In fact, whether climate change had an impact or not is not even an interesting question anymore — the better question is how much of an impact did it have.

Wright cites a statistic that acres burned have been declining over time. This is classic cherry picking, a tactic where someone selectively chooses a small portion of a data set that contradicts the conclusion drawn from the entire dataset. This aims to mislead the audience by presenting a distorted picture of reality, leading them to question established facts.

When a cherry picker gives you a fact like this, the game is figuring out what they’re not telling you that more often than not obliterates the claim they’re making.

In this case, acreage does not tell the story — a more important thing to understand about today’s fires is that their fundamental nature has changed. The biggest fires are growing in intensity, leading to a number of really bad knock-on effects. For example, the biggest fires create their own weather (e.g., fire tornadoes), spread unhealthy smoke over vast swathes of the U.S., produce updrafts so intense that they can loft smoke into the stratosphere, burning places that never burned in the past (e.g., the Arctic), etc.

Wright, of course, never mentioned any of those factors that clearly make wildfires a concern to many experts.

Adaptation & extortion

One of my all-time favorite TCB posts was on how difficult dealing with the impacts of climate change is going to be:

Read it here. In that post, I wrote that climate change adaptation and recovery from disasters would be used as a weapon by politicians to extort political enemies. An example from that post: Politico reported that critical flood infrastructure funding had been held up because of New Orleans’ stance on abortion.

Well, it’s now happening in the response to the LA fires:

It’s unclear what “conditions” they want to put on any relief funds. While some policy conditions around disaster relief may be reasonable (like ensuring structures rebuilt with federal dollars are able to withstand future fires), my guess is that there will be a push to use this climate disaster as leverage to advance unrelated political agendas.

This re-emphasizes how difficult adaptation to a changing climate is going to be. As I said in that previous post, it’s going to be a nightmare. A better option, of course, is to stop dumping greenhouse gases into the atmosphere, which is causing the climate to chang. This can be done at low cost.

Table 12.12

Finally, something completely unrelated to the LA wildfires and probably only of interest to those who closely follow social media arguments over climate change.

One of the most widely misunderstood parts of the IPCC’s 6th Assessment Report is Table 12.12. It summarizes whether various trends in Climate Impact Drivers (abbreviated CIDs) have already emerged or will emerge in the future.

For example, if you look at Fire Weather, you see the cells are all white, suggesting that no signal will emerge even by 2100 in the RCP8.5 scenario.

Climate deniers use this to suggest that humans have not made fire weather worse. However, if you look at Table 11.1 of the same report, it says that human influence is already increasing fire weather occurrence (medium confidence). Ditto for many of the other impacts that, according to Table 12.12, have not yet “emerged”.

So what’s going on? Why is there a disconnect between these different parts of the report.

The answer is that the emergence of CIDs is quite different from observations of a trend. CIDs start with trends but then link in the connections to societal and ecological impacts. In other words, CIDs are explicitly tied to demonstrable impacts on human and natural systems.

In addition, “emergence” refers to a very large change in the system. I asked Alex Ruane, who wrote the paper on CIDs about this, and this is what he said:

That table [12.12] has certainly caused some confusion. The key thing to note there is that the “Emergence” metric is a very high bar for change where the average future year would be considered extreme in the reference (historical) climate. It is also looking for emergence across broad scales rather than a specific region, which again makes it an extreme metric of noteworthy climate change.
The assessment of whether we observe or project a signal of change can be seen in the regional tables of Chapter 12, which reflect analysis in CH12 as well as analyses in the other IPCC chapters (e.g., extremes for heavy precipitation are in CH11). There you can see that many regions show strong signals in heavy precipitation and pluvial flooding, and in CH11 you can also see clear detection and attribution examples for this variable (as further summarized in the IPCC SPM).

Thus, deniers are making claims about Table 12.12 that the authors clearly are not intending it to mean. Despite what the table says, we can be certain that humans affecting many of these systems.

So next time someone brings up Table 12.12, tell them to read this section.

The Climate Brink

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