Thursday, January 30, 2020

This is How the Noose Will Tighten

"After California wildfires, insurance companies drop some homeowner policies," Yale Climate Connections, Jan 30, 2020.


David in Cal said...

Insurance companies need to make a profit and not go bankrupt. That means charging a premium greater than expenses plus expected losses. And, not having so much at risk that a single event could bankrupt the company. That's why California insurance companies raised rates and dropped some business.

I am concerned about the article's blaming global warming for the increase in wildfires. While global warming may have some effect, I believe the more important factor is change in land management. I hope the experts are looking at steps they can directly do to reduce these awful fires.


David Appell said...

David, thanks for your insights. Most of what I read -- not systematic, to be sure -- puts some blame on global warming. It seems to me that since warmer temperatures mean a higher evaporation rate, hence drier trees and vegetation, it will also play a role in making a potential fire worse.

Also, here's something I don't get. When people talk about better land and forest management, what exactly are they thinking of? It often seems a euphemism for logging.... I've read at least one article that says forest thinning causes as many fires as it prevents, with all the machines moving around with the potential for fires and accidents. But how can there be enough forest thinning to make much of a difference? Some of the recent forest fires have been huge -- can a forest really be thinned over that large an area? Or is it to be done on the outskirts towns and homes? The other problem with systematic thinning is that the forest needs all that brush lying around if it is to flourish. So do the animals, insects, bugs etc that live there, which are in turn important for the forest to thrive. So I'm confused. Do you have any thoughts on these?

Layzej said...

One thing worth considering is that there is an exponential relationship between fuel aridity and the wildfire area. This means that the next degree of warming will be much worse than the previous in terms of wildfires.

I'm not sure how much it would cost to use land management to mitigate the increase in wildfires that global warming is causing.

We should expect that the cost will be exponentially higher with each degree of warming.

David Appell said...

Thanks for that. Is the exponential relationship basically due to the Clausius-Claperyon equation, i.e. the fact that warmer air holds water vapor, and that water vapor comes out of soil & vegetation? The saturation pressure of water vapor goes up 7% (an exponential) for every 1 C of warming. (All else being equal, etc.)

I guess I should read the PNAS paper.

David Appell said...

Here's that paper:

Impact of anthropogenic climate change on wildfire across western US forests
John T. Abatzoglou and A. Park Williams
PNAS October 18, 2016 113 (42) 11770-11775.

Ned said...

I think talk about "better land and forest management" is a mix of valid and entirely bogus ideas, but when used in this context (as a foil to talking about the very real increase in fire danger from climate change) it's purely intended as a distraction.

In some regions, "forest management" has contributed to the problem by suppressing smaller fires in the 20th century, resulting in unnaturally high fuel loads. Also, the expansion of low-density housing ("rural sprawl") into flammable forested areas both increases the risk of fires (more people x more time) and the need for fire suppression (even small fires can't be permitted in a forest full of suburban houses).

So if "bad land management" and "bad forest management" have contributed to the problem in the past, then surely "better management" seems like an answer. But in some areas it's not clear that there is any obvious "better management" that's cost effective and socially acceptable, as you point out.

And then so much of the claims about "better forest management" turns out to just be uninformed garbage like Trump's "raking the forests" nonsense. Most of the people who will aggressively lecture you that "all these fires aren't caused by climate change, they're caused by bad management" literally know nothing at all about forest ecology and management.

It's just more of that thing where they need to have an alternative box they can check for every single aspect of climate science. Whether the alternative makes sense doesn't matter, it just needs to be something they can recite robotically when the topic of AGW comes up.