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Comment by cm2187 | Hacker News Reader

Would be curious to compare how much CO2 has been emitted as a result of these fires to California’s annual CO2 savings by going for renewable energy.

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That might be interesting from a purely educational point of view but it is of little practical relevance.

Trees burning in wild fires release CO2 that was captured in the last couple of decades by the tree in the process of growing. Burning fossil fuels releases CO2 which was captured millennia ago and buried deep underground.

It's roughly the same as why melting icebergs cause sea levels to rise but rain will not.

It's of little relevance if the trees regrow. There are some signs these big fires may permanently damage the ecosystems in ways that prevent that.

https://www.cbc.ca/news/technology/forests-wildfires-1.44449...

Prehistoric fires are believed to have been much larger than the current ones. In California for example, this year's historic 3.4 million acres fall below estimates for average fire area, although I don't know if California is just unusually fire-prone.

Sources/readings: https://www.sierraforestlegacy.org/Resources/Conservation/Fi... https://www.waterboards.ca.gov/water_issues/programs/tmdl/re...

> Prehistoric fires are believed to have been much larger than the current ones.

Sure, but humans weren't a) burning a hundred million years worth of fossil fuels and b) siphoning off all the water in the area to grow almonds at that time.

Fire size in acres isn't the only variable, either; the article I linked states "The fire was so intense in some places that it burned up all organic matter needed to help the soil retain nutrients and moisture required for trees to grow."

I'm not sure how almonds came to be the go-to example of waste in California agriculture, but they're a bad one.

- Almonds can't be grown in most places, California is uniquely well-suited to it.

- California almond-growing practices are (much) more wasteful than they need to be. Israeli almond farmers can grow an almond with 1/20th the water used in California; the main innovation is irrigating into a three-foot-deep pipe, instead of spraying water on the surface, where most of it evaporates. Switching California's practices to match would be a relatively simple matter of insisting upon it.

- Almond farming uses an insignificant, single-digit amount of California's agricultural water budget. 45% of California water is splurged on alfalfa growing for fodder. Which can be grown anywhere, is a bad match for the climate and water resources, and is the place where any rational attempt to bring California agriculture into alignment with reality should begin.

So you're saying if we just calm down with the damn almonds we'll be fine?

It would help people understand the misguided policies that have been in effect, which prevent any meaningful reduction in fuel via cutting or burning -- policies meant to preserve the environment, but instead actually harm it.

"Preserving the environment" is rather a misdirection.

Initially, fire suppression's "10 a.m. rule" was the result of forest industry advocacy. More recent burn opposition comes from real-estate interests --- homeowners, but also banks, mortgage holders, and insurance companies --- seeking to preserve asset values. Periods are roughly the 1930s for the first and 1970s/80s onward for the latter.

Actual environmentalists (and many foresters) have advocated more though controlled and smaller burns for decades. I've travelled through the Western US numerous times over the past 30 years, and the role and scale of fire has long been evident. My trips have included travelling through recently-burnt landscapes, and several which burned within a few years of my passing through.

I had a long conversation with a forester on a road trip in the mid-aughts that was particularly memorable, and on which I've had frequent cause to reflect on since.

See, e.g.,

'Fire is medicine': the tribes burning California forests to save them (2019) https://www.theguardian.com/us-news/2019/nov/21/wildfire-pre...

Barriers and enablers for prescribed burns for wildfire management in California https://www.nature.com/articles/s41893-019-0451-7

FYI melting iceberg do not cause sea levels to rise, but glacier do. An ice cube melting in your glass water do not rises the level.

Yes, fair point. I was speaking inexactly. I of course meant glaciers or perhaps icebergs which break off of glaciers.

I don't think that this is technically true, since icebergs are made from fresh water and they melt in the salt water of the ocean. Fresh water is less dense, so it will take up a larger volume than that of salt water.

Where does the additional density come from that wasn't there already when the iceberg was floating?

The amount of salt water displaced by the fresh water ice is equal to its weight, but the melted fresh water will take up a slightly larger volume than the displaced salt water. It is small, but calculable.

From what I remember reading, if all of the floating sea ice on the globe were to melt right now, sea levels would rise by about 5 centimeters.

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201...

Yes you are right but this is not enough to have a meaningful impact.

the thermal expansion coefficient of liquid water explains the rise

That would be an effect of ocean warming. The melting itself occurs at a nearly constant temperature and is correlated with, but not causative of, the ocean warming.

But, perhaps you're trying to point out that the thermal expansion of the oceans has a greater impact on sea level rises than the correlated problem of glacier melting.

It could be relevant if a bunch of different wildfires happen around the same time worldwide. If they bring the global average temperature above some tipping point and result in the melting of permafrost and release of large amounts of methane, that could cause the runaway greenhouse effect to occur much earlier than previously forecast.

I'm afraid if that was the case the world is so delicately balanced that we are already fubar.

> we are already fubar

Nobody's shown any convincing evidence that this isn't the case. We've been tracking worse-than-worst-case-predictions for a while https://www.theguardian.com/environment/2020/jun/13/climate-...

Well it does matter in the sense of how bad policy can annihilate the benefits of good policy

Not to mention the fact that California is still emitting far more CO2 then it should in order to keep the climate disaster at bay.

Any comparison between current carbon savings and emissions of natural disaster would be an exercise in irrelevance.

> in the last couple of decades by the tree in the process of growing [...]

Isn't most biomass from trees that are centuries old?

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