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> Except forest fires do not produce CO2. They release carbon that has been temporarily stored in trees and is part of the carbon cycle. I hope you are kidding

> Except forest fires do not produce CO2. They release carbon that has been temporarily stored in trees and is part of the carbon cycle. I hope you are kidding. The planet has had multiple cycles of atmospheric CO2 increases and decreases over millions of years. We have very accurate data to cover 800,000 years, where the range was between, roughly, 200 and 300 ppm. The question is: How did CO2 increase when humanity was pretty much insignificant and not burning fossil fuels? How did that happen? The answer is simple: Massive, continental scale forest fires. Without modern fire fighting and mitigation technologies these fires burned for very long periods of time and razed areas the size of entire modern cities. The average 100 ppm increase took about 100K years. Nothing other than fires could cause this change. Fires over a very long period of time. The other question is: How did atmospheric CO2 concentration decrease? After all, we were not around to "save the planet" with technology. Also simple: Rain, hurricanes, cyclones, weather and vegetation regrowth over 100K years. That's how long it took the natural planetary engine to react to a 100 ppm change in atmospheric CO2 and revert it. Next question: How did humans add another 100 ppm+ in such a short period of time? Because we burned more forests faster than nature could have ever done on its own. Except we did this by burning oil, petroleum. One way to look at petroleum is that it is a highly concentrated form of plant and other biomass materials turned into goo we can easily burn. And so, by burning it, we engaged in the equivalent of burning entire forests on a daily, monthly or annual basis for the last several hundred years. As population grew, the more we burned. And here we are. Forest fires absolutely produce CO2. That has been the cased for millions of years. If it makes your more comfortable to say they release CO2, so be it. That's fine. The net effect is the same: CO2 accumulates in the atmosphere and contributes to global warming. Same thing cars do. The greater point is a dark one, and one most people are not ready to accept: There isn't a thing we can do about it. It's a planetary-scale problem that will take in the order of tens of thousands of years to affect. We can't do it. EDIT: One more question we should ask: How many trees (or plants) went into creating one unit of petroleum? https://www.eurekalert.org/news-releases/654287 https://www.eurekalert.org/news-releases/654287 From the article: "Can you imagine loading 40 acres worth of wheat – stalks, roots and all – into the tank of your car or SUV every 20 miles?" asks ecologist Jeff Dukes, whose study will be published in the November issue of the Journal Climatic Change. Here's the full paper: https://core.ac.uk/download/pdf/5212176.pdf https://core.ac.uk/download/pdf/5212176.pdf

defrost 4y ago
Weird .. and here I was naively thinking the dominant process for past increases in C02 prior to the Pleistocene+Holocene was magmatic processes and could be demonstrated by examining the isotopic fractionation between inorganic and organic carbon.
- robomartin 4y ago
  Not a single process. Nothing has a single explanation. These are planetary scale effects. There's a lot we don't know and we will never know.
  - defrost 4y ago
    "Dominant process" implies other processes .. it's difficult to know all the details of any such complex transforms .. it's less difficult to pick out the major contributions by scale from the signature after traces. You're correct that fossil fuels are buried sunlight from many many millions of years ago and bringing them to the surface now is the major factor contributing to our current swing against the norms of the past 800K years re: climate. With forrest fires, unless there is burial and no regrowth, we are very much looking at the surface carbon cycle; trees grow (capturing carbon), burn (releasing carbon), cycle, repeat. It takes a major expansion or a major reduction (significant in terms of Earths surface) of forrests to alter the over all long term balance; forrests to peat bogs, peat bogs drying out and burning is another big shift on the accounts .. but again these are the "near surface" accounts of organic carbon. These differ (by isotope) from deep carbon bought up to the surfce (from FF) and from magma carbon.
    - robomartin 4y ago
      > With forrest fires, unless there is burial and no regrowth, we are very much looking at the surface carbon cycle; trees grow (capturing carbon), burn (releasing carbon), cycle, repeat. The point is that this cycle isn't anywhere close to 100% efficient and takes orders of magnitude more time to reverse than the time it took to burn it. On top of that, atmospheric CO2 hangs around in the atmosphere and is incredibly difficult and grotesquely inefficient to remove. As I mention in another comment, here in SoCal we recently had a fire --one of many-- that took out over 5000 acres in a matter of two to four days. The recovery of that land, the regrowth, will likely take twenty years (how long does a mature tree take to grow?). The CO2 released in that short event will take orders of magnitude more time to be re-captured. It doesn't hang around over the burn area waiting to be absorbed. The natural rate of change for atmospheric CO2 concentration reduction is in the order of 1 ppm per 1000 years. That figure comes out of ice core sample data, which is very accurate. Anything that claims a significant improvement to that rate of change must come with equally significant proof. We have people claiming we can drop atmospheric CO2 by 100 ppm in twenty years. Put a different way, they are saying they can do what nature does in 100K years in just 20. This is a rate of change with a slope 5000 times faster than the natural rate...and nobody seems interested in questioning it. It's one thing to achieve this in a lab experiment. Quite another at a planetary scale. And so, my point, with regards to forest fires, is two fold: The net effect is the same, meaning, CO2 in the atmosphere. Second, the CO2 generated per unit time isn't recovered at the same rate. It is recovered orders of magnitude slower. Therefore, forest fires are likely just as damaging (in terms of atmospheric CO2 accumulation) as burning any other fuel.

defrost 4y ago

Weird .. and here I was naively thinking the dominant process for past increases in C02 prior to the Pleistocene+Holocene was magmatic processes and could be demonstrated by examining the isotopic fractionation between inorganic and organic carbon.

robomartin 4y ago
Not a single process. Nothing has a single explanation. These are planetary scale effects. There's a lot we don't know and we will never know.
- defrost 4y ago
  "Dominant process" implies other processes .. it's difficult to know all the details of any such complex transforms .. it's less difficult to pick out the major contributions by scale from the signature after traces. You're correct that fossil fuels are buried sunlight from many many millions of years ago and bringing them to the surface now is the major factor contributing to our current swing against the norms of the past 800K years re: climate. With forrest fires, unless there is burial and no regrowth, we are very much looking at the surface carbon cycle; trees grow (capturing carbon), burn (releasing carbon), cycle, repeat. It takes a major expansion or a major reduction (significant in terms of Earths surface) of forrests to alter the over all long term balance; forrests to peat bogs, peat bogs drying out and burning is another big shift on the accounts .. but again these are the "near surface" accounts of organic carbon. These differ (by isotope) from deep carbon bought up to the surfce (from FF) and from magma carbon.
  - robomartin 4y ago
    > With forrest fires, unless there is burial and no regrowth, we are very much looking at the surface carbon cycle; trees grow (capturing carbon), burn (releasing carbon), cycle, repeat. The point is that this cycle isn't anywhere close to 100% efficient and takes orders of magnitude more time to reverse than the time it took to burn it. On top of that, atmospheric CO2 hangs around in the atmosphere and is incredibly difficult and grotesquely inefficient to remove. As I mention in another comment, here in SoCal we recently had a fire --one of many-- that took out over 5000 acres in a matter of two to four days. The recovery of that land, the regrowth, will likely take twenty years (how long does a mature tree take to grow?). The CO2 released in that short event will take orders of magnitude more time to be re-captured. It doesn't hang around over the burn area waiting to be absorbed. The natural rate of change for atmospheric CO2 concentration reduction is in the order of 1 ppm per 1000 years. That figure comes out of ice core sample data, which is very accurate. Anything that claims a significant improvement to that rate of change must come with equally significant proof. We have people claiming we can drop atmospheric CO2 by 100 ppm in twenty years. Put a different way, they are saying they can do what nature does in 100K years in just 20. This is a rate of change with a slope 5000 times faster than the natural rate...and nobody seems interested in questioning it. It's one thing to achieve this in a lab experiment. Quite another at a planetary scale. And so, my point, with regards to forest fires, is two fold: The net effect is the same, meaning, CO2 in the atmosphere. Second, the CO2 generated per unit time isn't recovered at the same rate. It is recovered orders of magnitude slower. Therefore, forest fires are likely just as damaging (in terms of atmospheric CO2 accumulation) as burning any other fuel.