Wildfires help slow down global warming?

[TylerM4]

This last week or so it's been at least 5* cooler than what it would normally have been if it weren't for all of the wildfire smoke.

So my question is: Is this smoke helping to combat global warming? Is it doing the opposite of a "greenhouse gas" and keeping the heat out vs trapping it in? I realize that wildfires produce a lot of CO2 which is a greenhouse gas, but that C02 will eventually be reclaimed as the burnt foliage regrows while the heat that was reflected back out to space should never return.

If there is an impact, I imagine it would be small. Wildfire smoke in only covering a very small portion of the planet.

Thoughts?

[Jlabute]

It is impossible to know. Anyone who tells you otherwise is selling you something. There are too many variables other than just CO2 and you do not know how much each contributes to control global temperature, and we don't know how sensitive the atmosphere is to changes in CO2. There is not just CO2, but cloud cover, solar radiation in all spectrums, earth's tilt and orbit, magnetosphere, albedo of surfaces, all of which change. BC, California, Australia wild fires are typical, but very tiny, and only momentary. They do not contribute anything that one can measure and distinguish with instruments in a global average scenario.
Who is to say what causes global warming or cooling? Earth has had multiple ice ages over millions of years when CO2 was 6000ppm down to 300ppm, so can't be exclusively controlled by man made components.

Thinking about such things is a mental exercise you'll never have an answer for, but the fires are good for the forests.

[TylerM4]

It's certainly a complex topic with all sorts of variables/factors.

I was hoping to simplify the discussion by limiting the question to "Does it help" rather than trying to quantify how much it may help.

From a purely intuitive level - it appears it does in the short term at least. Temps are lower when skies are smokey.

[GordonH]

This planet largest consumption of co2 is from fully grown trees, each adult tree consumes 48 pounds of co2 each year. That doesn't sound like a lot, until one thinks of number of trees worldwide.

Each hectare of forest can have between 1,000 to 2,500 trees. So based on low end 1,000 × 1,216,053 hectares burnt last year = 1,216,053,000 × 48 = 58+ billion pounds of co2 not consumed.

These numbers are just for BC on just last year forest fires.

Wonder how trees burnt last year worldwide, I suspect it's mind blowing.

Each adult tree will consume 48 pounds of co2 yearly.

[Glacier]

Let's say that the temperature is 5C cooler during the day and 0C cooler at night (smoke doesn't really impact the lows) for 10 days during the year because of the smoke. That equates to 0.07C for the entire year. So, no that's not enough to overcome the 1.0C warming we've experienced in the past 150 years.

[Jlabute]

It's certainly a complex topic with all sorts of variables/factors.

I was hoping to simplify the discussion by limiting the question to "Does it help" rather than trying to quantify how much it may help.

From a purely intuitive level - it appears it does in the short term at least. Temps are lower when skies are smokey.

I suppose if large meteor strikes and volcanoes can cause temporary global cooling and/or extinctions, why can't smoke have an effect too. Smoke has an albedo effect, so once all the dust and smoke settle, you'll be left with pretty close the same conditions as before the smoke. If (and a big if) global warming were based solely on CO2, and there is more CO2 in the atmosphere after all the dust and smoke settle, then temperatures would again just jump back up a little higher than where they left off. Assuming we don't account for any ocean cooling or other sorts of earth systems that store energy. All the effects of smoke are short term.
So my intuition tells me, smoke is good for local temperatures, and fires are good for forests, global warming is slowed down although not detectable, and no effect long term since accumulative effect is insignificant.

[StraitTalk]

Some earlier pointed out that trees absorb an incredible amount of CO2 every year. They left out the part where when the trees burn, this CO2 is released back into the atmosphere. This goes far beyond the shade that smoke plumes provide or the sunlight they reflect back into the atmosphere. I can assure you that British Columbia's carbon footprint is pale in comparison to that of our burning forests.

Environment Canada estimates that for every acre of primarily coniferous forest burned, approximately 4.81 metric tons of carbon is released into the atmosphere—between 80 percent and 90 percent in the form of carbon dioxide (CO2), with the rest as carbon monoxide (CO) and methane (CH4). (Environment Canada - 2006) That's before vegetative decay. That's before calculating for the loss of future CO2 absorption from those forests.

https://www.canada.ca/en/environment-cl ... hange.html
(I copied a broken link, but I got it from here)

The last estimate I heard on BC's carbon footprint was just north of 60 million tonnes. If you find out how many acres has burned you can start doing the math.

[TylerM4]

Some earlier pointed out that trees absorb an incredible amount of CO2 every year. They left out the part where when the trees burn, this CO2 is released back into the atmosphere. This goes far beyond the shade that smoke plumes provide or the sunlight they reflect back into the atmosphere. I can assure you that British Columbia's carbon footprint is pale in comparison to that of our burning forests.

Environment Canada estimates that for every acre of primarily coniferous forest burned, approximately 4.81 metric tons of carbon is released into the atmosphere—between 80 percent and 90 percent in the form of carbon dioxide (CO2), with the rest as carbon monoxide (CO) and methane (CH4). (Environment Canada - 2006) That's before vegetative decay. That's before calculating for the loss of future CO2 absorption from those forests.

https://www.canada.ca/en/environment-cl ... hange.html
(I copied a broken link, but I got it from here)

The last estimate I heard on BC's carbon footprint was just north of 60 million tonnes. If you find out how many acres has burned you can start doing the math.

You should think bigger when it comes to CO2 and trees/forests.

An established forest is actually CO2 neutral. Decomposing plant material lets off the same amount of CO2 as burnt plant material. A section of forest that hasn't burnt in the last 100years is doing nothing to remove excess CO2 from the atmosphere because the old decomposing plant material lets off as much CO2 as the growing plants consume.

As I implied in my original post. The CO2 that's let off by a fire is eventually recovered by the forest as it regrows. But the heat that's been reflected back into space will never return.

[StraitTalk]

The CO2 that's let off by a fire is eventually recovered by the forest as it regrows. But the heat that's been reflected back into space will never return.

But that same forest could have existed without the fire and absorbed mankind's CO2 instead. *wink*

I agree with everything you're saying, I only mean that fires are assuredly having a large impact on global warming as a whole, just not necessarily anthropogenic warming although there is probably an argument to be made there.

[TylerM4]

But that same forest could have existed without the fire and absorbed mankind's CO2 instead. *wink*

I agree with everything you're saying, I only mean that fires are assuredly having a large impact on global warming as a whole, just not necessarily anthropogenic warming although there is probably an argument to be made there.

I don't think you get it. Established forests release as much CO2 as they absorb.. Many people such as yourself think that forests somehow gobble up carbon but that's not the case.

Global warming is a slow slow process taking many years. The burn/regrowth process could speed up global warming 1 year if it's a bad fire year, but it'll slow the following years as all that CO2 is re-captured as plant material. In the end, forest fires are part of a carbon-neutral cycle.

[goldpot501]

So the catastrophic global *warming* is still a buzz word?

[TylerM4]

So the catastrophic global *warming* is still a buzz word?

I think the general scientific community now accepts that global warming is indeed occurring. Still lots of debate as to how fast it's occurring, how much an impact mankind has had on the process vs part of a natural cycle, etc.

[StraitTalk]

But that same forest could have existed without the fire and absorbed mankind's CO2 instead. *wink*

I agree with everything you're saying, I only mean that fires are assuredly having a large impact on global warming as a whole, just not necessarily anthropogenic warming although there is probably an argument to be made there.

I don't think you get it. Established forests release as much CO2 as they absorb.. Many people such as yourself think that forests somehow gobble up carbon but that's not the case.

Global warming is a slow slow process taking many years. The burn/regrowth process could speed up global warming 1 year if it's a bad fire year, but it'll slow the following years as all that CO2 is re-captured as plant material. In the end, forest fires are part of a carbon-neutral cycle.

I am afraid you are grossly oversimplifying this, and the effect forests have. Please refer to: https://cfpub.epa.gov/roe/indicator_pdf.cfm?i=86

"The total amount of carbon stored in U.S. forests increased by 10 percent between 1990 and 2013,
with every year during this period experiencing a net increase (Exhibit 1). Thus, since at least 1990,
U.S. forests have served as a net sink rather than a net source of carbon. In 2013, the most recent
year for which emissions data are available, carbon storage in forest ecosystems offset
approximately 11 percent of the nation’s greenhouse gas emissions (U.S. EPA, 2015)."

Just because earth is a closed system doesn't mean that the worlds forests are invariable.

[Poindexter]

I think the increased number of fires indicates were witnessing a positive feedback cycle. This is where a fire releases green house gasses, which contributes to warming, which contributes to more fires. Also called a destabilizing loop.

Scientists however calculate it represents only 5 to 10 percent of global CO2 emissions. Not good but probably not yet enough to create a destabilizing loop. Give it a few years at this pace however and that will probably change.

It's complicated: While CO2 causes long-term warming, aerosols can have both a warming and a temporary cooling effect.
snip
they estimate that wildfires make up 5 to 10 percent of annual global CO2 emissions each year.

https://www.google.ca/amp/s/insideclima ... -co2%3famp

Edit: missed some words, didn't make sense. Should really get better at proof reading.

[StraitTalk]

https://www.egu.eu/news/428/deadline-fo ... -below-2c/

When you look at timelines like this, absolutely ANYTHING that releases a significant amount of CO2 in the short-term is a bad thing.