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Comment by mistrial9 | Hacker News Reader

Before jumping into detailed discussion of the points raised in the publication here, including "trees leak methane in the Amazon" -- is it possible that this article is getting promoted because it feeds into a "they dont know what they are talking about" meme of anti-science know-nothing'ness ?

There appear to be several sets of weasel-words candidates .. Such as "many scientists applaud X but some urge caution" without naming either side's strengths and weaknesses, notable refutation on either side, or any raw counts of how many "some" are...

Recently it was discovered that USA oil and gas industry self-reporting of methane emissions on extraction in the Permian Basin might be five times less than actual numbers, and might have doubled in the last two years. This was detected by satellite sensors and NGO analysis.

http://www.edf.org/NewMexicoMethane

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> is it possible that this article is getting promoted because it feeds into a "they dont know what they are talking about" meme of anti-science know-nothing'ness ?

I would go further and say it's not only possible, it's likely.....similar to how articles from the opposing viewpoint are promoted, also often full of weasel words to some varying degree depending on the specific topic. Much of science discussion in the mainstream is actually a bit of a meme war, but this has probably always been true.

Daniel Dennett: Memes 101 | How Cultural Evolution Works

https://www.youtube.com/watch?v=5fG-3f4f0hA

Replace religion with "fundamentalism, of any kind":

https://pics.ballmemes.com/the-one-thing-that-i-think-is-rea...

Doesn't methane dissolve relatively quickly in the atmosphere so it's not a long term threat like CO2 so once you run the numbers amortize it all a tree that leaks methane but eats carbon is a net win so long as the carbon actually stays out of the atmosphere?

It turns into CO2. So all that happens is an initial spike of a more potent GHG turning into a baseline GHG.

And the half-life is a ~decade, with constant replenishment that's enough to have a significant effect that the same carbon emitted as CO2 would not have.

Methane oxidizes in the atmosphere with a half life of about 10 years. CO2's equivalent half life (due to ocean absorption) is 27 via a quick google.

So they're really not that different. Neither is a "long term" threat -- if we stopped emissions entirely the climate would be expected to return to a pre-civilization equilibrium on the scale of decades.

> Neither is a "long term" threat -- if we stopped emissions entirely the climate would be expected to return to a pre-civilization equilibrium on the scale of decades.

That only can be true if the resultant warming over those decades isn't significant enough to kick off other feedback loops or cause ecosystem collapse. For instance, the caps melting and lowering the planetary albedo, ocean acidification, etc. If these things happen too quickly, you're going to see a serious and nasty extinction event happen. Sure, not all life forms will die - archaea are pretty hearty after all, but it isn't going to be pretty for most complex lifeforms adapted to the climate of the current era.

Yeah. If the phytoplankton goes and stops renewing free oxygen; it becomes pretty hard to be a mammal in a relatively short time.

Could it also be possible that the current rate of emissions beefed up the planet's scrubbing capacity, and the climate return to pre-civ levels even faster?

The temperature impulse response of CO2 does not seem to have a half-life of 27 years if you look at page 711 of the IPCC report.

https://www.ipcc.ch/site/assets/uploads/2018/02/WG1AR5_Chapt...

Yes, and on page 712:

> Figure 8.29 Development of AGWP-CO2, AGWP-CH4 and GWP-CH4 with time horizon. The yellow and blue curves show how the AGWPs changes with increasing time horizon. Because of the integrative nature the AGWP for CH4 (yellow curve) reaches a constant level after about five decades. The AGWP for CO2 continues to increase for centuries. Thus the ratio which is the GWP (black curve) falls with increasing time horizon.

That is, CO2 greenhouse forcing continues for centuries. Back when I worked on this stuff, we used an approximate half life of 250 years. But it's really more complicated. That IPCC report says this, on page 737:

> No single lifetime can be given [for CO2]. The impulse response function for CO2 from Joos et al. (2013) has been used. See also Supplementary Material Section 8.SM.11.

From Joos et al. (2013):[0]

> The CO2 response shows the known rapid decline in the first few decades followed by a millennium-scale tail. For a 100 Gt-C emission pulse added to a constant CO2 concentration of 389 ppm, 25±9 % is still found in the atmosphere after 1000 yr; the ocean has absorbed 59±12 % and the land the remainder (16±14 %).

0) https://www.atmos-chem-phys.net/13/2793/2013/acp-13-2793-201...

That's pretty different from what I have heard elsewhere. Could you please provide some references so I could read further?

Here is a link that argues the opposite side: https://www.skepticalscience.com/co2-residence-time.htm

Exactly:

"What really governs the warming potential is how long the extra CO2 remains in the atmosphere. CO2 is essentially chemically inert in the atmosphere and is only removed by biological uptake and by dissolving into the ocean. Biological uptake (with the exception of fossil fuel formation) is carbon neutral: Every tree that grows will eventually die and decompose, thereby releasing CO2."

Thanks for your perspective.

> if we stopped emissions entirely the climate would be expected to return to a pre-civilization equilibrium on the scale of decades.

Do you have any links to research which backs up this quote? Because I would love to believe it.

OP here. No climate scientist, just someone who's been following climate change for a couple decades. Not a climate change denier by a long shot, if anything I've actually already made a bunch of large life decisions under the assumption that climate change is going to change this world quite a bit in the next few decades.

The main accusation you make, that I (and other who are promoting this article) are suggesting that the scientists don't know what they are talking about, I actually plead guilty for that. I really do think we don't know what we're talking about anythign other than the primary assertion that we are warming this planet through our actions. I don't believe we actually have a real handle on the rate (we could be drastically under or overestimating) of climate change, and I definitely don't think we have an inkling on whether geoengineering efforts would work the way we expect it to.

The main light bulb for me from this article is it has made me consider even planting trees as a geoengineering effort, as vicarious as other proposals like dumping iron in the ocean or particles into the stratosphere. Right now I would consider any effort at controlling global warming other than actually just reducing emissions as geoengineering.

The most apt analogy I have found for geoengineering efforts like this was given by the comedian Bill Burr in a podcast, where he shits on a Ted talk about genetically engineering malaria mosquitos (https://youtu.be/vEZ0z0WSrUA ).

I have seen similar over-confidence among my fellow scientitsts in biology, in complicated subjects like cancer, immunology and metabolism. Time and again, people will assert they have understood a system, make a drug, and it won't work, and then they will blame the failure on the same complexity they said they had conquered.

We have made tremendous progress on all these scientific fronts (biology, climate science, etc) but the systems under study have become so complex, I would consider it a criminal offense if any scientist makes a claim that they really have figured out all the ramifications of their geoengineering plans. Criminal because I am worried that any major geoengineering effort if it goes wrong might be irreversible. Orders of magnitude more studies are needed IMO to make sure we understand these systems, and I don't think we are going to invest that effort until things get far, far worse. Until then I would prefer we err on the side of caution.

Btw it's not just methane, they actually talk about a bunch of other potential issues (like VOCs) in that article. Also, this is nature mag, if you think nature mag is anti-science or climate change denying I'm not sure who else you think is your ally.

Hey ramraj07, I just wanted to say thanks for submitting this article!

A couple weeks ago I read a different article on Nature that claimed that "Restoring natural forests is the best way to remove atmospheric carbon" (https://www.nature.com/articles/d41586-019-01026-8).

I added it then to some notes I've been taking, listing evidence for and against claims, which I was able to update quite a bit today using information from the article you posted: https://www.wikiclaim.org/index.php?title=Increasing_foreste...

FUD tactics are certainly an issue to keep in mind, but I do like to be able to consider all the available evidence when assessing claims. Thanks!

> we could be drastically overestimating

Would you mind explaining this bit? Besides [1], which hardly changes the big picture and came out literally last month, what evidence have you seen in the last couple decades of following climate change that suggest to you that the likelihood that we have been "drastically overestimating" the rate is anything comparable to the likelihood that we have been correct (if not underestimating)? From as far back as I can remember, the predictions have only stayed about the same or gotten more dire. They used to say weather patterns would get more intense, with more storms etc., and they indeed have. They say sea levels would rise and I really have no reason to believe they cannot calculate the rise correctly. I would think that if climate scientists had no idea what they're talking about, we could point to their erroneous predictions and prove them wrong?

[1] https://www.nationalgeographic.com/environment/2019/03/one-p...

I definitely am not refuting the estimates by climate scientists about our worsening climate rates; I will totally assume that the rate they suggest is the expected value until proven otherwise.

However, I will also not be surprised if things get far worse extremely fast, or if they actually suddenly start getting better (or slowing down). My only rationale for this belief is that as we go into warmer and warmer climate, we are also going into a territory that the scientists themselves have no real data for - literally uncharted territory. I'm sure they have run models to extrapolate their predictions but the actual fact that we are already experiencing climate that has not been seen for however amount of time means any prediction has to be taken with a slight grain of salt.

Practically speaking, we always hear of the finding that global warming might release methane bodies or it's turning into a runaway chain reaction. We don't even know how many other chain reaction scenarios exist that have not even been considered. Similarly (though with orders of magnitude less likelihood even for me), there exists possibilities that excessive warming into uncharted temperatures might trigger some feedback that might slow this warming too. I'm not counting on it but I am not ready to % exclude it yet either.

> there exists possibilities that excessive warming into uncharted temperatures might trigger some feedback that might slow this warming too.

I very much doubt this is the case.

What is happening to the world can be explained by science and using scientific principles the changes can be predicted by modelling.

The hard part is creating the model, only because the problem domain is very complex. But what we have seen, is over time that modelling has been getting better.

Now if there was some possibilities that excessive warming into uncharted temperatures might trigger some sort of cooling effect then surely that would have come out in the modelling.

You're right we're not sure, but splitting the difference like this sounds like you're equivocating the two possibilities. "Oh, it could get worse, it could get better, we just don't know." When the reality might be a 90:10 relative likelihood in a particular direction.

It's a sad state of affairs when we dismiss everything we don't agree with as some conspiratorial piece of fake news. Yes, that type of content absolutely exists, but we should not let that excuse intellectual dishonesty.

'notable refutation on either side, or any raw counts of how many "some" are...' - Why does it matter to dig into why one side is right or wrong? Earth atmosphere is complex beyond imagination of any person/society and you should expect science (or anyone else)to be wrong most of this time at what they have to say about this topic.

Don't be hell-bent on trying to comprehend mechanics of Earth atmosphere and finding 'scientific' solution to climate change. If you are aware of what has worked well until now for earth's climate then why not just follow it?

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