Hacker News Reader

Comment by xyzzyz | Hacker News Reader

> So, perennial rice may end up reduce GHG emissions substantially.

Not really. These GHG emissions from rice are in steady state with the amount of CO2 and methane in the atmosphere. They do not add additional GHG to the atmosphere the way burning fossil fuel do.

When you burn fossil fuels, the carbon atoms released into atmosphere have been captured from the atmosphere millions years ago. When weeds and other organic matter in flooded fields decompose, released carbon atoms have been captured only a couple of months or years earlier.

View on HN

Methane and CO2 are very different things. The former has a massively greater warming effect than the latter, and takes long enough to degrade in the atmosphere that it can significantly affect warming times. If you aren’t paying attention to the rising methane levels in our atmosphere (and possible evidence of a feedback loop) with serious trepidation, you’re a lucky person who probably sleeps well at night.

> Serious people panic when I do.

But you didn't address why you panic.

wrong thread?

Comment was edited.

I want a warmer atmosphere.

All the UN data points to a warmer atmosphere equating to more food and higher quality of life.

I concede some concern about potential feedback loops, but the reality is that earth was and still is in an ice age. Ice ages are not the norm on earth, I think it’s okay if we exit an ice age. Yes things will change, but it’ll be over decades to millennia. We’re working on carbon capture right now — 150 years after the start of the Industrial Revolution.

By even the most imo insane estimates we are 50-70 years from even minor discomfort. I’m fairly confident we can fix the problem when it becomes a problem

> I want a warmer atmosphere.

> All the UN data points to a warmer atmosphere equating to more food and higher quality of life.

Globally and to a point, maybe. But that's not taking into account local effects and the millions (billion?) who'll be displaced and what comes with it

Then you have ocean acidification, postivie and negative feedback that we won't be able to stop, &c.

> I’m fairly confident we can fix the problem when it becomes a problem

I’m fairly confident that the same UN data points, and basically the entire corpus of text about climate science, will show you that it's absolutely not how it works because the inertia is way too strong to only care about it when it's in front of you

Also, it is already a problem for billions of people every year and we haven't found a fix except emitting less CO2.

I somewhat agree. A climate several degrees warmer than recent history seems like it would be beneficial; in the past, warmer periods coincided with a lush and rich biosphere. More energy is available to life.

Like you, long-term, I'm more worried about the upcoming ice age than runaway global warming. We know how to fix global warming, and will in the next hundred years: Nuclear and solar.

But... warming can still be very disruptive in the short term. Coastlines moving a few hundred feet might be disastrous for entire regions. Staple crops failing in one nation and blooming in another may cause refugees, famine, and war. Politics is local.

Last summer we had heat waves and droughts on three continents simultaneously, plus massive unprecedented floods in Pakistan. It doesn't take much to destroy a year's worth of crops, and the IPCC modeling doesn't really come to grips with what we're seeing.

That was actually part of early models of climate change, but we’ve already crossed the point where the negatives from increased CO2 outweigh the positives.

The problem is there are just so many small negatives such as extremely warm weather negatively impacting plant growth. But also less talked about problems like the increase in outdoor CO2 requiring more building ventilation to avoid indoor CO2 levels from giving people headaches. That’s right, global warming actually makes meetings inside air conditioned buildings worse.

> All the UN data points to a warmer atmosphere equating to more food and higher quality of life

All data point to countries warmer than Spain having significant drops in life expectancy. Human body is less healthy in a tropical climate than it is in continental climate.

A numbwr of cities will exceed 36 degrees C Wet Bulb Temperature in the summmer. Do you understand what that means? Over heating to death. Sweating does not work any more.

Everyone living in those areas will become refugees.

We are also losing all snowpack. No snowpack means droughts in summer and floods in winter.

Lastly, we expect climate change to cause food shortages. It will not bw just poor countries that suffer. Nations will respond by banning food exports. Britain depends on imported food, it has not been self-sufficient for 100 years

We have no crops that handle high heat well. We neber domesticated perrenial plants properly, they give much lower yields. Perrenial wheatgrass has half the yoeld of wheat.

Potato planta shut down in high heat even if you provide them with water. You can turn the entire field i to soup, at 40 degrees potatoss don't grow.

It is sad that most people do not comprehens the huge cost we will have to deal with this problem.

I live in northern Spain and I notice the summers and the winters getting hotter.

This winter I didn't turn on the heat once and it was uncomfortable cold inside the house for like three days tops. It's normally uncomfortable at least for one or two months.

On december it's freezing outside at night, this december we had flowers blossoming. What an issue right? Energy and money savings on all that gas and it's more comfortable outside.

Well we beat the last hot temperature record last summer with 45⁰C, that's "kills your grandpa temperature" or 113F if you prefer. I'm scared of this summer, I don't have AC.

That’s very misleading because Methane is extremely front loaded in its effects. Year 0 is very bad year 50 is only equal to the amount of carbon in that methane. As rice farming is very consistent year to year, and rice removes carbon as it grows the net effect on future warming is ~zero because all the previous years have already been baked in to current conditions.

The great news is reducing Methane from existing sources is one of the fastest ways to reverse climate change after we reach net zero.

That math isn’t mathing. With the rice field active, there’s more methane in the atmosphere every year, compared to the world where the rice field doesn’t exist.

It’s climate change.

If global methane from rice fields is identical in 2000, 2023, and 2050 … it has zero impact on climate change.

Rice cultivation isn’t completely static, so the it’s changes in rice cultivation that result in climate change.

Rice cultivation hasn't been a factor in climate for all time, only relatively recently. The increase in methane can have an accumulating warming effect. Think about it like this - the amount of rice fields is the derivative of climate change. If you increase the amount of rice fields once and don't decrease it, climate change will slowly but surely rise, even if rice fields don't increase.

No, that’s not the case, because the methane doesn’t accumulate. If you increase the amount of rice under cultivation, the methane content in atmosphere will stabilize after around 20 years, and after that there will be no more climate change resulting from the rice fields.

Yeah, but it will stabilize at a higher level than it would otherwise have been.

I'm not saying the methane accumulates, but the additional energy in the whole earth system does. Every year with additional methane has an effect. If you have no rice fields, then rice fields for a couple of years, and then again no rice fields, you'll have increased methane levels for those years. If you compared that earth to another one without those years of increased levels, the one without would be less warm.

Remember: climate change is not a derivative, it's an integral.

No, the energy doesn’t accumulate in Earth over time. Disregarding the energy of radioactive decay within Earth, the Earth is in steady state with respect to energy. All energy it receives from the Sun is radiated away promptly. The greenhouse effect works by delaying this radiation. The more the radiation is delayed by, the more energy is buffered in steady state. Make no mistake though: all of the energy from the Sun is radiated away rather quickly.

> If you compared that earth to another one without those years of increased levels, the one without would be less warm.

No, after the methane from the fields decays to CO2, both would be the same.

> All energy it receives from the Sun is radiated away promptly. The greenhouse effect works by delaying this radiation. The more the radiation is delayed by, the more energy is buffered in steady state. Make no mistake though: all of the energy from the Sun is radiated away rather quickly.

This is easily disproven. The Earth does trap heat - we can measure this, it's called the Earth Energy Imbalance. This imbalance has been rising since more greenhouse gases were introduced: https://www.nasa.gov/feature/langley/joint-nasa-noaa-study-f...

The amount trapped is rising because we retain the same input longer. A fraction of the total heat is radiated away (not all of it, and not "rather quickly"). If that fraction drops more heat will be trapped.

Now you have a system with additional energy due to additional greenhouse gases. Over time the gases will reduce, but the radiation is still only a fraction of the total heat! Of course over time this will very slowly trend back towards the same temperature, but even when the gases themselves have returned to previous levels, the additional heat will take a number of years to be radiated away.

That’s true, but we’ve been cultivating rice for thousands of years. When people talk about returning the earth to pre industrial levels that’s a world with significant rice cultivation going back long enough to account for such differences.

The global energy imbalance is simply lag before temperature’s equilibrium, when you turn up the heat in your house it takes longer to heat your fireplace than a wood door. That same effect takes longer on the scale of the earth but it’s an exponential decay. Compared to the history of rice cultivation you very quickly get to millions of a degree difference in surface temperatures. We just keep adding ever more greenhouse gasses.

> That’s true, but we’ve been cultivating rice for thousands of years.

How much rice did we previously cultivate, and how many of those fields were flooded? Around 1900 the world population was around 2 billion, so I feel confident in assuming that we've since strongly increased the amount of farms. As such I don't see how this matters. Cultivation is not a boolean state.

> The global energy imbalance is simply lag before temperature’s equilibrium, when you turn up the heat in your house it takes longer to heat your fireplace than a wood door. That same effect takes longer on the scale of the earth but it’s an exponential decay.

Yes, this is what I've been saying. Increasing the amount of methane in the atmosphere by increasing rice production will lead to an increased temperature even after you stop.

> Around 1900 the world population was around 2 billion, so I feel confident in assuming that we've since strongly increased the amount of farms

Actually not so much, due to vastly increased agricultural output per acre the tendency is to have less acres under cultivation. https://www.statista.com/statistics/196104/total-area-of-lan...

Further agriculture has also reduced quite a bit of methane production by draining swamps etc. So it’s difficult to do direct comparisons even just back in 1900.

> Increasing the amount of methane in the atmosphere by increasing rice production will lead to an increased temperature even after you stop.

That’s true of CO2 across the next few decades but not methane because it breaks down so fast. Assuming net zero CO2 the lag would be in the other direction where it would get colder for several years after you stopped.

> Actually not so much, due to vastly increased agricultural output per acre the tendency is to have less acres under cultivation.

Your source shows data for America between 2000 and 2022. Why do you think that is a good source for the topic at hand?

> Further agriculture has also reduced quite a bit of methane production by draining swamps etc. So it’s difficult to do direct comparisons even just back in 1900.

There is no reason to do so, my argument is not affected by it in any way.

> That’s true of CO2 across the next few decades but not methane because it breaks down so fast.

No, breakdown time doesn't affect anything, since I'm specifically talking about the time after it broke down. If you understood my comments differently, try re-reading them in that light.

> Assuming net zero CO2 the lag would be in the other direction where it would get colder for several years after you stopped.

Am I understanding you correctly - you believe that temperature is like a pendulum, where after a period with increased greenhouse gases, it will somehow swing to be colder than it would have been without that period? Why do you think so, and how do you believe this to work from a thermodynamics perspective?

> Why do you think that is a good source for the topic at hand?

The obvious downward line even as population and farm output increased prove your argument was completely false. That’s as much as I care to prove. Do some damn research.

> Am I understanding you correctly - you believe that temperature is like a pendulum, where after a period with increased greenhouse gases, it will somehow swing to be colder than it would have been without that period? Why do you think so, and how do you believe this to work from a thermodynamics perspective?

Hell no. I am saying if the level of greenhouse gasses drops there will be lag in the other direction. There’s nothing special about the direction of lag it’s simply a delay before equilibrium.

Clearly you haven’t understood what I said or the topic at hand and need to do some actual research before you keep spouting more nonsense.

Yikes, you (singular) just got rather uncivil. Such a shame, as you (plural) were doing so well.

I don’t consider someone being disingenuous as being civil in a discussion.

> The obvious downward line even as population and farm output increased prove your argument was completely false. That’s as much as I care to prove. Do some damn research.

"The obvious downward line" is not relevant since it's for a time period that is only starting to affect todays climate. I was previously talking about time periods which would already be affecting the climate today. What if through the use of modern machinery and fertilizer the land use started trending down slightly in the 80s, and rose rapidly before then? We don't know, which is why your statistic is fully irrelevant to this discussion. I'm not interested in simplifying complex systems like historical agriculture to "line goes down now, line must have been going down before".

Maybe "do some damn research" that looks at the content in the context of the discussion.

> Hell no. I am saying if the level of greenhouse gasses drops there will be lag in the other direction. There’s nothing special about the direction of lag it’s simply a delay before equilibrium.

I really, really think you should try to re-read my previous comments. This doesn't make any sense. Let's play through it with numbers - maybe you'll show me I've been a complete idiot.

Let's define a starting point of greenhouse gases and temperature, both start at 0. We are in an equilibrium. Now we increase greenhouse gases to 1, and after some time temperature will also increase to 1 (arbitrary values). Then we decrease greenhouse gases to 0 (previous equilibrium). It will take some time until the temperature goes back to 0.

Referring back to the comment I was replying to: where do we get colder compared to a reference earth without increased gases?

That's my whole argument, it's what I've been writing the whole time. The increased greenhouse gases lead to a higher temperature, which will (until it goes back to equilibrium) be increased compared to if there was no increase in greenhouse gases, and it will stay increased for a while after greenhouse gases are at equilibrium.

What exactly are you arguing against? It seems you're taking stabs at whatever sentence you feel is incorrect, but I haven't seen a coherent argument.

More complaining zero research, why I not surprised…

> where do we get colder compared to a reference earth without increased gases?

Wow. Suppose it’s fall and someone says “the days are getting colder.” Do you assume it’s in relation to some arbitrary point thousands of years ago or last month?

Context is often implied in the written word, and you seem to have issues following normal conventions. I don’t mean this as an insult, but there’s probably some adult education classes that you might find helpful.

If you're not arguing for that, what exactly are you arguing for? What have I said that you disagree with? I've tried laying out my argument multiple times very clearly, but you're choosing to engage in ad-hominems instead. Seriously, what is that last paragraph, if not a giant insult?

I'm trying to have a normal and calm conversation. If you're not capable of responding in kind, don't respond. You're going on about how I'm not doing research, while you're not even responding to my criticism of your previosu statistic. Seriously, if you think that statistic had any value for this conversation: then yes, I'm fully incapable of doing what you consider research.

10,000 years isn’t relatively recently on the scales of human civilization nor how quickly the climate feedback loops operate.

Okay? I don't see how this is relevant? All I was saying was that there was a point in time without rice cultivation, and another one with rice cultivation. The point with cultivation has higher levels of methane. Even if you were to return to the point without cultivation, the period with cultivation will have lead to an increased temperature.

It’s relevant because you said relatively recently then chose a completely arbitrary yet undefined point. Once you start talking about periods before written or oral records we have little basis for comparison to say if it was good or not. Why not chose the last ice age, or even periods with higher than current global temperature as the baseline?

I stay by that. On a climate scale, scaled-up rice production has started a short time ago - which is why I wrote my initial comment: looking at the climate right now and extrapolating that current rice farming has no impact on climate change is illogical.

There is no “long term climate scale.” Climate responds relatively quickly to changes.

Sorry, but what exactly are you arguing for? Of course you can view the climate at different time scales, and of course you can refer to those time scales by colloquial terms. Climate shows cyclic behavior at the time scales I was referring to: https://www.fs.usda.gov/ccrc/education/climate-primer/natura...

You could have asked for what I was referring to, but instead you chose to jump in with your definitions. Have you had conversational success with this approach?

Can you elaborate on this?

Do you mean that rice plants are actually absorbing methane earlier on, so they're just releasing the same amount?

Or are they actually producing methane from other molecules, like water and carbon dioxide?

Because yes, methane breaks down in the atmosphere into H2O and CO2 so you could view it as a cycle, but the more rice there is the higher the steady state methane in the atmosphere is, so it's still a problem.

Yes, the whole point is that it is a cycle. The fields don’t affect by much the total number of carbon atoms in the atmosphere. Without the fields, other plants would grow there, then die, decay, and release carbon into atmosphere.

At best, growing rice and flooding fields might affect the balance between the amount of methane and amount of CO2 in the steady state, but this is of no practical consequence, because the methane will not accumulate year over year, like the emissions from fossil fuels do.

Suppose we grow twice as much rice as we do now. This means that the steady state will have twice as much methane coming from the fields as it has now. Hell, let’s actually assume that all existing methane in atmosphere is from rice fields, and actually increase amount of methane in atmosphere by a factor of 2. What is the impact to the climate, according to our current models? Well, this is equivalent to less than 10% increase in total CO2 in the atmosphere. That’s like a difference between 2000 and 2020, which is to say, almost unobservable — and remember I assumed we increase total methane by factor of 2, not just methane from the fields.

> but this is of no practical consequence, because the methane will not accumulate year over year, like the emissions from fossil fuels do.

Methane still takes 12 years to break down in the atmosphere, and it's more than 25 times as potent of a greenhouse gas than CO2.

CO2 concentrations are currently ~420 ppm, while methane is ~1866 ppb, or 1.9 ppm. If we assume methane is 25 times worse than CO2, that 1.9 ppm is the equivalent of 48 ppm CO2. Which is gigantic.

Doubling steady-state methane levels in the atmosphere would be a major problem. It would be like CO2 levels going from 468 to 516, yes a 10% increase. I don't know how you can call that "almost unobservable" when we're doing our absolute best to stop any increases. The fact that it's steady state doesn't really matter if it's still a major contributor, and/or if that steady state is increasing.

Thank you for redoing the math I did, and confirming I was exactly correct with figures.

The increase in concentration is observable, but the impact on climate is not. Again: this increase is similar to increase between 2000 and 2020. Without extremely careful and precise measurements, nobody would really be able to perceive any difference in climate between these two dates.

This matters, because it is the perceived effect of climate change that is worrying, not the measured one. Modern science can measure many things with very high accuracy, but these changes only matter if they affect our lives in a way we can perceive. If the change is only seen on accurate scientific instrument, why should the society care much about it?

> If the change is only seen on accurate scientific instrument, why should the society care much about it?

It’s difficult to perceive this as anything but elaborate climate denial, given it works for any incremental progress towards lower emissions.

No, you missed the point: there is an enormous difference between methane emissions from fresh organic matter, and emission from fossil fuels. The latter accumulate, while the former do not. That’s why as we continue incrementally burning fossil fuels, the effects accumulate and affect climate over decades or centuries, but decaying weeds or (fashionable to discuss a couple of years back) cattle burps and farts do not.

The point is that even if it continues over the centuries, the effect of cattle farts and weeds decaying on rice fields will only ever be observable using precise scientific instruments, whereas effect of burning fossil fuels for centuries will be very readily perceivable with very crude techniques.

> the effect of cattle farts and weeds decaying on rice fields will only ever be observable using precise scientific instruments, whereas effect of burning fossil fuels for centuries will be very readily perceivable with very crude techniques

It’s a fine distinction, and I’m glad you made it, but the arguments for why it doesn’t matter don’t stick. Gross imperceptibility does work for any small amount of any emission—there is no way to feel the effect of that emission per se. There is also the case that raising the planet’s steady-state temperature is exactly what existing fossil fuel emissions have done. They’re a problem even if they’re already there.

> but the arguments for why it doesn’t matter don’t stick

I'm not so sure. GP's argument was that when people say rice/cattle release so-and-so much methane into the atmosphere per year, the fact that it's a cycle and the amount of methane & CO2 in the atmosphere due to rice/cattle remains constant is usually ignored.

Meanwhile, burning fossil fuel, increasing air traffic (-> water in the atmosphere), etc. actually increase the total amount of green house gases in the atmosphere, year by year.

Sure, we could think about reducing the constant amount of methane in the atmosphere due to cattle/rice by reducing cattle/rice but, in light of emissions due to fossil fuel accumulating year by year, this doesn't seem to be the most pressing issue by a large margin.

> this increase is similar to increase between 2000 and 2020. Without extremely careful and precise measurements, nobody would really be able to perceive any difference in climate between these two dates.

If that's how you work then nothing has any impact whatsoever, cars, planes, cattle, over twenty years if you split everything in sub categories they're all negligible

Meanwhile we clearly already can measure the effect of it all.

With your logic you're the proverbial boiled frog my friend...

From https://news.ycombinator.com/newsguidelines.html :

> Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith.

Why unnecessarily double down on this very hypothetical scenario,

> Suppose we grow twice as much rice as we do now. […] Hell, let’s actually assume that all existing methane in atmosphere is from rice fields, and actually increase amount of methane in atmosphere by a factor of 2.

when GP's main point was: Absorption & emissions by rice plants are in a steady state – they emit methane into the atmosphere, it breaks down to CO2 and water over the course of a few decades, and then the plants absorb the CO2 again.

As a consequence, as long as the number of rice plantations doesn't increase, the amount of methane in the atmosphere due to rice will stay largely constant. There will certainly be fluctuations because, as was mentioned:

> At best, growing rice and flooding fields might affect the balance between the amount of methane and amount of CO2 in the steady state,

but

> this is of no practical consequence, because the methane will not accumulate year over year, like the emissions from fossil fuels do

and the current total amount of methane in the atmosphere due to rice (which, again, is constant) – on its own – does not have devastating effects, as outlined by GP's hypothetical argument of doubling the amount of rice in the atmosphere. Put differently, reducing the amount of rice plants in the world would not provide any leverage against global warming.

The rice plants don't absorb or release methane, the breakdown of organic matter in the flooded ricefields causes the release of methane. In dry/unflooded fields, the decay would be much slower. The flooded fields possibly emit more methane and less CO2 than unflooded due to anaerobic conditions, but I'm just guessing.

Not true between CO2 and methane. The total amount of carbon is the same but in methane form is worse for greenhouse effect.

Methane is worse, but it again doesn’t matter here, because the fields are in steady state not only with CO2, but with methane as well.

Methane doesn’t linger in atmosphere forever, it decomposes into CO2 in a decade or so. This means atoms of methane emitted from the fields are pretty much exactly paired with atoms of methane in atmosphere decaying into CO2.

This means that methane emitted from the fields doesn’t increase the total amount of methane in the atmosphere, the way burning fossil fuels does with CO2.

This reasoning is completely wrong: there's an input and an progressive decay as output, the amount of methane in the atmosphere at any given point is directly related to the input.

Yes, this is exactly what I say in my comment. The amount of methane in the atmosphere is directly proportional to the input rate. That’s why, as I said, in steady state, when the we keep steady the amount of rice under cultivation, the amount of methane in atmosphere is not changing over time.

Can you point to which part exactly is “completely wrong”?

> Can you point to which part exactly is “completely wrong”?

First you said:

> Not really. These GHG emissions from rice are in steady state with the amount of CO2 and methane in the atmosphere.

And then now

> That’s why, as I said, in steady state, when the we keep steady the amount of rice under cultivation, the amount of methane in atmosphere is not changing over time.

These two statements are contradictory. If we assume steady state, then yeah the amount of methane is stable, but changing the way we cultivate rice is the opposite of steady state: if we reduce the methane emissions, then the amount of methane in the atmosphere will decrease that's it.

There is no contradiction between these two statements. They both say the exact same thing: if rice cultivation is in steady state, the amount of CO2 and CH4 in atmosphere due to it is constant. You next say if we change the steady state, the amount of methane in atmosphere will change, but that again is not a contradiction with what I said.

So you eventually agree with the statement you disagreed before, that is:

> perennial rice may end up reduce GHG emissions substantially.

(because that's the starting point of this conversation, and it's the opposite of steady state)

That doesn't make sense mathematically.

Because you could start with zero methane in the atmosphere, just lots of CO2, but the rice would introduce methane.

Eventually yes you can get to a steady state of methane, but the point is that the more rice there is, the higher that steady state becomes. Which is bad.

So the total amount of methane would absolutely increase. (And if you stopped planting rice at all it would eventually decrease over the subsequent decades.)

Yes, I discuss this in my comment here

https://news.ycombinator.com/item?id=35483780

The point is, though, that the amount of methane that currently have in atmosphere, is only barely relevant when it comes to how it affects climate from human perspective. If all methane disappeared tomorrow, our climate would be back to 2010, which is hardy a significant change. Nobody would even notice other than climate scientists. Similarly, if we increase the rice cultivation, the amount of methane will increase in the steady state, but the increase will be wholly immaterial, so that it does not affect us in any real way. This is not really “bad”.

>our climate would be back to 2010, which is hardy a significant change.

Uh, no. It is quite significant, and a mountain of evidence says that the climate changes from concentrations in the last decade are very significant. You appear to be a denier of anthropogenic climate change who is willing to make silly straw men arguments.

I do happen to remember what the climate looked like in 2010, and I very much do not believe that enormous social and economic projects are warranted to revert the state of climate by 10 years.

> You appear to be a denier of anthropogenic climate change who is willing to make silly straw men arguments.

You appear to be unable to discuss the issue on merits, but this doesn’t necessitate resorting to ad hominem. You can do better than that.

Actually describing the beliefs that you hold is not an ad hominem.

You, however, are claiming that they are unable to discuss the issue - that is.

> Actually describing the beliefs that you hold is not an ad hominem.

There is not a single thing I have said in this thread that can be interpreted as “denial of anthropogenic climate change”. You are welcome to find it and quote it though. On the other hand, there are many places where I very much reaffirm the reality of anthropogenic climate change, for example

Well, we can start with how you pretend that greenhouse gas concentration determines the current temperature, and not the rate of change of temperature. I bet you aren't stupid, so it's either willful ignorance or disingenuity.

I think they are right.

Yes, the more rice there is, the higher the steady state would be.

However, we aren't planting more rice. The ammount of rice grown and methane released is already in steady state.

This is a seperate point than if atmospheric methane would go down if we grew less rice than today.

If you grow more people, we will have more rice. If perennial rice is more profitable, then corn acreage will shrink in favor of rice acreage.

Your assumption of steady state is incorrect. The carbon that is being released as methane would otherwise be accumulated in the soil.

Not the OP but: Sure, rice does cause some non-zero amount of CO2/methane in the atmosphere that would otherwise remain stored inside some other plants (or the soil) but, unless we increase rice plantations around the world, this amount will remain constant. Hence, it's a steady state.

Methane is 20x worse, so if you capture 95% of the carbon and emit the rest as methane, you've broken even on GHG. But nothing I'm aware of captures 95% of carbon. Terra Preta might lock up the captured carbon for 100's of years, but producing charcoal is 50% efficient if you optimize for emissions, which most people do not.

That’s reassuring we are in steady state. If perennial rice takes over, we will gradually drop atmospheric methane to a lower steady state.

Reply on news.ycombinator.com