Comment by DoreenMichele | Hacker News Reader

Comment by DoreenMichele | Hacker News Reader

Rice paddies are responsible for 11% of the world’s methane emissions.

...researchers .. have discovered how to dramatically reduce the greenhouse gas emissions output of rice fields. Initial indications are showing a 70% reduction.

So ballpark: Looks like we could reduce (strikethrough: greenhouse gas) methane emissions by 7 percent or so a year while growing more rice to boot from this one change if enough farms adopted it and the article indicates that halfway through the planting season, farmers who had been reluctant to try it spontaneously changed to the new method simply because the crop yield was better:

Even when the pilot was halfway through, the crops were looking so healthy that a further 10 farmers in the village who weren’t part of the project chose to drain their land.

And I wondered what a 7 percent reduction in greenhouse gasses would do for climate change and found this opening paragraph:

Geneva, 26 November 2019 – On the eve of a year in which nations are due to strengthen their Paris climate pledges, a new UN Environment Programme (UNEP) report warns that unless global greenhouse gas emissions fall by 7.6 per cent each year between 2020 and 2030, the world will miss the opportunity to get on track towards the 1.5°C temperature goal of the Paris Agreement.

https://news.mongabay.com/2023/08/bali-rice-experiment-cuts-...

Unfortunately it's not that simple. If you look at the Wikipedia page on GHG [1], the warming effect of methane is maybe ~20% of the total GHG impact. So a 70% reduction of 11% of methane, which is a ~20% contributor is an overall warming improvement of ~1.5%. Which is still great, but not going to save the planet on its own.

[1] https://en.wikipedia.org/wiki/Greenhouse_gas

I didn't suggest it would single-handedly save the planet.

Though it's a fair point to clarify that rice is 11 percent of methane emissions, not 11 percent of total greenhouse gasses. There is a lot of math involved here that I don't know how to begin to navigate, frankly, to try to estimate just how big an impact this (potentially) is.

Some of what I view as core problem with approaching this issue is simply how easy it is to do the maths and say "but this is only a small impact in the greater problem".

- Air travel could be banned and we're still hosed

- All the cars could go electric and we're still hosed

- Kill all the cattle and we're still hosed

etc etc. It really is freerider/tragedy of the commons situation, lot of finger pointing and a lot of rational self interest. In the end I can only view this as unfettered good news, assuming we can scale it out

Our society is an extremely complex system.

We're consuming and polluting more than the environment can handle (overshoot).

Our economy, consumption and pollution is growing exponentially, in a finite environment (one planet).

It would be naive that in this point one single solution would solve our problems forever.

In fact, we should repair as many things as possible in one go, to get to the equilibrium as soon as possible.

Few things that could get us on the right track:

- remove the drivers of the exponential growth (reform the financial system, degrowth, ubi)

- speed up the transition to renewables (while we have fossil fuels, peak oil is not far away)

- stop polluting everything (plastics, pfas, pesticides/herbicides ...)

- reform agriculture (leading driver of deforestation and biodiversity loss, overfishing)

- plant based diets (animal ag. is 80+% of all agriculture, free an area the size of both Americas)

- reforest/rewild freed pastures to restore forests, biodiversity and water cycle (no monocultures, multi level canopies, no harvesting, old growth)

- by reforesting animal. ag. lands alone we could store enough carbon to cause new little ice age and reverse the warming

- reform / automate plant agriculture - repair soils, stop pesticides/herbicides (insects, pollinators)

I’m up for making this person dictator of earth.

Wish we could just do these things. It’s too bad, sometimes, that it’s so hard to generate political will and societal action.

> - All the cars could go electric and we're still hosed

I'm kind of amazed to learn that cars are only ~12% of GHG emissions: https://ourworldindata.org/emissions-by-sector

But we are on a good path...

The US, the EU, and China are all likely to have only ~30% of electricity coming from fossil fuels in 10 years, and only ~21% in 15 years, and only ~10% in 20 years.

In 20 years, it's likely less than 50% of cars on the road will be ICE.

~72% of GHG is energy. That number could easily be cut by ~50% in 20 years.

> I'm kind of amazed to learn that cars are only ~12% of GHG emissions

Yep. I am also very unclear that some of the sticks being wielded towards replacing existing ICE stock with new electric cars make sense. Sure my 7 year old petrol car is polluting, but building a brand new electric car to replace it is pretty horrible for the environment too?

The average ICE car uses ~4.6T CO2 per year (in gasoline).

The average electric car costs about ~9T CO2 to build.

Electricity in the US & the EU is currently ~60% fossil fuels.

Electric cars get >2x MPGe of the average ICE car.

So if you say the average car drives ~15k miles to produce ~4.6T CO2. The average electric car driven on ~100% fossil fuels for the same amount of miles would generate less than ~2.3T CO2. Since it's only 60% fossil fuels, it's ~60% of that = ~1.38T CO2.

Payoff is in about 3.33 years.

In ~20 years, when we get to ~10-15% of electricity coming from fossil fuel, the payoff would be only 2.2 years.

Sure, if you're driving a Toyota Prius now, and only putting on ~5k miles per year - you should probably just keep it til it falls apart.

Until we get to like <30% of electricity coming from fossil fuels - I'm not sure we should be encouraging people to needlessly upgrade their car to electric (unless they're getting like 12 miles to the gallon and driving 30k+ miles per year).

But, ideally, everyone would be thinking about getting at least a PHEV for their next car when they do upgrade.

Methane is 50x more potent at warming compared to CO2.

Methane emissions reduction should be considered the top priority despite representing only 20% of the total anthropogenic GHG.

Thank you. This is why I don't know how to approach the math.

I have a hand-wavy: This is potentially not quite 2 percent of total GHG emissions per year, but I don't know the weighted value of each type of gas and hypothetically something like 50 to 100 projects "like" this one each year for a decade gets us in the ballpark of stopping man made climate change.

Can 8 billion people produce 50 to 100 projects (each year) that move the needle this much? This works in part because it was initially a hard sell to get the farmers to agree to participate in the experiment but it went so well that halfway through the year, 10 more farmers chose to drain their rice paddies of water.

So you don't even have to talk people into taking a hit of some kind for the greater good. They will convert to this because of the higher crop yield and money in their pockets -- assuming (or as soon as) they can afford the transitional costs and a fund could be created to help with that to speed up adoption.

Methane is responsible for about 30% of the current global warming, so it clearly is a priority. That said:

Methane is transient, while CO2 accumulates. Methane decays quite quickly into CO2, which is why when accounted for over 20 years methane is considered 86x more potent than CO2, and over one century "only" 28x as potent. Any CO2 emitted today we will have to deal with for centuries to come. That's not the case for methane.

So while lowering methane will yield the most benefits in the short term, thinking longer term, it's really CO2 emissions that need to be lowered urgently.

Said differently, using a very crude reasoning with a hypothetical scenario: cutting methane emissions in 2025 rather than in 2050 would have little to no effect on the climate of 2100. In both cases the methane will have mostly decayed, and thus will stop capturing heat from the sun (maybe 2100 is a bit early, but you get the idea). But cutting CO2 emissions in 2025 rather than 2050 would have a dramatic effect on the climate of 2100, as these 25 years of CO2 emissions would mostly remain right there in the atmosphere.

It's obviously over-simplified, as global warming is having irreversible effects right now, and methane decaying will not revive species gone extinct in the meantime. So I'm certainly not arguing that we should not do anything against methane emissions. But that should not be done at the expense of fighting against CO2 emissions, rather on top of it...

I do not disagree but there’s one thing that should be considered right now: methane pockets in (melting) glaciers.

The phenomenon is “exponential” (or the first part of a sigmoid) precisely because of this chain reaction.

CO2 can be recaptured by forests eventually if we don’t destroy everything too quickly, thus why the immediate effect is really important.

> Methane has GWP (over 20 years) of 81.2[4] meaning that, for example, a leak of a tonne of methane is equivalent to emitting 81.2 tonnes of carbon dioxide. Similarly a tonne of nitrous oxide, from manure or paddy fields for example, is equivalent to 273 tonnes of carbon dioxide.

https://en.m.wikipedia.org/wiki/Global_warming_potential

Nevertheless the math on the impact is ~correct. It's very much a change worth making though.

This feels like the adage of marginal gains. Any one change by itself is small, but they compound. Used successfully by british cycling, I wonder if this would be similar?

It looks like the 1.5 C limit has already been missed. Even this year, we are nudging up against hitting it, and even if we stop CO2 emissions today, temperatures will probably continue to rise for hundreds of years.

Are you implying we shouldn't bother to keep trying?

While I'm here:

Y2K was supposed to be a global financial meltdown. Programmers versed in an "out of date" language fixed the issue beforehand, the first of January came while a lot of VCRs could no longer be programmed, the predicted banking system meltdown did not materialize.

Afterwards, some people went "Nothing happened. I was an idiot to pay you overtime." though nothing happened precisely because that overtime got paid.

The Kuwaiti Oil Fires were expected to burn for years and be a global environmental disaster. Crack teams from around the world converged on the country, invented new techniques on the fly and had them all out in six months.

This accomplishment was not met with global celebrations on par with the previous global handwringing. The desert bloomed like no one had seen in decades. This was a footnote in other stories with more drama.

When things run smoothly, everyone yawns and gets over it, often forgetting how bad it was supposed to be.

Bottom up efforts, like individuals, cities and states, would be best off just dealing with the effects of climate change. Build taller flood defenses. Build more desalination plants. Change crops. Upgrade AC units. etc.

Top down efforts, like global carbon quotas with enforcement via sanctions or even military action, are the only efforts likely to see success. So far, world leaders haven't shown interest in such things, but who knows, as world leaders get old and die and are replaced by the next generation, there might be interest in such a scheme.

> global greenhouse gas emissions fall by 7.6 per cent each year between 2020 and 2030

Which means that we need such a breakthrough every year, for 10 years.

I'm tired.

In my initial comment, I leapt from methane to greenhouse gasses. Someone pointed out the error and said methane is only 20 percent of all greenhouse gasses.

In a different comment, I said we need 50 to 100 such projects but I think I'm still just making errors in my head. It may be 5 to 10.

Since 1700, we've lost 85 percent of our wetlands. Peat stores a lot more carbon than forests.

I think this project makes it sound doable to find enough threads to pull to calm things down, but I'm really not coping well with the math which is likely convincing people I'm an idiot. People default to thinking this isn't fixable anyway. They need very little in the way of excuses to stand on that.

Reply on news.ycombinator.com