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.