The atmospheric half life of methaine is just under 10 years. So if you release 1k lbs of methaine in 10 years there will be 500 lbs left 10 years after that ther will be 250 ect.
It’s complicated. The breakdown of methane in the atmosphere depends on hydroxyl radicals that are created at a regular rate. If you have more and more methane released, and/or you have other chemicals that also react with those radicals, the overall average half life will increase. Both those things are happening, so the old half life really isn’t as accurate as it used to be. Guess which number the IPCC still uses for its models though.
I mean, it’s more clear than 0.5 tons, since “tons” doesn’t specify US or metric. Not that it would matter in this specific instance.
Indeed that’s 10 hundredweight. Which maybe ironically enough is rather intuitive for me, Germany still uses pounds and hundredweight (Zentner) in informal and sectorial use, meaning 500g and 50kg.
1k lbs is a perfectly cromulent unit of enbiggenment, colloquially known as “Calebs”.
