What does the amount of money have to do with anything? If someone found a way to reduce the $20 trillion US deficit by 0.09%, and someone said that it’s not significant, would it rate the snarky “well, then send me a check for that amount”?
Would you optimize a program by refactoring a function that used 0.09% of the execution time?
Yes, I often have done such refactoring. It's hard to get that last 20% of speed, much less last 5% without making a large number of small changes in code, usually after getting accumulated trace results (however presented.) .1% = one in one thousand. Keep stacking up those improvements and you do get somewhere, and often you'll easily find one hundred very small improvements in a day (10% altogether!) if it's green code, along with the bigger inefficiencies to fix. Not to mention that ignoring a presently-small inefficiency is predicting that future use won't swell that into a problem - which can be most unwise. Also, looking for tiny improvements gives you a good chance to stumble upon larger improvements you'd missed earlier. Optimize much?
You’re doing a lot of hand waving: “One hundred small improvements in a day” That’s a lot of work in an 8-10 hour day...
“if it's green code,..”
My point is that you don’t start by looking for 0.09% improvements when you’re profiling your code.
As for climate change, we are looking for cleaner energy options. The world’s energy use is going to increase greatly as billions more come out of poverty. China, for example, is going to increase nuclear energy to be almost on par with the US over the next decade:
But the point, precisely, is that the amount is actually a lot of money for most countries, never mind a single person. That any attempt at any real economy can't ignore 1 in one thousand - especially if it might balloon 100x. Not sure you really read carefully.
Would you optimize a program by refactoring a function that used 0.09% of the execution time?