It’s actually basically nothing if you do the math…
Let’s assume 50 million macs for a half hour at an average wattage of 20W TDP, wolfram alpha tells me worth that’s 360 metric tons of co2 , or about 24 USA citizens worth of co2 for a year. 24 <<< 300 million people in the USA, apple isn’t having much impact. I’d argue windows would be far worse anyway…
Building a 13" MBP produces ~200kg of CO2[1]. Taking GP's 50 million figure we get 10 billion tons of CO2. Very generously assume each one gets 1000 updates, you end up with 360,000 tons of CO2 total for all of these updates, or about 0.0036% of the cost of building them in the first place.
There are actual benefits to delta updates but the environmental impact isn't one of them.
