There has been a lot of talk recently about the possibility that the earth was cooler much earlier than was previously believed. This article from Scientific American gives a good introduction:
There's something that bothers me, but I'm not sure if it's a valid question. What I'm wondering is, I believe our current assumption is that the earth was once very hot, and the heat that the earth has now is a remnant of that initial heat. So in other words, the earth is slowly cooling from that early Hadean period.
So the obvious (to me) question is, if the earth was cooler at an earlier date, what does that do to the equations about the current temperature? Wouldn't the current temperature also be lower? I'm thinking maybe that the cooling off is reverse-exponential, if that's the correct term, so a large difference at the beginning would only lead to a negligable difference today.