Maybe they will gain again as they have done before. You cannot say that they won't.
Here's the problem: Yes, non-manmade factors like solar irradiance can cause the earth to get colder.
BUT THEY ALREADY ARE. The earth should be getting colder right now. Which means more than 100% of the warming we're seeing is man-made.
No it isn't. The Earth goes through periods of warm and cold and what is happening is nothing abnormal.
We're going into a cold cycle and the earth is getting hotter, how do you not get that that's abnormal?
It's like if there's a fire burning in your house, and you go "Fuck it's hot, I wonder if it's this fire," and someone goes, "Dude, it just gets hot and cold sometimes, that's normal, every August is hot," BUT IT'S FUCKING NOVEMBER AND YOU HAPPEN TO KNOW THE HOUSE IS ON FIRE.