"What point would that be and how was it proven?"
We are discussing the difference between the Arctic Circle and the Antarctic Circle. Here are the basics...
1. Antarctic surface temps are, on average, 50 F colder than the Arctic (I've seen 43 F to 60 F, so I averaged and rounded down. NOBODY disputes that when air flows over the Antarctic, it cools more than it does going over the Arctic, something in the ballpark of 50 F. That's the "air conditioner" at work cooling Earth's atmosphere.
2. Antarctica pumps 9 times the ice into the oceans vs. the Arctic, and 46 times the molecular H20 that the Mississippi River pumps into the Gulf. That Antarctic ice is also much colder than the ice from your freezer. The Russians found -200 F deep in the Antarctic Glacier about 10 years ago when they were drilling to a lake covered by ice for 50 mil years. Since the Antarctic dumps 9 times the ice into the oceans vs. the Arctic, it cools the oceans more too...
The difference is entirely WHERE LAND IS. 90% of Earth ice is on Antarctica. 7% is on Greenland. So 97% of Earth ice is on the two land masses closes to an Earth pole.
Look and notice. The Earth's two "AC units" have settings 0=off to 10=maxcool. The Arctic is set at 1, and the Antarctic is set at 9. THAT is what dictates Earth's current climate. Have a look...
This one below is set at 1...
and this one is set at 9....
So perhaps LAND NEAR AN EARTH POLE HAS SOMETHING TO DO WITH EARTH CLIMATE CHANGE....
because if we had two polar oceans, Earth would have NO ICE...