is the long-term pattern of temps, wind and rainfall on earth.
this is proven to be very diff from the past to now.
Ice Ages
about 2 bilion yrs ago, was the 1st ice age and since then, the earth has cycled between warm (no ice at all, even at the poles) and cold periods (ice ages)
Snowball Earth / Slushball Earth
about 650 million years ago, earth was covered in ice and scientists weren't sure if everything was completely frozen.
scientists still don't completely understand what caused this from a time where the continents positions were not like now.
