Roland Emmerich. And from a book by Art Bell! …of all people. Not known for hard scifi.
Some examples are better than others.
They are… different! How they are different and why the movie might have chosen to go with the “wrong” one for the real-life event on which the opening scene based. Larsen B Ice Shelf. Continental ice vs glacial ice.
Arctic/antarctic events and affect on the thermohaline circulation. The Younger Dryas event as an irl historical example of extreme climate shift which still took decades longer than the events of the film.
Human records. Ice Cores! Meteoric ice. Tree rings! Water body beds! Caves!
Age and layers. Ash, gas, life, temperatures from oxygen isotope ratios.
Colbert’s insights from The Supercomputing Conference. The big data; it is very big.
… which are the name we’ve made up for the misnomered “hurricanes” that seem to form over land in the movie. Air flow. the Coriolis effect, thermodynamics and superfreezing in the center of the storm.