Polar bears in the southern latitudes have been accustomed to ice-free summers since well before the Industrial Revolution.

WSJ: Are Polar Bears Really Disappearing?

It is a cracked and crumpled layer-cake of rocks, 480 million years in the making, a landscape sculpted by ice then transformed by man and a witness to the birth of the Industrial Revolution.

UNESCO: Global Geoparks

The research shows that a one-degree temperature variation that took 11 millennia to occur since the end of the last major ice age has now been replicated in 150 years, since the early days of the Industrial Revolution.

WSJ: Earth Hotter Now Than Most of Past 11,000 Years

Before the Industrial Revolution, carbon dioxide levels were around 280 ppm, and they were closer to 200 during the Ice Age, which is when sea levels shrank and polar places went from green to icy.

NPR: Experts: CO2 Record Illustrates 'Scary' Trend