Delegates from 196 countries in Paris this week managed to sign a critical deal to tackle global warming, but the hard task of actually implementing the promises begins now. At the heart of the matter is the fact that the world will see dangerous, possibly catastrophic, changes in weather patterns if average temperatures rise by 2 degrees Celsius above pre-industrial levels. So far we have already touched the 0.8 degrees Celsius mark.

The political agreement relies on research and projections by climate scientists around the world. One of the most obvious and scary impacts of climate change is the melting of polar ice caps, with cascading results.

Advertisement

The more this ice melts, the more sunlight will be absorbed by the dark surfaces underneath, expediting the warming process. This also increases the chance that disease-bearing microorganisms locked in the ice will be released. A new study from Harvard University has even found that melting ice caps could be making the world rotate a little slower.

That isn't the end of it. The more polar ice melts, the more sea levels will rise. A rapid decline of Arctic ice has already been documented and videos of chunks of ice caving off massive northern glaciers have gone viral on the Internet. Scientists studying the Antarctic, a much more solid block of ice, have found that its contribution to sea level rise will also be significant - about 10 centimeters by 2100.

Advertisement

To drive home the danger of climate change and sea level rise, scientists have been mapping out the worst case scenario of what the world would look like if all ice melted. In 2013, National Geographic showed how this would lead to oceans rising by 216 feet, the water significantly redrawing the world map and drowning many coastal cities. This video from Business Insider Science shows exactly which global cities will be underwater if that happens.

If that’s not enough, here a projection from Climate Central on the view from the ground when our earth is 2 degrees Celsius hotter, and when it 4 degrees Celsius hotter. In either case, the Gateway of India in Mumbai would turn into one of those monuments you only can see by boat and Kolkata would have disappeared, and entire coastlines would have been struck off the face of the earth.