Why is 1.5 degrees such a big deal? Because to warm our entire planet up by 1.5 degrees Celsius requires a lot of heat.
All this extra heat melts glaciers, which raise sea levels. If the ice sheets of Antarctica and Greenland melt completely, millions of people's homes will be under water. The extra heat also intensifies weather, making wet places wetter, dry places drier and increasing the ferocity of storms.
That 1.5-degree increase also won't be distributed evenly. The coldest nights in the Arctic might get 10 degrees warmer. The warmest days in Mumbai might get five degrees hotter.
Over the past 10,000 years, we've been lucky. Earth's climate was stable and our civilizations flourished. But as our climate gets more unstable, so will our economies and our societies. We'll all suffer, and the vulnerable will be hit hardest, unless we act now.
[Countdown Take action on climate change at Countdown.ted.com]
