Our air conditioning may break down in the next few years. Not the mechanical one we can flip on with a switch, the one that works to keep the globe cooler.

Our northern polar ice cap has hit a new melting low. Five years ago, the cap shrunk to about 4.17 million square kilometers over the summer. This year’s melt shatters that once record-breaking number, the cap shrinking to 3.41 million square kilometers.

So aside from less ice cooling off the ocean, how does this affect the climate?

Turns out the color of the ice plays a big factor in how the cap keeps out planet cool. White objects reflect heat, while darker objects absorb it. So the greater the expanse of white ice up at the top of the world, the more of the sun’s rays are bounced back out into space. When that ice is replaced  by darker ocean waters, that free-flowing H₂O acts as a sponge, not a reflector. Which means warmer waters, less ice, and eventually, higher sea levels at ports all around the world.

We’ve heard about how the shrinking cap affects species such as the walrus and polar bear, and therefore indigenous people that depend on arctic animal populations to continue their way of life. But it turns out smaller ice caps could affect our weather systems, too.

Temperatures are rising at a faster rate at the poles than towards the equator. The difference in temperatures is what maintains the jet stream, the winds that keep weather systems on the move from west to east. Without that difference in temperature, the jet stream could slow, causing heat waves or rain to stall for long periods of time over one spot — a potentially devastating prospect for crops.

But even researchers are unsure exactly how these changes will play out. I’ll defer to the experts on this. Research scientists at the U.S. National Snow and Ice Data Center discovered this summer’s drastic melt. Walt Meier is one of those scientists.